Colon Mucosal Cells after Combined Radiotherapy And Chemotherapy
A. PLESKOVIČ1, R. ZORC-PLESKOVIČ2, O.VRASPIR-PORENTA2, M. ZORC2, D.PETROVIČ2...............................................……………………………………………..156
1Division of Surgery, Clinical Department of Abdominal Surgery, University Medical Centre Ljubljana, Ljubljana, Slovenia
2Institute of Histology and Embryology, Medical Faculty, University of Ljubljana, Ljubljana, Slovenia
Corresponding author: Danijel Petrovič, Institute of Histology and Embryology, Medical Faculty of Ljubljana, Korytkova 2, 1105 Ljubljana, Slovenia. Tel.: 386 (1) 543 7361; e-mail: daniel. email@example.com.
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Selective Gap Junctional Communication within the V79-4 Chinese Hamster Cell Line
Research Institute of Child Health, Department of Cell Biology, Brno, Czech Republic
Corresponding author: Jiří A. Vítek, Research Institute of Child Heath, Department of Cell Biology, Černopolní 9, 662 62 Brno, Czech Republic. E-mail: vitek firstname.lastname@example.org.
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Self-Initiation of Translation of mRNAs Devoid of Translational Initiators in Escherichia coli
V. KOLEV1, A. BERZAL-HERRANZ2, I.VANOV1 …………………………………….171
1Department of Gene Regulations, Institute of Molecular Biology, Bulgarian Academy of Sciences, Sofia, Bulgaria
2Department of Molecular Biology, Instituto de Parasitologia y Biomedicina „Lopez-Neyra“, Consejo Superior Investigaciones Cientificas, Granada, Spain
Corresponding author: Ivan. G. Ivanov, Institute of Molecular Biology, Bulgarian Academy of Sciences, „Acad. G. Botchev“, bl. 21, 1113 Sofia, Bulgaria.
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CD8-like Molecules on Human Spermatozoa
D.K. DIMITROVA1, Ts. Ts. MARINOVA2
1Laboratory for Reproductive Immunology
2Laboratory for in Vitro Fertilization and Preimplantation Embryology, Department of Biology, Medical University, Sofia, Bulgaria
Corresponding author: Tsvetana Ts. Marinova, Department of Biology, Medical Faculty, Medical University, 2 „Zdrave“ Str. BG – 1431 Sofia, Bulgaria. Tel.: 359(2) 51 66 781, Fax: 359 (2) 952 03 45; e-mail: email@example.com.
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Monoclonal Antibody Register
New Monoclonal Antibodies to Rat Testicular Antigen, TEC-21
I.HÁLOVÁ, L. DRÁBEROVÁ, P. DRÁBER
Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
Corresponding author: Petr Dráber, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 20 Prague 4, Czech Republic. Fax: 420 (2) 4147 0339; e-mail: firstname.lastname@example.org.
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Abstract. The aim of this study was to investigate early histological and stereological changes in enterocytes. Lymphocytes, mast cells, serotonin- and somatostatinsecreting cells in colon mucosa the first day after the end of combined radiotherapy and chemotherapy. For experimental model 20 Beagle dogs were used. Ten dogs were given plational every 5 days over 20 days and they were irradiated 20 days with 32 Gy (every second day with a fractional dose of 3.2 Gy) onto the whole pelvis and tail. Another 10 dogs represented a control group. For detection of apoptosis the TUNEL technique was used whereas immunohistochemical methods were performed for deection of somatostatin – and serotonin-secreting cells, and for proliferating cell nuclear antigen in epithelial cells. The volume density of enterocytes in apoptosis was increased, and Vy of paracrine cells (mast cells, somatostatin and serotonin positive cells) was significantly increased in the treated group compared to the control group. In the treated group a significantly lower Vy of lymphocytes and PCNA-positive enterocytes was shown compared to the control group. The results of our experiments showed that combined radiotherapy and chemotherapy caused loss of enterocytes early after the therapy. It was associated with an increased volume density of paracrine cells. These morphological changes in the colon mucosa might be the earliest changes leading to disruption of the mucosal barrier, malabsoption syndrome, stenosis, inflammation and other complications resulting from the radiotherapy and chemotherapy.
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Abstract. The probability of cell-to-cell coupling between directly adjacent cells (communication capability) in the V79-4 Chinese hamster cell line was evaluated under standard conditions or after 18-h treatment with EG. The cell monolayer did not form a continuous network of cells interconnected via gap junctions, but an average cell was coupled to only one half of its directly adjacent neighbours under standard conditions, or to one third of its directly neighbouring cells after 18-h exposure to EG. The rest of the directly adjacent neigbours did not establish functional gap junctions with an injected cell, although they were completent to couple to other cells with a probability similar to that of the coupling between the injected cell and its diredt neighbours. Moreover, all the cells pssessed the identical connexin – cx43, present on all cell membranes. The results indicated that the choice of a cell to which neighbour be coupled was rather random in the standard cell population as a whole, although the population contained some clones whose capability to couple was more or less different from that of the original cell population. Ethylene glycol reduced the gap junctional communication by increasing the frequency of cells not coupled to any of their direct neighbours from 1 % for untreated cells to 23,3% for cells exposed to EG, and consequently by reducing the number of directly adjacent cells coupled to communicating injected cells. The communication capability of the cell population appered to be unstable. It varied slightly in time and so did the response of the cells to EG. The results indicate that a cell can control its coupling to different directly adjacent neighbours independently, being able to control the gap junctional communication not only in time but space as well. All control mechanisms of GJIC, known so far, affect a cell as a whole, while our results indicate that another regulatory mechanism may exist, controlling, the gap junctional communication to different adjacent neighbouring cells independently.
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Abstract. Recent studies have shown that the canonical SD-anti-SD interaction is dispensable for the initiation of translation of certain m RNAs in Escherichia coli. In this study the cat and tetR genes were modified to either destroy complementarity to E. coli 16S RNA or cempletely delete their 5´non-translated regions. Thus a series of cat- and tetR-derived genes were constructed, cloned under a strong constitutive promoter and expressed in E. coli cells. The efficiency of expression was evaluated by the yield of CAT (for the cat gene) and cell viability in increasing concentrations of antibiotic ( for both cat and tetR genes). The obtained results show that the mRNAs transcribed from both series of reporter genes (cat and tetR) were active in vivo. Their activity was preserved even in the cases when the lenght of their 5´non-translated leader sequences was reduced to one nucleotide for the cat gene and eight nucleotides for the tetR gene. The yield of protein obtained with the latter constructs was detectable and sufficient for bacteria to survive at 50-100 micro g/ml tetracycline, respectively.
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Abstract. The object of the present study was to investigate whether there differences in the presence of CD8-like molecules on human ejaculated spermatozoa from fertile donors and subfertile patiens ( with leuco-cytospermia). In our previous report we defined CD4- like molecule heterogeneity on normozoospermie and globozoospermic human spermatoza. In this investigation the results from indirest and absorption ELISA, as well as the indirect IEM and IIF findings, demonstrated the presence of CD8 immunopositive spermatozoa in all samples studies. The ELISA data showed that anti-human MoAb CD8 recognized an epitope common to the human spermatozoa with normal morphlogy and foetal thymocytes. During absorbtion experiments MoAb CD8 was preincubated with spermatozoa and allowed to react with thymocytes. A significant decrease of the reactivity was obtained for MoAb CD8 by ELISA. Localization of the antigenic determinants, identified by MoAb CD8, in the acrosomal region, in the neck and on the sperm-tail plasma membrane was defined in normozoospermic samples. Similar in localization but different in intensity, CD8-like sperm immunoreactivity was found in leucocytospermic damples in comparison to normozoospermic samples. The obtained results proved the heterogeneity in the presence, localization and expression of CD-like antigen determinants on human spermatozoa and enlarged the information obout CD8-like antigen characteristics of the spermatozoa from fertile donors and subfertile patiens.
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TES 101 is a 38-kDa glycoprotein expressed in mouse spermatocytes and spermatids within the seminiferous tubules but not any other tissue (Kurita et al., 2001). In mouse testes it is first detectable approximately on day 20 after birth. Its function has not yet been elucidated. However, because the expression is almost parallel to testicular growth, the molecule may have a significant physiological role in sperm formation. This suggestion is supported by recent data indicating that this protein is higlhly conserved in mammals. We have recently cloned cDNA for a rat homologue, the TEC-21 glycoprotein (BLAST accession nuber AF347056), which exhibits an 80% identity with TES 101 at the amino-acid level.Both TEC-21 and TES101 glycoproteins are found exclusively in testicular tissue and are first expressed at similar developmental stages. Interestingly, TEC-21 is also expressed in rat basophilic leukaemia (RBL) cells, which have been extensively used as a model cell line for analysis of the high-affinity IgE receptor-mediated activation of mast cells and basophils. TEC-21 is a heavily glycosylated glycoprotein bound to the plasma membrane via a glycosylphosphatidylinositol (GPI) anchor. It has apparent molecular masses between 32-36 kDa in rat testes and 36-42 kDa in RBL cells. The TES101/TEC-21-like protein was also identified in human testes (50% of identity with TEC-21 at the amino-acid level; BLAST accession number AAK27310). Thus, monoclonal antibodies (mAbs) against the TEC-21 glycoprotein could become useful reagents in research on the role of this protein in male germ-cell maturation. Because TEC-21, like other GPIanchored proteins, is associated with lipid rafts in RBL cells, antibodies against TEC-21 would provide a valuable tool for the analysis of the role of lipids rafts in mast cell signalling (Dráber et al., 2001).
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