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Biomedical subjects

F Jelínek

Publications and source records attributed to F Jelínek.

At least 19 recordsLinked to original sources
PubMed2005

Cutaneous papillomatosis in cattle.

Three of four heifers housed together developed multiple cutaneous tumours in the linea alba and on the teats 3 months after the application of plastic muzzle plates with sharp tips to prevent mutual sucking and licking. Fibropapilloma with many koilocytes but few intranuclear inclusions was diagnosed histologically. The dermis showed neoplastic fibroblasts and a structureless intercellular matrix, and nonpurulent vasculitis was also recorded. Immunohistochemical examination with an antibody against L1 papillomavirus antigen demonstrated intranuclear positivity in single cells of the granular and cornified layers and in many mesenchymal cells in the fibrous parts of the tumours. CD3-positive lymphocytes were present in the wall of some blood vessels, and in the dermis and epidermis. Proliferating cell nuclear antigen was detected predominantly in the basal layer of the epidermis and in the superficial dermis. Electron microscopy revealed small intranuclear aggregates of virus particles in an epidermocyte, damage to desmosomes and disorganization of cytokeratin filaments in many epidermocytes. Aggregates of virus particles were revealed also in a fibroblast in the dermis. In blood capillaries of the corium, acute swelling, inflammation and necrosis of the endothelium were observed. By means of the polymerase chain reaction (PCR) and nucleotide DNA sequencing of the PCR product, the virus was identified as bovine papilloma virus type 1 (BPV 1). The presence of this virus in the tissue was further confirmed by in-situ hybridization with a BPV 1 probe.

Animals↗
PubMed2005

Characteristic of two mouse bcr-abl-transformed cell lines: I. General properties of the cells.

In an effort to develop an experimental system suitable for immunological studies in which Bcr-Abl-positive cells are to be used as antigens, we examined the properties of two mouse (Balb/c) established cell lines that express the Bcr-Abl protein and are oncogenic for syngeneic animals. Under standard conditions the two cell lines, viz. Ba-p210 (B210) and 12B1, expressed comparable amounts of the Bcr-Abl protein. However, they differed in a number of characteristics. From the morphological point of view, B210 cells were the more homogeneous, being mainly represented by leukaemic blastic cells with a large number of AgNORs as markers indicating a high proliferative activity. 12B1 cells were more polymorphic and giant cells were detected within their populations. Many 12B1 cells exhibited nuclear segmentation and "band-like" structures. Markers of proliferation were less frequent in 12B1 and the tendency for aging was more pronounced in these cells. The 12B1 cells were slightly more sensitive to imatinib mesylate than B210 cells. In B210 cells, the expression of MHC class I was downregulated, which was not the case with 12B1 cells. Both cell lines induced leukaemia-like disease in mice after intravenous application but, as compared with B210, 12B1 cells were about 100 times more oncogenic and the disease they induced was more aggressive. Moreover, 12B1, but not B210, induced tumours after subcutaneous or intraperitoneal inoculation.

Animals↗
PubMed2005

Characteristics of two mouse bcr-abl-transformed cell lines. II. Pathological lesions induced in mice.

Groups of six BALB/c mice each were intravenously inoculated with lethal doses of Ba-P210 (B210) or 12B1 cells and examined by autopsy, histology, special staining methods, enzyme histochemistry and immunohistochemistry. Clinical symptoms related to neoplasia consisted of a poor nutritional state, anaemia, mild to moderate dehydration and apathy. Paresis was apparent in three mice inoculated with 12B1 cells. Necropsy revealed splenomegaly in all animals. Sporadic haemorrhages in the lungs and enlargement of some lymph nodes were seen in some of the animals. Histological examination showed neoplastic cells in the spleen, in the bone marrow of the sternum, in the lung interstitium and in sinusoids of the liver in all mice. In six of nine brains examined, mild to moderate infiltration by neoplastic cells was observed. In all but two mice mild infiltration of the kidneys was found. The enlargement of lymph nodes was caused by an accumulation of neoplastic cells. The paresis was due to neoplastic infiltration of the vertebra, epidural space and spinal roots. Staining with Sudan black revealed cytoplasmic granules in neoplastic cells; however, the peroxidase reaction was negative. Numerous neoplastic cells disseminated in the red pulp of the spleen were reactive with CD3, CD79beta, CD11b and with neutrophil antibodies. We classified the disease induced by both of the cell lines as acute myeloid undifferentiated leukaemia (AML MO).

Acute Disease↗
PubMed2002

DNA vaccine against Friend erythroleukaemia virus.

Plasmids carrying DNA copies of the gag and env genes of FV, which causes erythroleukaemia in susceptible mouse strains, were prepared. Expression of the cloned genes was confirmed by indirect immunofluorescence in cells transfected in vitro. Immunization experiments were performed in DBA/2 mice. Animals were injected with three doses of plasmid either intramuscularly (100 microg DNA per dose) or intradermally (1 microg DNA per dose); in the latter case, a gene gun was used. The FV type A or P was used as a challenge. The immunization with gag- and env-derived vaccines resulted in protective immunity in a high proportion of mice.

Animals↗
PubMed2001

Metastatic MHC class I-negative mouse cells derived by transformation with human papillomavirus type 16.

In the endeavour to develop a model for studying gene therapy of cancers associated with human papillomaviruses (HPVs), mouse cells were transformed with the HPV type 16 (HPV16) and activated H-ras oncogenes. This was done by cotransfection of plasmid p16HHMo, carrying the HPV16 E6/E7 oncogenes, and plasmid pEJ6.6, carrying the gene coding for human H-ras oncoprotein activated by the G12V mutation, into secondary C57BL/6 mouse kidney cells. An oncogenic cell line, designated MK16/1/IIIABC, was derived. The epithelial origin of the cells was confirmed by their expression of cytokeratins. No MHC class I and class II molecules were detected on the surface of MK16/1/IIIABC cells. Spontaneous metastases were observed in lymphatic nodes and lungs after prolonged growth of MK16/1/IIIABC-induced subcutaneous tumours. Lethally irradiated MK16/1/IIIABC cells induced protection against challenge with 10(5) homologous cells, but not against a higher cell dose (5 x 10(5)). Plasmids p16HHMo and pEJ6.6 were also used for preventive immunization of mice. In comparison with a control group injected with pBR322, they exhibited moderate protection, in terms of prolonged survival, against MK16/1/IIIABC challenge (P < 0.03). These data suggest that MK16/1/IIIABC cells may serve as a model for studying immune reactions against HPV16-associated human tumours.

Animals↗
PubMed2000

Granulomatous inflammation in the tails of mice associated with Mycobacterium chelonae infection.

This report describes a case series of granulomatous inflammation in the tails of seven immunocompromised mice. The disease was associated with Mycobacterium chelonae infection. The source and route of infection remained unclear. Spontaneous infection with M. chelonae has not previously been documented in mice. We conclude that M. chelonae, like in humans, should be considered as a facultative pathogen in laboratory animals, particularly under immunosuppressive conditions.

Animals↗
PubMed1999

Microelectronic sensors for measurement of electromagnetic fields of living cells and experimental results.

Microelectronic sensors are used for measurements of electromagnetic fields generated by synchronized cultures of yeast cells. Cold sensitive mutant tub2-401 of Saccharomyces cerevisiae is used. The measured electromagnetic signals in the frequency range from 8 to 9 MHz are compared with evolution of the reassembled microtubules. The detected signals peak in the time interval 25-30 min and 45-60 min after the release of the cells from the restrictive to the permissive temperature. The first maximum corresponds to the stage when the mitotic spindle is formed and binds chromatids. The second maximum is measured when the processes of anaphase A and of anaphase B take place.

Biosensing Techniques↗
PubMed1999

Artificial emboli based on poly(2-hydroxyethyl methacrylate) particles in animal experiments.

Spherical poly(2-hydroxyethyl methacrylate) particles 0.4-0.6 mm in diameter prepared by suspension polymerization were used for embolization of the internal thoracic artery in ten dogs and the renal artery in two dogs. No signs of toxic or irritating effect of poly(HEMA), either on the artery wall, or surrounding tissues were found in any animal in intervals of observation lasting two weeks, three months or one year. Possible neocapillarity, the presence of fibrous bundles among the particles of poly(HEMA) and, eventually, their slow degradation, were symptomatic of reparative processes.

Angiography↗
PubMed1997

Expression of the proliferating cell nuclear antigen (PCNA) in the rat thyroid gland after exposure to bromide.

Analysis of expression of the proliferating cell nuclear antigen (PCNA) was used to determine the presumed hyperplastic character of morphological changes in the rat thyroid evoked by bromide administration. Male rats fed by a standard diet with determined iodine and bromine content were given potassium bromide. Control animals received no bromide. Experimental animals were given 10, 50 or 100 mg Br- per 11 drinking water for 16 and 66 days, or 100, 200, 400 mg Br-/l drinking water for 133 days. The thyroids of treated animals showed activation of growth of the epithelial follicular component as well as diffuse and focal microfollicular rearrangement of the parenchyma with higher follicular cells accompanied by a decrease of the amount of colloid even at low bromine concentrations (10-100 mg Br-/l drinking water). Using the PCNA-LI index (PCNA-positive nuclei.100/total number of follicular cell nuclei in the section), immunohistochemical analysis of PCNA in the nuclei of the follicular cells was carried out in parrafin sections. The index was significantly higher in bromide exposed animals (P < 0.01) and correlated well with the histological changes, with bromide concentration and with a increased mitotic activity of the follicular cells. PCNA analysis showed that morphological changes resembling a parenchymatic goitre reflect a microfollicular rearrangement of the thyroid of rats exposed to bromide and have the character of hyperplasia owing to the increased mitotic activity of the follicular epithelium.

Animals↗
PubMed1997

Fungus Paecilomyces: a new agent in laboratory animals.

The fungus Paecilomyces has not yet been considered a health problem in laboratory animals. However, this agent known as a 'spoiler' of fruit beverages and other foodstuffs is an opportunistic pathogen especially in immunocompromised humans. Since 1985, we have isolated Paecilomyces, most probably P. variotti, from six laboratory animal species, mainly rats. In about 90% of cases the organism was localized in the respiratory tract and there are some other findings favouring the hypothesis of an airborne infection. During this long observation period no consequences for the health of rats in one closed 'infected' SPF breeding unit (A) could be observed. In a controlled histological study on five infected rats, no lesions attributable to this mycotic agent could be detected. However, a self-limiting spontaneous outbreak of papular skin lesions associated with Paecilomyces was observed in a breeding colony (F) of hairless mice. The role of this fungus in an acute outbreak of respiratory signs in another colony of conventional rats (B) was considered to be secondary. Bearing in mind its occasionally harmful role in humans, relatively high resistance to disinfectants and toxigenicity, this new agent should be monitored and considered a potential health risk for laboratory animals.

Animals↗
PubMed1996

Lack of a beneficial effect of PD123319, an AT2-angiotensin receptor antagonist, on the course of ablation nephropathy in the rat.

Since angiotensin II (ANGII) AT1-receptor antagonists have been shown to possess a beneficial effect on the course of ablation nephropathy, and since the possibility that AT2-receptors are also involved could not be ruled out, the effect of the AT1 antagonist, losartan (L), on the course of ablation nephropathy was compared wit that of PD123319 (PD), an AT2 antagonist. Wistar rats underwent surgical ablation of 5/6 of their renal parenchyma (5/6NX) and for the next 8 weeks were treated with either L alone (5 mg/kg/day), or with L + PD (10 mg/kg/day) or with PD alone. The drugs were administered in drinking water and rats drinking pure water served as controls. Whereas in both groups drinking L the survival rate was 100%, it was only 60% in controls and 66.6% in PD (no significant difference). The rats drinking L have a lower blood pressure, proteinuria and glomerulosclerosis score, and higher creatinine clearance than control and PD rats, again with no difference between these two. Cardiac and kidney remnant hypertrophy was completely abolished in both L groups, whereas it was distinctly present in the other 2 groups without a difference between them. Plasma renin activity was elevated only in both L groups. In conclusion, the beneficial effect of the AT1-receptor blocker L was again confirmed. AT2 receptors are obviously not involved in the detrimental effect of ANGII on the course of ablation nephropathy.

Angiotensin Receptor Antagonists↗
PubMed1996

Changes of glycid composition and binding of some lectins in the caecum of rabbits with experimentally induced enterotoxaemia.

In the goblet cells in the caecum of control rabbits only sialo- and sulphomucins were produced and the same glycoproteins were in the brush border of the surface epithelium. By enterotoxaemia there was a mixture of both acid and neutral glycids or mixed ones in some goblet cells. In lumina of the crypts and on surface of the mucosa, the neutral mucins were predominantly present. By enterotoxaemia binding of soybean agglutinin (SBA) and Ricinus communis agglutinin I (RCA I) in the brush border and in the Golgi apparatus was diminished or abolished. The binding of wheat germ agglutinin (WGA) was reduced to some goblet cells or surface of the crypts. Binding of concanavalin agglutinin (ConA) was not changed in comparison with control rabbits. These results showed that enterotoxaemia in rabbits is related, among other things, also to changes in mucosal glycid composition, binding of SBA and RCA I lectins and these changes precede morphologically apparent alteration.

Animals↗
PubMed1996

Medulloepithelioma in a cat.

Castrated male of European cat, bastard, 16 month-old suffered from a grayish-pink tumour in the anterior chamber of the right eyeball in the course of last six months. After enucleation, the eye was examined by histology, immunohistochemistry (NSE, NPF, S-100 protein) and electronmicroscopy. The tumour was classified as malignant medulloepithelioma. Existence of neuroblastoma in animals and frequency of neuroblastoma and medulloepithelioma in humans and animals is discussed.

Animals↗
PubMed1995

Immunosuppression and feeding success of Ixodes ricinus nymphs on BALB/c mice.

The effect of repeated infestations of Ixodes ricinus (L.) nymphs on BALB/c mice was studied. Four successive infectations resulted in an increase of tick feeding success. Tick yield and mean engorged weight increased and the length of the feeding period was reduced significantly (P < 0.05-0.01). The increase of specific anti-tick antibodies was not significant (P > 0.05). The blastogenic response of spleen lymphocytes to T-cell mitogens (Con A and PHA-P) was unimpaired or slightly enhanced, whereas the response to B-cell activators (LPS and PWM) was suppressed, as was the total antibody generation in vitro. The numbers of mast cells in murine skin at the tick attachment sites slightly decreased during the third infestation. The suppression of B-cell competence and of antibody generation, together with decrease of skin mast cell numbers in tick attachment sits, are considered to be responsible for enhancement of tick feeding success.

Animals↗
PubMed1995

[The effect of Tenziomin on function, morphology and lectin binding in rat kidney remnants after experimental subtotal nephrectomy].

Captopril (Tenziomin) treated rats after subtotal (5/6) nephrectomy showed conspicuously better function of kidney tissue remnants than untreated animals. Histology was the same in both groups--focal glomerulosclerosis, anisocytosis and anisokaryosis of tubular epithelial cells, hyperplasia of proximal tubuli. Proteinuria was substantially lower in treated animals. Lectin histochemistry showed differences between superficial and juxtamedullary nephrons in glycoprotein contents and function. An important finding was selective binding of WGA lectin in brush border of proximal convoluted tubuli of juxtamedullary nephrons. Differences in lectin binding between nephrectomized and intact control animals were rather quantitative than qualitative.

Animals↗
PubMed1994

[The effect of antibiotics on the development of enterotoxemia-- experimental study].

When testing antibiotics in rabbits Dalacin was shown to be the most effective in inducing enterotoxaemia in rabbits. Autopsy disclosed signs of enterotoxaemia even in some animals without previous symptoms. Histopathological lesions were found even in intestines macroscopically normal. Experiments proved that after application of tested antibiotics spread through intestinal mucosa and produced a loss of microbial balance. Rabbit is to be considered suitable for modelling antibiotic-induced enterotoxaemia.

Animals↗