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M Vandeputte

Publications and source records attributed to M Vandeputte.

At least 127 records · Page 7Linked to original sources
PubMed1983

Yolk sac-derived malignant tumors develop in the absence of germ cells.

Malignant tumors composed of extra-embryonic tissues are considered to be of germ cell origin. Since such tumors can also originate from displaced yolk sac we verified whether these neoplasms develop from germ cells possibly present in this fetal membrane. For this purpose we treated pregnant rats with Busulphan. This drug, which is known to destroy germ cells during their migratory phase, led to the complete absence of these cells in genital ridges of 12-day-old embryos removed during fetectomy. This treatment, however, did not influence the incidence or the latency period of yolk sac carcinomas or teratocarcinomas. Therefore, it is concluded that malignant yolk sac-derived tumors are not of germ cell origin.

Animals↗
PubMed1982

Trophoblastic and mesenchymal structures in rat yolk sac carcinoma.

The presence of trophoblastic and mesenchymal structures in primary as well as in transplanted rat yolk sac carcinomas (YSC) is described. These structures were only recorded in rat yolk sac carcinomas derived from displaced yolk sac but never in embryo-derived yolk sac carcinomas. It is suggested that the endodermal carcinoma cells displaying either a parietal or a visceral yolk sac pattern as well as the mesenchymal and trophoblastic structures may have a common cell ancestor.

3-Hydroxysteroid Dehydrogenases↗
PubMed1982

Influence of overall treatment time in a fractionated total lymphoid irradiation as an immunosuppressive therapy in allogeneic bone marrow transplantation in mice.

Three groups of C57/BL/Ka mice received total lymphoid irradiation (TLI) in a total dose of 34 Gy in three different fractionation schedules. In the first group daily fractions of 2 Gy were given during 3 1/2 weeks. In the second group 4 to 5 fractions with 3 1/2 hr interval were given each day, thus delivering 17 fractions in 4 days. In the third group three fractions were given daily for two consecutive days and was repeated two times after 8 or 9 days interval, resulting in a total treatment time of 3 1/2 weeks. The tolerance of all different schedules was excellent. No difference in the peripheral white blood cell and lymphocyte counts nor the degree of immunosuppression as measured by phytohaemaglutinin or concanavalin A induced blastogenesis and mixed lymphocyte reaction were observed at the end of the treatment and up to 200 days. When bone marrow transplantation was performed one day after the end of each schedule, chimerism without signs of graft versus host disease was induced in all the groups. However, from the results in a limited number of animals it seems that concentrated schedules were less effective for chimerism induction. It has been demonstrated that it is possible to reduce drastically the overall treatment time for TLI before bone marrow transplantation. Further investigations are necessary in order to determine the optimal time-dose-fractionation factors and the different parameters involved in the transplantation.

Animals↗
PubMed1982

Viral-versus non-viral-induced yolk sac tumors in the rat.

Yolk sac tumors were induced in fetectomized rats by displacement of the visceral yolk sac outside the uterus with or without injection of murine sarcoma virus (MSV) into the placenta. Some of the animals were immunized with MSV prior to surgery. The biological, morphological and immunological characteristics of the tumors which develop in animals either injected or not with virus are compared. The results indicate that MSV inoculation into the placenta increases the tumor incidence, shortens the latency period, and induces, apart from yolk sac carcinoma (YSC), less differentiated tumors (embryonal cell carcinoma, EC). The transplanted and/or in vitro cultured YSC derived from primary tumors obtained in animals either injected or not with MSV show the same morphology, are not immunogenic, secrete alphafetoprotein and express endodermal antigen.

Animals↗
PubMed1982

Cellular events during early formation of yolk-sac-derived teratomas.

A sequential morphological study of the initial cellular events in teratoma induction by displaced visceral yolk sac after foetectomy in rats was undertaken. This study led to the observation that apart from proliferation of cells displaying definite endodermal or mesodermal characteristics, a population of poorly differentiated cells appeared some days after the surgical procedure. It is very likely that these poorly differentiated cell are stem cells from which differentiated structures originate afterwards by a process of redifferentiation. The development of granulation tissue rich in capillaries seems to enhance this process. Similarities and differences with blastema formation are discussed.

Animals↗
PubMed1981

Surface antigen (S) common to rat and mouse embryonal carcinoma cells and to pre-implantation embryos.

Five R rat embryonal carcinomas were induced by inoculating MSV into the placenta of fectotomized rats. Anti-embryonal carcinoma antisera were prepared by allogeneic or xenogeneic immunization with ascitic embryonal carcinoma cells. To remove the non-specific activity both antisera were absorbed in vivo and in vitro. By indirect immunofluorescent assay these absorbed antisera were reactive only on rat embryonal carcinomas and on undifferentiated primitive teratocarcinoma cells of C3H and 129/SV mouse. They did not react with the differentiated cells of mouse teratocarcinomas, with other rat and mouse tumors and with various normal rat and mouse tissues including spermatozoa. A positive reaction was found on mouse and rat pre-implantation embryos from the 4-cell stage to late blastocyst.

Animals↗
PubMed1980

Induction of immune reaction against rat embryonal carcinoma by activation of viral genome.

A cell line (F3/1) derived from a rat embryonal carcinoma, originally induced in fetectomized rats injected with MSV, was found to be essentially non-immunogenic in a syngeneic host; the cells did not produce C-type virions. The MSV genome could be rescued by superinfection of F3/1 cells with endogenous C-type mouse virus and the cells were converted in a producer line-F3/1-P. The produced virus was shown to be MSV by its ability to induce focus formation in mouse fibroblasts. In contrast to its non-producer ancestor, the F3/1-P line proved to be strongly immunogenic in the syngeneic host. These results indicate the possibility of converting certain non-immunogenic tumors into immunogenic ones by the activation of dormant viral genome using xenogeneic non-oncogenic helper virus.

Animals↗
PubMed1979

Potentiometric determination of iodine in pharmaceutical preparations.

Methods for the determination of organically bound iodine were compared. A preliminary destruction of the sample was preferable. The sample was mineralized using the Schöniger combustion. Since direct potentiometry of the iodide ion was used, further reduction of the sample was necessary. Several reductors were compared, and the best results were obtained with Devarda alloy. The proposed method was amployed for the determination of iodine in X-ray contrast products. Pure compounds and pharmaceutical preparations were investigated. The coefficient of variation of the method was 0.9%.

Iodine↗
PubMed1979

X-ray fluorescence and potentiometry compared for determining iodine content of thyroid glands.

We compare results for iodine quantitation by x-ray fluorescence of excised thyroid glands with results of the quantitation by means of an original, newly developed chemical method, a Schöniger combustion technique, in which iodie is quantitated potentiometrically. Subsequently, we establish the accuracy and clinical suitability of the former technique in quantifying the intrathyroidal iodine.

Humans↗
PubMed1978

Presence of common surface antigens(s) on endodermal tumors and embryonal tissues of rats, hamsters and mice.

Antiserum against yolk-sac carcinoma of rat was prepared in rabbits. After appropriate absorption in vitro or in vivo this antiserum was examined on different tumors and normal tissues or rat, hamster and mouse. The methods used were indirect immunofluorescence and indirect immunoperoxidase staining and cytotoxicity tests. The immune serum was found to react with the cell membrane of different rat and hamster yolk-sac carcinomas. It reacted also with the cell surface of rat hepatoma cells. By absorption on hyalin and blocking with amniotic fluid it was shown that the antigen was neither a basement membrane component nor alpha-fetoprotein. The antiserum was cytotoxic to yolk-sac carcinoma and hepatoma cells. The immune reaction was limited to the cell membrane, as observed in immunofluorescence and in immunoperoxidase staining. The specificity of the antiserum was proved by cross-absorptions with various tumor lines and by removing its activity with the soluble fraction of yolk-sac carcinoma cells. Non-endodermal rat and hamster tumor lines did not react with the anti-yolk-sac carcinoma immune serum. Most normal adult tissues, including spermatozoa, were negative, but a positive reaction was observed in ovaries and on glandular cells of the uterus. In embryonal tissues this surface antigen(s) was detected in the endoderm of 8-day-old rat embryos 7-day-old mouse embryos and in yolk-sac endoderm of both species. The data indicate that the antigen(s) is associated with endodermal differentiation.

Animals↗
PubMed1978

Immunological enhancement of hybrid teratomas derived from yolk sac.

Visceral yolk sac displaced outside the uterus after fetectomy differentiates into benign teratomas. This differentiation only occurs in a syngeneic pregnancy but never in hybrid pregnancy. Hybrid teratomas, however, were obtained after the induction of active or passive immunological enhancement. These hybrid teratomas, although smaller than the syngeneic, contained tissues derived from the three germ layers.

Animals↗
PubMed1978

Viruslike particles in hamster embryos, fetuses, and tumors.

Intracisternal viruslike particles were present in outbred Syrian golden and inbred ALB/Mey Pfd hamster blastocysts, embryos, and fetuses. Their morphology was identical to that of the "spoked" viruslike particles found in hamster tumors. They were released in great numbers in the embryonal tissues until day 9 of pregnancy and were found until day 13 in the fetal tissues. Thereafter, these viruslike particles were no longer observed in the fetus. They were never recorded in normal adult hamster tissues.

Animals↗