Volume 47 (2001) No. 5

Volume 47 (2001) No. 5

Genetically Modified Dendritic Cell-Based Cancer Vaccines 
J. BUBENÍK ...................…………………………………………………………………153 
No abstract.
Full text. 153-155

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. petrovic@mf.uni-lj.si. 
Full text. 156-157 158 159 160 161-162

Selective Gap Junctional Communication within the V79-4 Chinese Hamster Cell Line
J.A. VÍTEK……………………………………………………………………………….163
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 jiri@mbox.vol.cz. 
Full text. 163-165 166-167 168-170

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.
Full text. 171-173 174-175

CD8-like Molecules on Human Spermatozoa
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: tmarin@medfac.acad.bg. 
Full text. 176-177 178-179

Monoclonal Antibody Register 
New Monoclonal Antibodies to Rat Testicular Antigen, TEC-21
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: draberpe@biomed.cas.cz. 
Full text. 180-181 182

Colon Mucosal Cells after Combined Radiotherapy and Chemotherapy

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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Selective Gap Junctional Communication within the V79-4 Chinese Hamster Cell Line

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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Self-Iinitiation of Translation of mRNAs Devoid of Translational Iinitiators in  Escherichia coli

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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CD8-like Molecules on Human Spermatoza

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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Monoclonal Antibody Register
New Monoclonal Antiebodies to Rat Testicular Antigen, TEC-21 

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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