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Biomedical subjects

H Spielmann

Publications and source records attributed to H Spielmann.

At least 73 records · Page 4Linked to original sources
PubMed1981

Investigations on cyclophosphamide treatment during the preimplantation period. I. Differential sensitivity to maternal cyclophosphamide treatment.

To study the effect of cyclophosphamide (CPA) treatment of pregnant mice during the preimplantation period on different embryonic cells even before implantation, the cell numbers of the immunosurgically isolated inner cell mass (ICM) and the blastocyst total cell number (BTCN) were determined in late blastocysts. In animals treated at 2 P.M. on day 2 of pregnancy a dose-related reduction of the cell numbers was found for both ICM and BTCN in morphologically normal late blastocysts (day 4, 8 A.M.) at CAP doses of 20-60 mg/kg which did not induce embryonic death before implantation but did later during organogenesis. At identical CPA doses the reduction of the cell numbers of the ICM was significantly greater than that of the BTCN. These data provide evidence for a differential sensitivity of the two groups of cells in preimplantation mouse embryos (trophectoderm and ICM) to maternal CPA treatment even before implantation.

Animals↗
PubMed1981

Investigation on cyclophosphamide treatment during the preimplantation period. II. In vitro studies on the effects of cyclophosphamide and its metabolites 4-OH-cyclophosphamide, phosphoramide mustard, and acrolein on blastulation of four-cell and eight-cell mouse embryos and on their subsequent development during implantation.

Preimplantation mouse embryos were cultured for 48 hours from the four-cell and eight-cell stage to the blastocyst stage in the presence of cyclophosphamide (CPA) or one of its metabolites-4-hydroperoxy-CPA (4-HP-CPA), phosphoramide mustard (PAM), and acrolein (Acr)--to identify the metabolite which is embryotoxic after CPA treatment of pregnant mice during the preimplantation period. The dose-response relations for the inhibition of blastulation revealed identical inhibition curves for PAM and 4-HP-CPA (in solution 4-HP-CPA immediately decomposes to 4-hydroxy-CPA (4-OH-CPA)). These two metabolites are inhibiting blastulation in vitro at concentrations that are 10,000 times lower than CPA and 100 times lower than acrolein. When blastocysts which had developed in the presence of CPA and its metabolites in vitro were subsequently cultured in inhibitor-free medium NCTC-109, the same dose-response relationship pattern was obtained. Since 4-OH-CPA decomposes into acrolein and PAM in vivo and in vitro and since PAM and 4-OH-CPA exhibit identical embryotoxicity towards preimplantation embryos in vitro, PAM probably also is an active embryotoxic CPA metabolite in vivo before implantation. This result is discussed in relation to the importance of alkylating CPA metabolites in cancer treatment and in teratological studies during organogenesis.

Acrolein↗
PubMed1981

Decidual changes in the rat following cyclophosphamide treatment before implantation.

To explain the teratogenic action of cyclophosphamide treatment during the preimplantation period (day 3; 60 mg/kg), the decidual reaction of the uterus was studied in the rat by light microscopy and autoradiography on day 4 (preimplantation period) and on days 5 and 6 (implantation period). On day 4, 24 h after cyclophosphamide treatment, the 3H-thymidine labelling index of the stroma cells beneath the uterine epithelium was significantly increased (33.7 +/- 5.2%) as compared to untreated control animals (6.5 +/- 0.4%). In addition, the surface of the uterine lumina appeared smoother in treated animals than in controls. On day 5 of gestation no difference could be detected autoradiographically between the uteri and treated and untreated animals. Histologically, however, the decidual reaction in treated animals occupied a larger area than in controls. On day 6 of pregnancy the 3H-labelling index of stroma cells surrounding the implantation site of treated animals was considerably reduced (10.7 vs. 32.8% in controls) and necrotic stroma cells were found in the area around the implantation site. Mechanisms inducing the decidual changes in cyclophosphamide-treated animals are discussed.

Animals↗
PubMed1980

Immunosurgical studies on inner cell mass development in rat and mouse blastocysts before and during implantation in vitro.

Eighty per cent of rat blastocysts (Wistar, SW72) cultured for 96 h in NCTC-109 supplemented with fetal calf serum (FCS) hatched from the zona pellucida and developed a trophoblast giant cell lyer. Thirty seven per cent from the rat blastocysts developed an inner cell mass (ICM) which, in about 7% consisted of two germ layers (ectoderm and endoderm) compared to 84% in NMRI mice. A significantly better ICM development was obtained with cultured rat blastocysts that had hatched in vivo. Similar to the in vivo situation LDH-5 was present in rat blastocysts after implantation in NCTC-109-FCS. Differentiation of C57BL mouse blastocysts in NCTC-109-FCS proceeded as poorly as in the rat. ICM development of rat and mouse blastocysts in NCTC-109-FCS was studied in detail. ICMs of the two species were isolated immunosurgically using complement from different species, e.g. human, rat and rabbit complement, since guinea-pig complement did not lyse trophectoderm cells of rat blastocysts. All immunosurgically isolated rat ICMs degenerated within 48 h, but mouse ICMs isolated with rat or rabbit complement developed significantly better than mouse ICMs isolated with guinea-pig complement. Determinations of the blastocyst total cell number (BTCN) and of the cell number of immunosurgically isolated ICMs were performed in rat and mouse blastocysts to investigate growth kinetics of the ICM before implantation in vitro. In the mouse an exponential increase in both BTCN and cell number of the ICM was observed during the 48 h before implantation in NCTC-109-FCS and also during the 16-24 h before implantation in vivo. In the rat, doubling of the BTCN was found only during the first 24 h in NCTC-109-FCS and there was hardly any increase in the cell number of the ICM during the first 48 h in culture. ICM growth of blastocysts in NCTC-109-FCS is therefore, stimulated in the mouse before and after implantation and in the rat it is inhibited already before implantation.

Animals↗
PubMed1980

[Anti-arrhythmic effect of dazolicin. Clinical-pharmacological research].

8-Chloro-6-[(1-isopropyl-3-imidazolin-2-yl)-methyl]-1,6-benzoperhydrothiazocin-hydrochloride (dazolicin, ucb B 192) is a new antiarrhythmic drug with direct membrane action which was applied both orally and parenterally. The immediate antiarrhythmic effect of a single i.v. injection of 150 mg of dazolicin on the average was investigated in 28 patients with various types of arrhythmia. After i.v. injection the drug proved to have very strong antiarrhythmic potency and rather a low incidence of side effects. Ectopic beats and paroxysmal tachycardias of both ventricular and supraventricular origin were successfully treated with dazolicin. The antiarrhythmic drug significantly increased the duration of both the QRS- and QT-interval after correction for frequency but it had no detectable effects on the atrioventricular conduction time. After i.v. administration the antiarrhythmic effects of the drug lasted for several hours. The elimination half-life of dazolicin was 7 h. Oral treatment with dazolicin was attempted in 10 patients suffering from stable extrasystolic arrhythmia with daily doses ranging from 3 x 25 mg to 3 x 50 mg. In only 4 patients ectopic beats could sufficiently be eliminated. According to the low dosage the maximum serum concentrations after oral application were significantly lower than after i.v. injection. In two patients serious side effects were observed, such as paroxysmal ventricular fibrillation and an increase in frequency and polymorphism of ventricular ectopic beats. In both instances the patients were suffering from congestive heart failure and they had TU abnormalities in the ECG.

Administration, Oral↗
PubMed1980

In vitro methods for the study of the effects of teratogens on preimplantation embryos.

In vitro culture methods are described for mouse embryos during the preimplantation period (Whitten's medium) and for mouse and rat blastocysts during the time of implantation (NCTC-109 medium). Examples are given for the influence of the genetic background (strain differences) on in vitro development and for the detection of a DNA repair mechanism in cultured preimplantation embryos. S-shaped dose effect curves were obtained for the influence of UV-irradiation and cyclophosphamide (CPA) and its metabolites on development of pre implantation mouse embryos treated during in vitro culture. Similar curves were obtained for mouse blastocysts cultured at implantation after treatment of the mother with either CPA or the steroid sex hormones cyproterone acetate (CA) or medroxyprogesterone acetate (MPA). The embryo transplantation technique is described as a teratological method to test the viability of preimplantation mouse embryos which have incorporated the stable isotope 13C during in vitro culture. The importance of the in vitro culture techniques and of the transplantation method in experimental teratology during the earliest period of pregnancy is discussed.

Acrolein↗
PubMed1978

Expression of lactate dehydrogenase isozyme 5 (LDH-5) in cultured mouse blastocysts in the absence of implantation and outgrowth.

Extensive extraction studies with Triton X-100 revealed only LDH-1 (B4) but no trace of LDH-5 (A4) in one-cell and two-cell mouse and rat embryos. The LDH isozyme pattern of preimplantation mouse embryos changes from the maternally inherited B subunit isozyme (LDH-1) to a pattern dominated by LDH-5 when mouse blastocysts are cultured under conditions that prevent hatching but allow trophoblast giant cell transformation. During differentiation of mouse blastocysts in vitro, implantation is therefore not essential for the appearance of the A subunit form of LDH (LDH-5) coded for by the embryonic genome. Mechanisms controlling the expression of LDH-5 in mouse blastocysts during in vivo development are discussed.

Animals↗
PubMed1978

Recent progress in teratology. A survey of methods for the study of drug actions during the preimplantation period.

To evaluate the effects of drug treatment during the first days of pregnancy new approaches have been developed which allow the study of teratogenic effects already before and around implantation, during organogenesis, and at term. The procedures used for the culture of preimplantation mouse embryos that were either pretreated in vivo or previously untreated and exposed to a toxic agent in vitro are presented in particular detail. In addition, an example is given which shows that it is possible to detect a DNA repair mechanism in preimplantation embryos maintained in vitro. The techniques of embryo transplantation and in vitro cultivation of embryos beyond implantation are outlined. The importance of the two methods in teratological research on embryos pretreated either in vivo or in vitro is discussed. Also presented are a survey of the literature and recent data obtained with rats and mice from our laboratory which prove that the action of drugs on the embryo and mother during the preimplantation period are more complex than is generally assumed.

Abnormalities, Drug-Induced↗
PubMed1977

Studies on the binding of antibody against mouse lactate dehydrogenase (isoenzyme X) by preimplantation mouse embryos.

The binding of antibodies against LDH-X by preimplantation mouse embryos was studied to detect LDH-X from spermatozoa in embryos after fertilization. Incubation of preimplantation mouse embryos with rabbit anti-mouse-LDH-X-IgG and then with peroxidase-labelled goat anti-rabbit IgG revealed a strong peroxidase staining of the zona pellucida of normal fertilized and unfertilized 1-cell ova. However, the reaction was significantly weaker with both fertilized and unfertilized 1-cell ova from females induced to superovulate and normal and superovulated blastocysts. Pure antibody against mouse LDH-X was obtained by affinity chromatography of the rabbit anti-mouse LDH-X-IgG on pure mouse LDH-X covalently bound to sepharose. The pure antibody against mouse LDH-X reacted immunochemically identically to anti-mouse LDH-X-IgG, but it was not bound by any stage of preimplantation mouse embryos. The IgG fractions which had passed through the affinity column during the purification procedure and which did not contain any anti-LDH-X activity were bound by the zonae of preimplantation mouse embryos in the same manner as was unpurified anti-mouse LDH-X-IgG. Histochemical studies indicated LDH activity only in the embryo proper, but not on the zona pellucida. It is concluded that LDH-X is not present in preimplantation mouse embryos.

Animals↗
PubMed1977

Effects of cyclophosphamide treatment before implantation on the development of rat embryos after implantation.

After treatment of pregnant rats 24 h before implantation with a single injection of cyclophosphamide (20--80 mg/kg), a dose-dependent increase in resorption was observed at term but no malformed fetuses could be found. The lowest cyclophosphamide dose that caused 100% resoprtion was 60 mg/kg. Somite number and wet weight indicated retardation of about 24 h during organogenesis. Determination of the time of implantation revealed that the developmental retardation in treated embryos was not due to delayed implantation. At implantation, 24 h after cyclophosphamide treatment, a significant and dose-dependent decrease of the cell number of blastocysts was found. Embryo transplantation experiments showed that early cyclophosphamide treatment interfered with the subsequent development of both the embryo and the mother. The decidual reaction seemed to be more affected by the treatment than the embryos. Most teratologists hold that mouse embryos after treatment in the preimplantation period either die before implantation or survive to term without being malformed. The present study, however, proves that the reaction of drugs at this early stage of pregnancy is more complex than is generally assumed.

Animals↗