Biomedical subjects

J Kanka

Publications and source records attributed to J Kanka.

At least 19 recordsLinked to original sources

PubMed2000

Culture of bovine oocytes from small antral follicles in meiosis-inhibiting medium with butyrolactone I: RNA synthesis, nucleolar morphology and meiotic competence.

Bovine oocytes originated from follicles of two different size categories (medium (M), 3-6 mm and small (S), 1-2 mm) were cultured for 24 and 70 h, respectively, in a meiosis-inhibiting medium (MIM) supplemented with 100 microM butyrolactone I (BL I). At the end of culture, cumulus oocyte complexes (COC) from M and S follicles were labeled by 3H-uridine for 30 min. The autoradiography (ARG) of semi-thin sections of COC showed the labeling of the germinal vesicles (GV) as: (1) The COC of the M category labeled immediately after isolation from follicles showed only weak labeling (+) of the GV. The COC of the S category labeled immediately after their isolation showed mostly intensive labeling (4+,3+) of the GV. (2) When the COC were labeled after 24 and 70 h of culture in MIM, no labeling was observed in the M category. The S category of oocytes showed the slightly decreased labeling (3+,2+) after 24 h and negligible labeling after 70 h of culture. The pattern of very intensive labeling of granulosa cell nuclei of all mentioned groups was practically not changed during the whole 70 h period of culture in both categories. The nucleolar ultrastructure of S category oocytes revealed time dependent changes from the reticular fibrillogranular structure present in freshly isolated oocytes. The several fibrillar centers before the culture changed to the fibrillogranular appearance with few large and a number of small vacuoles and an exclusively fibrillar area after 24 h of culture. Finally, nucleoli acquired a mostly exclusively fibrillar structure with one large fibrillar center after 70 h of culture. In the second experiment, the meiotic maturation of COC of S category was inhibited in MIM for 48 h. The subsequent 24 h culture in a medium with BOS and gonadotropins resulted in 81.0% oocytes matured to metaphase II (M II). Only 27.1 and 11.3% of the control S oocytes cultured in a medium, with BOS and gonadotropins directly after isolation, reached M II after 48 or 72 h of culture, respectively. The two-step culture increased significantly the meiotic competence of cattle oocytes isolated from small antral follicles.

4-Butyrolactone↗

PubMed2000

[Papillomaviruses and human tumors].

The report summarizes the main results obtained in the course of our research project. The results of immunological and epidemiological studies provide further proofs that human papillomaviruses (HPV) are the etiological agents in cervical neoplasia. In addition, they raise hopes that immunological methods may be utilized in diagnostics of cervical cancer and for monitoring the clinical course of this disease in the near future. Since the etiological relationship between HPV and cervical carcinoma seems to be proven beyond reasonable doubt, the development of prophylactic and therapeutic vaccines has become the dominant of the contemporary HPV reseach. For studying immune reactions against HPV-induced tumours we developed a model of HPV16-transformed rodent cells.

Female↗

PubMed1999

Prospective study on cervical neoplasia IV. Presence of HPV antibodies.

Sera collected in the course of a prospective study carried out in Prague in 1975-1983 were assayed for the presence of human papillomavirus (HPV) antibodies. Women with cervical neoplasia proven by biopsy at enrollment possessed antibodies to peptides derived from E2, E4 and E7 proteins of HPV16 and to virus-like particles (VLPs) of HPV16, -18 and -33 significantly more frequently than matched controls. Women without cervical neoplasia at enrollment who developed the disease in the course of the study differed from matched controls by a higher prevalence of antibodies against VLPs of HPV16 and -18 but not against early antigens of HPV16. In 19 of the latter subjects, paired serum specimens were tested, the first samples having been taken at enrollment and the second at diagnosis. Development of the disease was associated with seroconversion from negativity to positivity to at least one HPV antigen in 11 (57.9%) women.

Adult↗

PubMed1999

Human papillomavirus genotype spectrum in Czech women: correlation of HPV DNA presence with antibodies against HPV-16, 18, and 33 virus-like particles.

Because the biological spectrum of human papillomavirus (HPV) genotypes present in cervical cancer lesions varies according to the geographical region studied, and because little genotype information is available for Central and Eastern European countries, we studied the endemic HPV-genotype spectrum in cervical samples collected from women visiting gynaecological departments of selected hospitals in the Czech Republic. In a series of 389 samples, 171 (44.0%) were positive for HPV DNA using a consensus-primer polymerase chain reaction (PCR). Genotyping of the HPV PCR products was done using dot-blot hybridisation with type-specific oligonucleotide probes and thermocycle DNA sequencing. Twenty-two different HPV types were detected, HPV-16 being the most prevalent type irrespective of severity of the lesions (55.0%). Multiple HPV types were found in 16.4% of our HPV-DNA-positive samples. The prevalence of HPV infection was 23.0% in women with normal findings and 59.4% in patients with cervical neoplasia, and increased significantly with the severity of the disease: 52.9% in low-grade lesions, 58.0% in high-grade lesions, and 73.5% in cervical carcinomas (P for trend < .00001). In the sera of 191 subjects, 89 with normal findings and 102 with different forms of cervical neoplasia, the prevalence of HPV-specific IgG antibodies was tested by an enzyme-linked immunosorbent assay (ELISA) using virus-like particles (VLPs) of HPV-16, -18, and -33. Antibodies were significantly more prevalent in HPV-DNA-positive than in HPV-DNA-negative women and there was no association with age. In agreement with the results of HPV genotyping, antibodies reactive with HPV-16 VLPs were the most frequent and, moreover, their prevalence increased with the cervical lesion severity. About half of the subjects with smears in which either HPV-16 or HPV-33 DNA had been detected possessed antibodies reactive with homotypic VLPs. With HPV-18-DNA-positive subjects, however, fewer than 25% displayed homotypic antibodies. In general, subjects older than 30 years of age had antibodies reactive to HPV-specific VLPs more often than subjects younger than 30 years of age. In women with benign findings, the seropositivity to HPV-16, -18, and -33 VLPs increased with age, whereas in women with cervical neoplasia the seropositivity decreased with age.

Adult↗

PubMed1999

Nucleolar ultrastructure in bovine nuclear transfer embryos.

Nuclear transfer experiments in mammals have attempted to reprogram a donor nucleus to a state equivalent to the zygotic one. Reprogramming of the donor nucleus is, among other features, indicated by a synthesis of ribosomal RNA (rRNA). The initiation of rRNA synthesis is simultaneously reflected in nuclear morphology as a transformation of the nucleolus precursor body into a functional rRNA synthesising nucleolus with a characteristic ultrastructure. We examined nucleolar ultrastructure in bovine in vitro produced (control) embryos and in nuclear transfer embryos reconstructed from a MII phase (nonactivated) or S phase (activated) cytoplasts. Control embryos were fixed at the two-, four-, early eight- and late eight-cell stages; nuclear transfer embryos were fixed at 1 and 3 hr post fusion and at the two-, four-, and eight-cell stages. Control embryos possessed a nucleolar precursor body throughout all three cell cycles. In the eight-cell stage embryo, a primary vacuole appeared as an electron lucid area originating in the centre of the nucleolar precursor body. In nuclear transfer embryos reconstructed from nonactivated cytoplasts, the nuclear envelope was fragmented or completely broken down at 1 hr after fusion and, by 3 hr after fusion, it was restored again. At this time, the reticulated fibrillo-granular nucleolus had an almost round shape. The nucleolar precursor body seen in the two-cell stage nuclear transfer embryos consisted of intermingled filamentous components and secondary vacuoles. A nucleolar precursor body typical for the two-cell stage control embryos was never observed. None of the reconstructed embryos of this group reached the eight-cell stage. Nuclear transfer embryos reconstructed from activated cytoplasts, in contrast, exhibited a complete nuclear envelope at all time intervals after fusion. In the two-cell stage nuclear transfer embryo, the originally reticulated nucleolus of the donor blastomere had changed into a typical nucleolar precursor body consisting of a homogeneous fibrillar structure. A primary vacuole appeared in the four-cell stage nuclear transfer embryos, which was one cell cycle earlier than in control embryos. Only nuclear transfer embryos reconstructed from activated cytoplasts underwent complete remodelling of the nucleolus. The reorganisation of the donor nucleolar architecture into a functionally active nucleolus was observed as early as in the four-cell stage nuclear transfer embryo. These ultrastructural observations were correlated with our autoradiographic data on the initiation of RNA synthesis in nuclear transfer embryos.

Animals↗

PubMed1997

Time course of pronuclear deoxyribonucleic acid synthesis in parthenogenetically activated bovine oocytes.

The progress of pronuclear DNA synthesis was monitored by the radioactive precursor 3H-thymidine during the first cell cycle of parthenogenetically activated bovine oocytes. Bovine oocytes were exposed to Ca2+ ionophore A23187 at 24, 30, or 36 h after the onset of in vitro maturation. Young 24-h oocytes were subsequently cultured for 6 h in the protein synthesis inhibitor, cycloheximide (CHX), to ensure similar rates of activation (96-100%) and pronuclear formation (93-97%) among all groups of oocytes. Subsequent autoradiographic experiments revealed a slightly, but not significantly, accelerated start of DNA synthesis in aged (36 h) oocytes. Maximum levels of DNA labeling were reached within 4 h regardless of oocyte maturation age and persisted for 4 h in 30-h oocytes compared to 2 h in 36-h and 24-h oocytes. The period of DNA synthesis lasted for a total of 12-14 h in all groups of oocytes, and the duration of S-phase was less than 6 h. Since rates of pronuclear formation (58%) and labeling (58%) corresponded to each other, it is argued that only a fully developed pronucleus can synthesize DNA. Oocyte labeling performed in the presence of CHX revealed the capability of CHX to inhibit DNA synthesis up to 8 h postactivation. Removal of CHX by washing when the majority (94%) of oocytes had formed a fully developed pronucleus (at 8 h postactivation) led to the synchronous start of DNA synthesis within 1.5-2 h post-CHX culture. This concomitantly defined the time required for synthesis of vital proteins needed for the entry into S-phase and/or DNA replication. The prolonged exposure of activated oocytes to CHX (10-12 h) negatively affected the pattern of DNA synthesis. The start of DNA synthesis was postponed and reduced pronuclear labeling was observed. In addition, CHX-treated oocytes often exhibited a characteristic punctate pattern of pronuclear labeling in which silver grains were accumulated into clusters. In conclusion, the present results provide knowledge about timing and a possible synchronization of DNA synthesis in parthenogenetically activated bovine oocytes.

Animals↗

PubMed1996

Oocyte-specific modulation of female pronuclear development in mice.

Cell fusion experiments were undertaken to determine both whether oocytes possess, in a stage-specific manner, suppressors of pronuclear development and whether these factors could be used to modulate female pronuclear development. The fusion of telophase II eggs obtained 2 hr after activation (A2 eggs) to germinal vesicle (GV)-staged oocytes (GV x A2) suppresses female pronuclear development. The cytoplasm of GV x A2 heterokaryons contains, at 10 hr postfusion, a micropronucleus and a GV which is significantly larger (approximately x1.6) than normal. Fusion of early pronucleate eggs (3 hr postactivation, A3) to GV-staged oocytes (GV x A3) results in the formation of a retarded half-sized pronucleus and a slightly enlarged (approximately x1.2) GV at 10 hr postactivation. Normal pronuclear formation occurs when eggs at 4 hr postactivation (A4) are fused to GV oocytes (GV x A4). Although pronuclear size is suppressed in heterokaryons formed when GV-staged oocytes are fused to eggs activated 2-3 hr earlier (A2 or A3 stage), entry into S-phase and DNA synthesis is not inhibited even in the micropronuclei. Meiotic progression in the oocyte germinal vesicle is arrested after fusion to activated eggs throughout the period during which the pronucleus is undergoing G1 and S-phase. However, at the end of S-phase in the pronucleate partner, germinal vesicle breakdown occurs, cell cycle progression is accelerated, and both nuclei reach M-phase by 12 hr postactivation. That suppressors of pronuclear development are found only in GV (G2)-staged oocytes, and not in mitotic cells at the same cell cycle stage, was demonstrated by fusing G2-staged blastomeres to A2-staged eggs (G2 mitotic x A2). By contrast to the micropronuclei formed in GV x A2 heterokaryons, normal pronuclear development occurred in G2 mitotic x A2 heterokaryons. Our results show that suppressor activity, present only in GV oocytes, restricts female pronuclear development, but only in the first 3 hr after activation. We propose to use the ability to modulate either female (this study) or male pronuclear formation in studies (i) on imprinting and (ii) on the developmental consequences of early asynchrony between male and female pronuclear development.

Animals↗

PubMed1996

Transcriptional activity and nucleolar ultrastructure of embryonic rabbit nuclei after transplantation to enucleated oocytes.

Changes in the level of transcriptional activity in 32-cell stage morula nuclei were studied after blastomere electrofusion to enucleated oocytes. Nuclear transplant recipients were pulse labelled with 3H-uridine during cultivation in vitro, embryos were then fixed and processed for autoradiography and electron microscopy. Transcriptional activity substantially decreased after 4.5 hr and was completely inhibited at last 15 hr after fusion. Transcription resumed thereafter in two-cell stage embryos and could be detected in both nuclei from 70% of the embryos analyzed. Transcription activity rapidly increased at the eight 16-cell stages, reaching the level typical for 32-cell stage nuclei used for the transfer. Changes in nucleolar ultrastructure after the nuclear transfer reflected the inhibition and subsequent reactivation of rRNA transcription. Nucleoli of 32-cell embryos had a typical structure of active nucleoli; many fibrillar centers surrounded and interconnected by threads of the dense fibrillar component and embedded in the granular component. Six hours following nuclear transplantation, these nucleoli underwent drastic changes including loss of granular material, collapse of nucleolar structure, and segregation of nucleolar components. Following the first cleavage, segregated fibrillar components of nucleoli manifested a complete inhibition of nucleolar transcription. Ribosomal RNA transcription was restored at the eight-cell stage and the sequence of ultrastructural changes was similar to that of the normal development. However, at the 32-cell stage, excessive extrusion of pre-ribosomal particles in the cytoplasm occurred, suggesting a possible alteration in regulating mechanisms of ribosome delivery. These results show that after fusion with enucleated metaphase II cytoplasm and subsequent activation, transcription is inhibited in donor embryonic nuclei and progressively increases again during cleavage; almost as in normal embryos. Migration of ribosomes into cytoplasm appears more intense in 32-cell stage reconstituted embryos but this does not seem to inhibit blastocyst building.

Animals↗

PubMed1996

Nuclear transplantation of ectodermal cells in pig oocytes: ultrastructure and radiography.

This study investigated the changes in nucleolar fine structure and the synthesis of both heterogeneous nuclear RNA (hnRNA) and ribosomal RNA (rRNA) in pig reconstructed embryos obtained by electrofusion of a single pig ectodermal cell to an enucleated metaphase-II oocyte. The nucleolar morphological changes and the pattern of transcription were examined in the ectodermal cells before fusion and in the nuclear transfer reconstructed embryos 16-18 hr after fusion. Before fusion the ectodermal cells exhibited a reticulated nucleolus with active RNA synthesis. In the reconstructed embryos, modifications of the nucleolar structure were observed, as assessed by the presence of either round-shaped, compact, dense nucleolar precursor bodies, or reticulated nucleoli. However, in both cases there was no RNA synthesis. Blebbing activity of the nuclear envelope was not observed. These results indicate that the nucleus of pig ectodermal cells exhibited either a complete or an incomplete remodelling when transferred to an enucleated metaphase-II oocyte, with no detectable RNA synthesis. Cell-cycle synchronization of ectodermal cell donor nuclei may play an important role in nuclear reprogramming after fusion.

Animals↗

PubMed1996

Influence of recipient cytoplasm cell stage on transcription in bovine nucleus transfer embryos.

Nucleus transfer for the production of multiple embryos derived from a donor embryo relies upon the reprogramming of the donor nucleus so that it behaves similar to a zygotic nucleus. One indication of nucleus reprogramming is the RNA synthetic activity. In normal bovine embryogenesis, the embryo relies upon maternally derived RNA transcripts up to the 8-cell stage, at which time it begins to transcribe its own RNA. In this experiment, RNA synthesis was detected in nucleus transfer embryos (NTE) and control embryos by pulsing with 3H-uridine, fixation, and autoradiography on semithin sections. NTE were produced using either a MII phase (nonactivated) cytoplasts at 32 hr of maturation or S-phase (activated) cytoplasts activated with calcium ionophore A23187 and cycloheximide treatment approximately 8 hr prior to fusion with a blastomere from an in-vitro-produced morula stage embryo at 32 hr of maturation. Control in-vitro-produced embryos were 3H-uridine-labelled and fixed at the 2-, 4-, early 8-, and late 8-cell stages. NTE were similarly prepared at 1, 3, and 20 hr postfusion and at the 2-, 4-, and 8-cell stages. In the control embryos, RNA synthesis was absent in the 2-, 4-, and early 8-cell stages, whereas in all late 8-cell stages, it was present. In NTE from nonactivated (MII phase) cytoplasts, there was a sharp decline in RNA synthesis at 1 hr and 3 hr after fusion and a total absence by 20 hr after fusion. In contrast, NTE from activated (S phase) cytoplasts exhibited continued high levels of RNA synthesis at 1 hr and moderate levels at 3 hr after fusion, although it had ceased by 20 hr after fusion. In all NTE (activated and nonactivated cytoplasts), there was no RNA synthesis seen at the 2-cell stage. However, at the 4-cell stage, weak RNA synthesis was seen in all NTE from activated cytoplasts, whereas none was observed in those from MII nonactivated cytoplasts. At the 8-cell stage, nearly all NTE from S-phase cytoplasts showed weak to moderate levels of RNA synthesis. We conclude that the nucleus reprogramming differs between NTE reconstructed from activated and nonactivated cytoplast with the former undergoing a slower cessation of RNA synthesis after fusion and earlier resumption of RNA synthesis, occurring as early as the 4-cell stage.

Animals↗

PubMed1996

[Interleukin-6 and acute phase reactants in the diagnosis of ovarian carcinoma].

In 115 women (healthy controls and patients with benign and malignant gynaecological tumors) interleukin-6 was determined in blood plasma with the aim to decide whether elevated IL-6 levels may be used as a marker of ovarian carcinoma. In spite of statistically significantly increased IL-6 levels the authors do not regard at present the IL-6 values as a useful marker of ovarian carcinoma for two reasons: first, until now it is not decided whether elevated IL-6 values originate only from the cells of epithelial ovarian carcinoma or if they are also produced by tumour-associated macrophages or both and second: in a large number of cases (both controls and patients with malignant tumors) no IL-6 levels in blood plasma could be detected. For these reasons it seems to be more convenient (even economically) to determine in suspected cases and after exclusion of any inflammatory process the levels of prealbumin and transferrin. Significantly decreased levels of both have a high value of primary sensitivity (66% and 87% resp.).

Acute-Phase Proteins↗

PubMed1996

Nuclear transplantation in pigs: M-phase karyoplast to M-phase cytoplast fusion.

Porcine embryonic fibroblasts in M-phase were isolated from confluent cultures by selective detachment and fused to homologous metaphase II enucleated oocytes. The fusion products were analysed by light and electron microscopy (EM). The fusion treatment, per se, did not induce the disappearance of the maturation promoting factor (MPF) in the cloned embryos and the transferred chromatin remained condensed for up to 10 h. Spontaneous decondensation started after this time and, at about 20 h post-induction of fusion, a single large nucleus was present in the cytoplasm. The prolonged exposure of introduced chromatin to MPF resulted in a total morphological remodelling as assessed by the nucleolar morphology observed by EM in all the specimens.

Animals↗

PubMed1996

[Bilateral adrenocortical adenomas and the pheochromocytoma syndrome].

A 43-year-old man with clinical signs of pheochromocytoma and adrenal adrenal enlargement underwent adrenalectomy. Bilateral adrenocortical adenomas accompanied by a pressure atrophy of surrounding cortex and normal adrenal medulla were found. The tumours exhibited neither immunohistochemical nor ultrastructural signs of medullar differentiation. As the clinical symptoms of pheochromocytoma slowly disappeared during the 18 month-postoperative period we consider the local tumour activity most probably responsible for the pseudopheochromocytoma symptomatology.

Adrenal Cortex Neoplasms↗

PubMed1995

Response of avian nuclei to mammalian maturation promoting factor (MPF).

Chicken blastodermal cells (stage X) were fused to mouse enucleated oocytes with either no or high maturation promoting factor (MPF) activity. High MPF levels always induced premature chromosome condensation (PCC) irrespective of the number of nuclei fused to a single oocyte. When a single blastodermal cell was fused to a single oocyte without MPF activity the nucleus remained intact for up to 3 h and thereafter underwent PCC. A quite different situation was observed after multiple fusion of several blastodermal cells to a single oocyte without MPF activity. Here, the transplanted nuclei remained intact even after prolonged culture but underwent extensive swelling. DNA synthesis was detected in almost all unfused blastodermal cells. However, after the fusion of several blastodermal cells to a single oocyte no DNA synthesis could be detected. These results provide further evidence that MPF is the universal cell-cycle regulator in the animal kingdom. Its activity is blocked (or neutralised) after fusion to several S-phase cells. Interestingly, our results further suggest that DNA synthesis is suppressed in meiotic cytoplasm even in the presence of an intact nuclear envelope.

Animals↗

PubMed1995

Chromosome condensation activity (CCA) in bisected C57BL/6JxCBA mouse oocytes.

Chromosome condensation activity (CCA) has been analysed in C57BL/6Jx CBA mouse oocytes bisected (i) shortly after germinal vesicle breakdown (GVBD), (ii) in metaphase I (MI) and (iii) in metaphase II (MII) into two equal halves (nucleated, enucleated) which were thereafter fused to S- or G2-phase 4-cell-stage mouse blastomeres. In nucleated halves, premature chromosome condensation (PCC) in transplanted nuclei was always induced irrespective of the cell cycle stage of the blastomere, whereas in enucleated halves only G2 nuclei underwent PCC after transplantation. Premature chromosome condensation in S-phase nuclei was induced only in enucleated halves produced shortly after GVBD. Although S-phase nuclei transplanted to MI or MII enucleated halves remained intact, their capacity to synthesize DNA was invariably suppressed. When spindles were destroyed by preincubation of the oocytes in colcemid before bisection, both nucleated and enucleated halves produced at MI or MII induced PCC of both G2- or S-phase nuclei. These results demonstrate that chromosome condensation activity in mammalian oocytes is compartmentalized rather than uniformly distributed across the cell, and that the enucleation of mammalian oocytes before nuclear transplantation may, under some conditions, influence the levels of CCA and subsequent response of introduced nuclei to cytoplasmic factors.

Animals↗

PubMed1995

[Potential carcinogenic factors in cervical intraepithelial neoplasia].

In a group of 22 women with cervical intraepithelial neoplasia and carcinoma of the cervix uteri and in a control group of 37 healthy women, a number of anamnestic and objective data about factors influencing these women and about consequences of such influence were analysed. Statistically significant differences between patients and controls were found in the character of work performed (physical vs. intellectual, p = 0.0312), the presence of stressing factors at the workplace (p = 0.02), a higher number of consumed meals per day in the control group (p = 0.0009), daily consumption of beer in a higher percentage of patients (p = 0.0015), the frequency of sexual intercourse in the last 2-3 months before the diagnosis of disease or examination (higher in controls, p = 0.0164) and subjective rating of sexual life in the fourth decade (better rating in controls, p = 0.0005). No differences were found between patients and controls in the number of sexual partners, the presence of antibodies against HSV-2 and other factors. According to data presented and data in the literature, external environment, some of the characteristics of sexual life and particularly infection with certain types of papillomaviruses have a certain influence on the development of cervical neoplasias.

Female↗

PubMed1994

A reversible block at the G1/S border during cell cycle progression of mouse embryos.

Late 2-cell stage mouse embryos were cultured in M-199 plus 100 micrograms/ml Na pyruvate 25 micrograms/ml gentamycin and 0.3% BSA with or without mimosine (200 microM, 150 microM, 100 microM and 50 microM) for a short (4-5 h) or long (18-20 h) culture period; after drug removal subsequent embryo development was evaluated. Late 2-cell stage mouse embryos treated with mimosine were blocked at the 4-cell stage. Autoradiographic studies show that mimosine inhibits cell cycle progression in mouse embryos at the G1/S boundary. The onset of DNA replication occurs within 15 min of releasing the embryos from mimosine block. Embryos pretreated with mimosine at 200 microM and 150 microM for 4-5 h progress after 3-4 days in culture to hatched blastocyst (71% and 79%, respectively) compared with control (90%). However a longer pretreatment (18-20 h) with mimosine at 200 microM was significantly detrimental to the subsequent developmental progression to hatched blastocyst (2% vs 81%, p < or = 0.05); the proportion of degenerated embryos was significantly increased with mimosine at 200 microM and 150 microM compared with control (57% and 28% vs 4%, p < or = 0.05) after 3-4 days in culture. Preliminary studies with mimosine treatment at 100 microM and 50 microM for 18-20 h show that 70% and 37% of the embryos were blocked at 4-cell stage, respectively. These results indicate that mimosine inhibits cell cycle progress in mouse embryos at the G1/S border and thus induces a reversible arrest in a dose- and time-dependent manner.

Animals↗

PubMed1994

[Correlation of clinical and virologic diagnosis of cervical infection with human papillomaviruses].

The presented investigation is concerned with contemporary diagnostic possibilities of HPV Infection of the Cervix. The authors present the results of virological examinations of 228 female patients in the Centre for Oncological Prevention. The examination was made by hybridization techniques, using probes specific for HPV 6, 11, 16 and 18 and by serological methods where IgG antibodies were assessed against synthetic peptides, corresponding to several HPV epitopes, as antigens. 156 women (68.4%) were virologically positive, 72 (31.6%) were negative. Subsequently the authors investigated the diagnostic accuracy of HPV changes of the cervix by clinical methods, i.e. colposcopy and cytology, as compared with virological methods. On colposcopic examination uncertain--i.e. insignificant--results were recorded in 24.6%, on cytological examination in 19.7%. In patients where these methods gave unequivocal results (either + or-) a correct forecast of the presence of HPV during colposcopic examination was recorded in 71.1%, in cytological examinations in 66.9%. At least one of the clinical methods assessing papilloma virus infection was prognostically correct in 90.4%. From the investigation ensures that prebioptic methods provide the clinician with relatively reliable information on the presence of HPV infection and enable him to select a therapeutic and dispensarization procedure adequate to the finding. However, they cannot replace virological examination among other reasons also because they cannot assess the HPV type.

Colposcopy↗