Articles
- Electron-Microscopic Immunocytochemical Study of the Intracellular Transport
- of the Viral Glycoproteins in ts1, a Mutant of Moloney Murine Leukemia Virus
- R. ROUSSEV1, E. SHIKOVA1, V. SOVOVÁ2, J. ŠTOKROVÁ2,
- M. ALEXANDROV1
- The transport and localization of env-proteins of ts1 virus (a paralytogenic
- temperature-sensitive mutant of Moloney murine leukemia virus) in infected
- cells of the TB cell line have been studied at the ultrastructural level. It was
- found that the envelope precursor polyprotein gPr80-env of ts1 was inefficiently
- transported out of the endoplasmic reticulum at the restrictive temperature.
- It was speculated that inefficient transport correlates with inefficient processing
- of gPr80env into gp70 and Prp15E and leads to paralytic disease.
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- I and Phase II Xenobiotic Biotransformation in Different Inbred Strains of Rats:
- Study in Immobilized Perfused Hepatocytes
- S. HYNIE, V. KØEN1, M. MRÁZ, H. FARGHALI
- The present study was designed to compare phase I and phase II biotransformation reactions in immobilized perfused hepatocytes as a cellular system obtained from inbred rat strains which represent models for some cardiovascular diseases, namely, spontaneously hypertensive rats (SHR), rats sensitive and resistant to
- isoprenaline-induced myocardial lesions (IS and IR, respectively) as compared to Wistar rats (W). The biotransformation kinetics for hexobarbital (HX), 7-ethoxycoumarin (7-EC), 1-chloro-2,4-dinitrobenzene (CDNB) and 4-nitrophenol (4-NP) were followed up in the hepatocyte perfusate. W and SHR rat hepatocytes have metabolized HX at a higher rate than those of the IR and IS strains. Hepatocytes from the W strain exhibited a higher rate of 7-EC deethylation activity compared to hepatocytes obtained from IR or IS strains. Hepatocytes obtained from SHR and IR rats showed the highest glutathione-S-transferase (GST) activity towards CDNB compared to the IS or W strain. 4-NP disappearance was higher in the perfusion medium of hepatocytes obtained from the W and IS strains compared to the IR strain. These significant differences in drug biotransformation between various studied strains, which may be genetically determined, can be well demonstrated by using an efficient drug metabolizing model of the immobilized perfused hepatocytes. The importance of these differences should be considered during the study of the experimental therapy of the relevant disease as obtained from the specific experimental strain, where it may be expected that the pharmacokinetic profile of a drug in vivo and consequently its pharmacodynamic or toxic effects will be strain dependent.
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- Different Activity of Adenylyl Cyclase in Prefrontal Cortex in Three Rat Strains. The Effect of Amphetamine
- V. KLENEROVÁ, P. ŠÍDA, S. HYNIE
- Since the literature data do not provide enough information on the effects of amphetamine on the prefrontal cortex and since many controversial findings were reported in various rat strains we decided to compare adenylyl cyclase activity in the prefrontal cortex in various rat strains and test the effects of chronic amphetamine treatment (for 14 days) on the activity of this enzyme. Basal adenylyl cyclase activity was lower in Wistar rats than in Sprague-Dawley and Lewis rat strains. Amphetamine treatment produced in Wistar rats a substantial decrease in basal adenylyl cyclase activity. In Sprague-Dawley rats, we observed the highest enzyme activity which was slightly reduced after amphetamine treatment. In Lewis rats which had basal activity close to the activity of Wistar rats, amphetamine produced an increase in enzyme activity. The total adenylyl cyclase activity, estimated in the presence of forskolin, was the lowest in Wistar rats. The highest stimulation was observed in Lewis rats. Amphetamine treatment caused a very significant inhibition of total adenylyl activity in Wistar rats and a smaller inhibition in Sprague-Dawley rats. However, in Lewis rats amphetamine treatment increased the dose-response curve of forskolin stimulation. These results show that Lewis rats, compared to the other two strains, develop not only quantitatively but also qualitatively different responses.
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- Predictive Value of HLA Class II PCR Typing for the Outcome of Mixed Lymphocyte Reaction
- V. CUKROVÁ, M. LOUDOVÁ, I. ŠRÁMKOVÁ, L. DOLEŽALOVÁ,
- A. VÍTEK
- The use of HLA-DRB1 and -DQB1 polymerase chain reaction-sequence-specifie primer (PCR-SSP) typing at different levels of resolution for MLR prediction was assessed in 54 HLA-A and -B matched donor/recipient unrelated pairs and 89 HLA-A and -B identical siblings. Graft-versus-host (GvH) direction one-way MLR was evaluated unlessstated otherwise. The typing of DRB1 alleles satisfactory for MLR prediction in HLA identical siblings (P = 0.0015) does not appear to be sufficient in matched unrelated pairs (P = 0.2407). Using more discriminatory PCR-SSP typing, the disparity in DRB1 allelic subtypes was predominantly found in the category of DRB1 allele compatible, MLR positive unrelated pairs. Besides, DRB1 allelic subtype mismatches were revealed in five of the forty-one DRB1 allele compatible, MLR negative unrelated pairs. More discriminatory typing made the correlation between DRB1 compatibility and MLRnegativity extremely significant (P = 0.0001). As for these five exceptional cases, the reciprocal host-versus-graft (HvG) direction MLR was considered, too. This allowed HLA-D disparity to be disclosed in two of them. An uninterpretable result reflecting defective MLR reactivity occurred in one case. Negative reciprocal MLR in the last twoDRB1 allelic subtype incompatible pairs is hardly to explain without postulation of MLR silent DRB1 allelic subtype mismatches. An analysis in unrelated pairs showed a role of some DQB1 gene products in the proliferative response too. GvH direction positive MLRwas found in two HLA identical siblings among the 89 tested. The DPB1 incompatibility detected in one of them could be a potential cause of proliferative response but MLR reactivity in the other, DPB1 identical, pair cannot be interpreted easily.
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- Cytogenetic Changes in Sprague-Dawley Rat Lymphomas in the Course of in vivo Passages
- M. SLADKÁ, B. OTOVÁ
- Changes in the karyotype in three spontaneous Sprague-Dawley rat lymphomas
- (SD7/95, SD8/96, SD9/96) have been studied in the course of in vivo passages.
- In individual lymphomas karyological findings of primary disease from lymph nodes were compared with changes found in the 1st and 10th passages of the lymphoma and bone marrow samples. Chromosome studies were performed on direct preparations using the G-banding technique. Chromosome counts of all specimens studied were near diploidy, the majority of metaphase cells being pseudodiploid. In later passages of two lymphomas,the tendency in selection to hyperdiploid karyotype, particularly in bone marrow was observed. The examination revealed the an increased percentage of breaks in lymph node cells of primary disease and the existence of nonrandom change, derivative chromosome 11, which occurred in structural variability in all thre lymphomas studied. The aberration involving chromosome 11 was evaluated as the addition of unknown material at chromosome band 11q11 or as a duplication or triplication of segment 11q12--q23. If this structural aberration was not found, the excessive derivative chromosome 11 or translocation t(11;13) was proved
- to be present. Further, rearrangements of chromosomes 13 and 7 were nonrandom
- chromosome abnormalities revealed in later passages of the lymphomas. The results are in accordance with our previous observations in 14 cases of SD lymphomas that showed nonrandom occurrence of rearrangements concerning 11 and also relatively frequent translocation involving chromosome 13.
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