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V Toder

Publications and source records attributed to V Toder.

At least 37 records · Page 2Linked to original sources
PubMed1999

TGF beta 2 mRNA expression and pregnancy failure in mice.

PROBLEM: We describe here a pattern of transforming growth factor (TGF) beta2 mRNA expression at the fetomaternal interface in mice with high rate of resorptions as well as its expression following maternal immunopotentiation. METHOD OF STUDY: TGF beta 2 mRNA expression was evaluated in the uteroplacental units of mice with spontaneous (CBA/J x DBA/2J mouse combination) or cyclophosphamide (CP)-induced pregnancy loss. The effect of immunopotentiation on TGF beta 2 mRNA expression was determined in CP-treated females who underwent nonspecific immunostimulation with xenogeneic (rat) leukocytes. A quantitative analysis of TGF beta 2 mRNA level was performed using RNase protection assay. Distribution of TGF beta 2 mRNA transcripts at the fetomaternal interface was studied by in situ hybridization analysis. RESULTS: RNase protection analysis revealed four TGF beta 2 specific mRNA forms (330, 270, 230, and 170 bp) in the uteroplacental units of mice with either normal or decreased reproductive performance. A significant decrease (about 50%) in the level of TGF beta 2 mRNA was registered in the uteroplacental unit of mice with pregnancy loss as compared to the control mice. TGF beta 2 transcripts were abundant in the uterine epithelium and stroma. A specific hybridization signal was detected also in metrial gland cells and it was found to be substantially lower in CP-treated as compared to intact mice. In the resorbing uteroplacental unit, the expression of TGF beta 2 mRNA was completely lost in the uterine epithelium, and the number of TGF beta 2 mRNA-positive metrial gland cells was lower as compared to the control. Immunopotentiation decreased the resorption rate in mice with CP-induced pregnancy loss and caused a dramatic increase in TGF beta 2 mRNA expression: the level of TGF beta 2 mRNA was found to be higher by 2.0-3.2 fold in the uteroplacental unit of immunized as compared to nonimmunized CP-treated mice. CONCLUSIONS: These data suggest that distortion of TGF beta 2 expression at the fetomaternal interface may be associated with pregnancy failure. It seems that beneficial effect of maternal immunostimulation may at least partly be due to the strong increase in TGF beta 2 mRNA expression at the fetomaternal interface.

Abortion, Induced↗
PubMed1999

Cellular events and the pattern of p53 protein expression following cyclophosphamide-initiated cell death in various organs of developing embryo.

This study was aimed at characterizing the temporal patterns of cell responses and p53 protein expression in the limbs, head, and liver of embryos responding to cyclophosphamide (CP)-induced teratogenic insult. ICR murine embryos were examined 24, 48, or 72 h after injection of 40 mg/kg CP on day 12 of pregnancy. The cellular events and temporal pattern of p53 protein expression were determined by FACS analysis and by TUNEL (apoptosis) in the head, limbs, and liver of the embryos. All tested organs showed apoptosis and a significantly decreased proportion of live cells after 24 h. Subsequent events were organ-dependent. In the liver, there were no dysmorphic events at any time and excessive cell death had been almost compensated for by 48 h. Compensation was preceded by G(1) arrest and accompanied by an increased level of p53 protein in surviving cells. Excessive cell death in the head and the limbs resulted in structural anomalies. In the head, there was an increased level of p53 protein and G(1) arrest after 24 h and the number of live cells at 48 h was equal to that seen in earlier samples, despite apoptosis. In the limbs, however, only isolated viable cells were seen by 48 h, but there was no increased level of p53 protein or G(1) arrest. Results of this study suggest that the differential sensitivity of tested organ systems to CP may be associated with differences in cellular events following CP-initiated cell death. They also suggest that the input of p53 in determining the response of these organ systems to CP-induced teratogenic insult may be different. Teratogenesis Carcinog. Mutagen. 19:353-367, 1999.

Animals↗
PubMed1998

TNF-alpha messenger RNA and protein expression in the uteroplacental unit of mice with pregnancy loss.

An elevated expression of TNF-alpha in embryonic microenvironment was found to be associated with postimplantation loss. In this work, we examined the pattern of TNF-alpha expression at both the mRNA and the protein level as well as the distribution of TNF-alpha receptor mRNA in the uteroplacental unit of mice with induced (cyclophosphamide-treated) or spontaneous (CBA/J x DBA/2J mouse combination) pregnancy loss. RNase protection analysis demonstrated an increase in TNF-alpha mRNA expression in the placentae of mice with pregnancy loss compared with that in control mice. TNF-alpha messages were localized to the uterine epithelium and stroma as well as the giant and spongiotrophoblast cells of the placenta. The intensity of the hybridization signal in placentae of mice with pregnancy loss was substantially higher than that in control mice. The up-regulation of TNF-alpha mRNA was accompanied by an increase in the expression of TNF-alpha receptor I mRNA in the same cell populations. The elevation of TNF-alpha production was also demonstrated at the protein level. Western blot analysis showed an increased level of the 18- and 26-kDa TNF-alpha protein species in the uteroplacental unit of mice with pregnancy loss. Immunostaining revealed TNF-alpha-positive leukocytes located in the uterus and placenta. Finally, we found that immunization of mice with cyclophosphamide-induced pregnancy loss while decreasing the resorption rate in these females resulted in a decline in TNF-alpha expression at the fetomaternal interface. These data clearly suggest an involvement of TNF-alpha in pathways leading to both spontaneous and induced placental death.

Abortion, Spontaneous↗
PubMed1998

Ciprofloxacin immunomodulation of experimental antiphospholipid syndrome associated with elevation of interleukin-3 and granulocyte-macrophage colony-stimulating factor expression.

OBJECTIVE: To evaluate the immunomodulatory potential of ciprofloxacin in mice with experimental antiphospholipid syndrome (APS). METHODS: Ciprofloxacin or ceftazidime (control antibiotic) was given to mice with experimentally induced APS. The titers of autoantibodies, levels of cytokines, and number of cytokine-producing cells were determined by enzyme-linked immunosorbent assay. Myeloid progenitor cells were determined by granulocyte-macrophage colony-forming unit, and interleukin-3 (IL-3) messenger RNA (mRNA) was tested by Northern analysis. RESULTS: A decrease in the incidence of pregnancy loss and an improvement in the clinical manifestations of APS were noted in the mice treated with ciprofloxacin, compared with the mice given ceftazidime. The effect of ciprofloxacin was found to be associated with increased serum levels of IL-3 and with increased IL-3 mRNA transcription in the splenocytes. Expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) was documented by elevated titers in the sera and elevated numbers of colony-forming cells in the bone marrow. CONCLUSION: Ciprofloxacin prevents the manifestations of experimental APS. This effect may be associated with increased IL-3 levels and GM-CSF expression.

Adjuvants, Immunologic↗
PubMed1998

Expression of allogeneic MHC class I antigens by transgenic mouse trophoblast does not interfere with the normal course of pregnancy.

Mammalian embryos express paternal histocompatibility antigens which make them potential targets for maternal immune responses. Yet, the histoincompatible fetus survives and develops normally. Down regulation of classical MHC antigen expression by trophoblast cells which are in direct contact with maternal circulation has been repeatedly shown. The trophoblast cells are unable to function properly in antigen presentation and do not induce allogeneic rejection reactions. In the present study we have created transgenic mice that express an allogeneic class I transgene whose transcription is controlled by the transferrin receptor promoter. The expression patterns of the transgene product mice from a single transgenic line were studied in each of the typical placental subpopulations. The allogeneic class I antigen was expressed in the allantoic plate region of the trophoblast, and this expression was not restricted to the endothelial region but extended also to the spongiotrophoblast, as well as the major blood vessels and in the endodermal sinuses. In contrast to the normal class I expression, prominent levels of allogeneic H-2 antigens were detected in the labyrinthine trophoblast. The fetal resorption rate in females mated with these transgenic males was not higher then the normal rate, and the embryos survived and developed normally. These data imply that the unusual expression of allogeneic class I antigens in certain trophoblast subpopulations does not affect fetal development.

Animals↗
PubMed1998

TNF-alpha expression in embryos exposed to a teratogen.

PROBLEM: The role of tumor necrosis factor (TNF)-alpha produced by embryonic cells in normal and abnormal development is poorly understood. To assess to what extent TNF-alpha may be involved in the process of induced dysmorphogenesis, the expression of TNF-alpha and TNF-alpha receptor (TNFRI) mRNA as well as TNF-alpha protein was evaluated in embryos responding to a cyclophosphamide (CP)-induced teratogenic insult. The effect of maternal immunostimulation increasing the embryo's tolerance to CP on TNF-alpha expression was also investigated. METHOD OF STUDY: ICR female mice were treated intraperitoneally with 40 mg/kg CP on day 12 of pregnancy. The immunostimulator, xenogeneic rat splenocytes, was injected intrauterine 21 days before mating. Embryos were collected on days 13, 14, or 15 of pregnancy. TNF-alpha mRNA, TNFRI mRNA, and TNF-alpha protein expression were evaluated by in situ hybridization and immunostaining techniques in control, teratogen-treated, and immuno-stimulated teratogen-treated embryos. RESULTS: CP-treated embryos showed severe external brain and craniofacial anomalies already visible on day 14 of pregnancy. TNF-alpha mRNA transcripts were detected in cells of the brain and the head of 13-day embryos, which preceded the occurrence of CP-induced external craniofacial anomalies. On day 15 of pregnancy, when severe craniofacial anomalies increased, a significant increase in the intensity of TNF-alpha, TNFR1 mRNA transcripts, and TNF-alpha protein expression were observed in cells of the malformed regions of the head and the brain. In other nonmalformed organs of CP-treated embryos such as the liver (not macroscopically different from controls), neither TNF-alpha nor TNFR1 transcripts were detected. Immunostimulation substantially diminished the severity of CP-induced brain and craniofacial anomalies, decreased the resorption rate, and was associated with decreased intensity of TNF-alpha mRNA transcripts detected on day 15 of pregnancy in the head and the brain of CP-treated embryos. CONCLUSIONS: TNF-alpha expressed in the embryo may be one of the molecules promoting the formation of CP-induced brain and craniofacial anomalies. The decrease of TNF-alpha expression in embryos of immunostimulated females may be one of the mechanisms responsible for the increased tolerance to the teratogenic insult.

Animals↗
PubMed1997

Immunostimulation increases the resistance of mouse embryos to the teratogenic effect of diabetes mellitus.

The present work was aimed to assess the possible effect of stimulation of the maternal immune system on the teratogenic potential of diabetes mellitus. ICR female mice were immunized with splenocytes of male rats 3 weeks before the beginning of mating and were injected with 240 mg/kg streptozocin (STZ) 10 days after immunization. Females with blood glucose levels over 27.8 mmol/l and HbA1c levels over 6 standard deviations (SD) above the mean of intact animals were used for teratological studies. The rate of malformed fetuses, resorptions and fetal weights were evaluated for animals killed on day 19 of pregnancy using routine teratological methods. Also, phenotyping of spleen cells of these females was performed by fluorescein activated cell sorter analysis. Two main effects possibly due to immunostimulation of ICR females were observed: 1) immunostimulated females had significantly fewer litters with malformed fetuses than non-immunized females: only 4 litters out of 22 (18%) compared to 10 out of 16 (63%). Correspondingly, the incidence of malformed fetuses was also decreased: 2.1 compared to 8.9%; 2) a significant increase in the pregnancy rate in immunized diabetic ICR mice: 69% as compared to 44% in non-immunized diabetic females. Also, immunostimulation resulted in a visible increase in spleen cellularity and a certain increase in the number of cells with mature T-cell and macrophage surface markers. These results strongly suggest that immunostimulation increases the tolerance of ICR females to the teratogenic effect of STZ-induced diabetes.

Adjuvants, Immunologic↗
PubMed1997

A new transmissible AIDS-like disease in mice induced by alloimmune stimuli.

The search for a suitable and reliable animal model for human AIDS that is easy to use on a large scale continues. Here we describe a new condition in mice that closely resembles human AIDS, namely, chronic lymphoproliferation with dramatic depletion of CD4-positive cells, progressive impairment of the immune responses, and Kaposi's sarcoma-like tumors or terminal B-lymphomas. The AIDS-like disease was primarily induced by mating BALB/c female mice to C57BL/6 males during a 1-year period (7-10 allogeneic pregnancies) followed by immunization with paternal lymphocytes. The disease is sexually and vertically transmissible, transferrable by cell-free plasma and is associated with autoimmune reactions to major histocompatibility complex antigens and CD4 cells. We hope that this becomes a model for studying the mechanisms of AIDS immunopathogenesis and immune-based treatment approaches.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Allogenic leukocyte immunization after five or more miscarriages. Recurrent Miscarriage Immunotherapy Trialists Group.

Rather than investigate whether paternal leukocyte immunization improves the live birth rate in women with three or more abortions, we analysed the results of patients expected to have a poor outcome in a subsequent pregnancy if untreated, i.e. women with five or more abortions and no anti-paternal complement-dependent antibody (APCA) at initial testing. The analysis included the results of patients treated by us over the last 8 years and the results of randomized and non-randomized trials reported by the Recurrent Miscarriage Immunotherapy Trialists Group. Patients with a previous live birth were classified into two groups: secondary aborters if there was an initial live birth followed by miscarriages, or tertiary aborters if there were miscarriages followed by a live birth and at least three subsequent miscarriages. The results were evaluated separately for primary, secondary and tertiary aborters who demonstrated APCA activity as a result of immunization. The 107 primary aborters had double the live birth rate if immunized, with an overall benefit of 31%. The 45 tertiary aborters had an almost 3-fold increase in the live birth rate, with an absolute benefit of 50%. The number of patients needed to treat to achieve one extra live birth was three to four primary aborters or two tertiary aborters. Immunization had little beneficial effect in secondary aborters but was effective in preventing abortion in primary or tertiary aborters with five or more abortions.

Abortion, Habitual↗
PubMed1997

Use of antibodies against the human antigen of erythroblasts for the detection of nucleated erythrocytes in the maternal circulation.

In the present study, we tried to detect nucleated erythrocytes in maternal blood by means of the HAE9 antibody that binds to the antigen of erythroblasts (Ag-Eb) on nucleated erythroid cells. Umbilical cord blood and placental cells, which are known to contain a high number of nucleated erythrocytes, indeed demonstrated a high percentage of Ag-Eb-positive cells. In comparison, HAE9 stained up to 4.5% of the peripheral blood cells collected from pregnant women, but not those of nonpregnant women or normal men. These results, demonstrating a simple and reliable method for the identification of nucleated erythrocytes in the maternal circulation using the anti-Ag-Eb antibody, might open new possibilities for the detection of nucleated erythrocytes in maternal blood.

Antibodies, Monoclonal↗
PubMed1997

A new retroviral AIDS-like disease and/or acute leukemia induced in mice by alloimmune stimuli.

We have shown a new phenomenon demonstrating that BALB/c female mice mated to C57BL/6 males during a year (7-10 pregnancies) develop AIDS-like disease or acute leukemia after an additional immunization with fixed ConA activated paternal (C57BL/6) lymphocytes. The AIDS-like disease is sexually and vertically transmissible and easily transferable to intact BALB/c and C57BL/6 mice by filtered plasma of affected animals.

Acquired Immunodeficiency Syndrome↗
PubMed1997

In vivo evidence for the existence of a threshold for hyperglycemia-induced major fetal malformations: relevance to the etiology of diabetic teratogenesis.

The present study was carried out to evaluate whether hyperglycemia-induced major fetal anomalies are thresholded phenomena. Streptozotocin (STZ)-treated female ICR mice were examined on day 19 of pregnancy by methods routinely used in Segment II teratological studies. Simultaneously, the glucose and hemoglobin A1c (HbA1c) levels in maternal-blood were measured and mice with glucose levels > 9.5 mmol/l (mean + 3 SD) were considered to be diabetic. The occurrence of litters with fetuses having gross structural anomalies was clearly associated with glucose levels > 27.8 mmol/l. A wide range of HbA1c levels (between 6 and 18 SD above the mean) were observed, within which only single malformed fetuses were found in the litters of diabetic females. A decreased pregnancy rate in diabetic ICR mice was associated with glucose levels > 16.7 mmol/l and with HBA1c levels > 6 SD above the mean. The results of this study suggest that there is a threshold glucose level associated with a clear increase of the number of litters with severely malformed fetuses in diabetic ICR mice. Results of this study also suggest the existence of HbA1c-associated factors determining, along with glucose, the teratogenic response of ICR mice to diabetes. The interpretation of results obtained in terms of the multifactorial/threshold model leads to the hypothesis that the teratogenic potential of diabetes may consist of two components; one associated with 'direct' teratogens perturbing developmental processes in embryos at a 'critical moment' in organogenesis, and a second component, associated with a direct or indirect influence of the diabetic environment on developmental processes in the preimplantation embryos.

Animals↗
PubMed1996

Teratogen-induced apoptosis may be affected by immunopotentiation.

Intra-uterine immunization of mice with paternal allogeneic or xenogeneic (rat) splenocytes was found to increase embryo tolerance to cyclophosphamide (CP)-induced teratogenesis. As the CP-induced teratogenic effect was shown to be associated with apoptosis, the present study was designed to investigate whether the protective effect of immunopotentiation may be realized via an alteration of CP-induced apoptosis. Various doses of CP were injected intraperitoneally into ICR mice on day 12 of pregnancy. Intra-uterine immunization with xenogeneic rat splenocytes was carried out 3 weeks before mating. Implantation sites, resorptions, live and dead fetuses, as well as soft tissue anomalies and external malformations, were recorded to evaluate the CP-induced embryotoxic effect. In parallel, flow cytometric analysis and DNA fragmentation assay were used for evaluation of CP-induced apoptosis in limbs, tail and whole embryos. The treatment of mothers with a high dose of CP induced the death of almost all embryos and striking fetal growth retardation in survivors. This strong embryotoxic effect was accompanied by very prominent DNA degradation in cells collected from whole embryos. Immunostimulation caused a dramatic decrease of embryonal loss (by approximately 50%) and a significant (about 30%) increase in fetal weight. Such an increase in fetal survival and in fetal weight was found to be accompanied by a clear decrease in apoptosis level in embryo cell population as judged by DNA gel electrophoresis with subsequent quantitation of DNA fragmentation in negatives by an image analysis technique. After treatment with a low dose of CP, a decrease in the proportion of fetuses with limb and tail anomalies in immunized females was accompanied by a decrease in the proportion of apoptotic nuclei in cells taken from limbs and tails. The results of this study suggest that the teratogen-induced apoptosis may, at least partly, be dependent on fetomaternal immune interactions.

Adjuvants, Immunologic↗
PubMed1996

Intravenous immunoglobulin in women with five or more abortions.

PROBLEM: Treatment for recurrent miscarriage has usually been given to all women with three or more abortions of unknown cause. As these patients have a 50-60% subsequent live birth rate, no treatment has been shown to unequivocally improve the live birth rate. Immunoglobulin is the latest treatment to be applied. In order to determine if immunoglobulin improves the live birth rate, we analyzed the results of patients expected to have a poor outcome in the subsequent pregnancy if left untreated, i.e., women with five or more abortions, who have aborted after paternal leucocyte immunization or who continue to abort despite possessing anti-paternal complement dependent antibody (APCA). METHODS: A preliminary trial was carried out using immunoglobulin (Sandoglobulin, Sandoz, Switzerland). It was infused at a dose of 400 mg/Kg body weight, in the follicular phase of a cycle in which pregnancy was planned. A booster dose was administered as soon as pregnancy was diagnosed. RESULTS: Twelve patients were treated, ten conceived. Five have had subsequent live births. Two infants were premature but their size was appropriate for gestational age. The other three infants delivered at term. CONCLUSIONS: This is still too small a group from which to draw definite conclusions about the efficacy of immunoglobulin to prevent abortion. However, five live births in ten patients is an encouraging result, especially when the expected poor obstetric outcome is considered. Hence the efficacy of immunoglobulin should be evaluated further in high risk patients.

Abortion, Habitual↗