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[en] We describe here the expression of c-fos oncogene in the growth stimulated cells e.g., mouse prenatal tissues, FCS treated NIH-3T3 fibroblast and A549 human lung cancer cells. Total cellular RNA was isolated from A/J and C57BL/5J mouse embryos at the 13 and 17 day of pregnancy. NIH-3T3 mouse fibroblast and A549 lung cancer cells were stimulated using the 15% FCS after serum depletion for 2-3 days. During the serum stimulation, c-fos expression was detected at time intervals by the dot blot analysis using the 32 P-labelled c-fos DNA probe. RNAs isolated from mouse prenatal tissues were strongly hybridized with c-fos. c-fos induction was detected from 30 minutes after serum stimulation in NIH-3T3 cells, and turned off after 2hrs. On the other hand, c-fos in the A549 lung cancer cells was independent on the serum stimulation and very strongly expressed even in the serum depleted codition. These results indicate the possible implication of growth control by the turning off the oncogene expression. (Author)
[en] Several protocols of plant regeneration via somatic embryogenesis from Sorghum bicolor (L.) Moench have been development, however the percentage of calluses with embryogenic structures and plant regeneration are low. Therefore this study aimed to generate somatic embryos in red sorghum variety CIAP 132-R. Different concentrations of 2,4-D for callus formation, and three concentrations of ascorbic acid to remove phenolics exudation were assayed by explant. For the formation of embryos different concentrations of 2,4-D and 6-BAP were evaluated. The highest percentage of callus formation (57.5 %) was achieved with 18.1 μM 2,4-D. With the addition to the culture medium of 50.0 mg.l-1 of ascorbic acid was possible to eliminate the phenolic compounds in the explant and in the culture medium; also it allows increasing the percentage of calluses with embryogenic structures up to 95 %. The highest number of somatic embryos per callus was achieved with a reduction in the culture medium of 2,4-D to 4.52 μM in combination with 2.22 μM 6-BAP. For the first time, the efficiency of somatic embryo formation was obtained from the freshly germinated sprouts of immature seeds as initial explant CIAP 132-R.
[en] Complete text of publication follows. Brain damage induced by prenatal irradiation is of major concern in radioprotection. The brain is the final result of a series of well timed consecutive or concomitant waves of cellular proliferation, migration, and differentiation. Acute irradiation during pregnancy could selectively disturb these events to result in various forms of malformation such as microcephaly, reduced cortical thickness and mental retardation. Such events were previously described in epidemiological studies of the atomic bomb survivors of Hiroshima/Nagasaki. Using cDNA-microarrays and real-time PCR we analyzed the modulated genes upon 50 cGy X-ray irradiation in embryonic mouse brain. The main activated pathways are involved in the induction of Trp53 dependent programmed cell death, and the intercellular signalling cascades. The strong upregulation of Ccng1, Trp53inp1 and Cdkn1a suggested that the tumour suppressor P53 is an essential regulator of the radiation induced stress response. Although in the Trp53 null mutant embryos, our data highlights differential expression of genes involved in cell cycle progression. Various cyclins and cyclin-dependent kinases were down regulated. Regional analysis of the irradiated anterior brain at E15 by in situ hybridization with Trp53inp1 and Ccng1 probes, suggested that there is a specific regional dependent expression in the anterior brain. Especially Ccng1 and the P53 downstream cell cycle regulating gene indicated that the strongest effect can be observed in the cerebral cortex. Taken together, radiation induced cell death of astrocytes in the cerebral cortex, and reduction in neurite length in maturating neurons, may interfere with a correct patterning of the brain and could jeopardize the formation of a correct neural network, leading to cognitive deficits in the mature brain.
[en] Embryonal cell carcinoma is one of the malignant germ cell tumors. This tumor is commonly encountered in the testis, however, it rarely occurs in the ovary. To the best of our knowledge, no imaging findings of ovarian embryonal cell carcinoma have previously been reported. We describe the US and MRI findings of such a case
[en] The ICR pregnant mice were irradiated at 1.5Gy in every 6 hours in the period of organogenesis in order to classify the stage specificity of the embryonic effects of radiation and the stage of development differentiation of the primordium of each major organ. Intrauterine death, fetal body weight and external malformation in live fetuses were observed on day 18 of gestation. There was no statistically significant difference in the intrauterine mortality at any stage organogenesis. The fetal body weight of the mice irradiated in the intermediate stage of organogenesis showed significantly lower. There were specific highly sensitive stages in the incidences of each external malformation, that is exencephalia, open eyelid, cleft palate, anomalies of extremities and anomalies of the tail. At these stage, the primordial of the major organs are established in ICR mice
[en] Birth defects belong to the most serious side effects of pharmaceutical compounds or environmental chemicals. In vivo, teratogens most often affect the normal development of bones, causing growth retardation, limb defects or craniofacial malformations. The embryonic stem cell test (EST) is one of the most promising models that allow the in vitro prediction of embryotoxicity, with one of its endpoints being bone tissue development. The present study was designed to describe three novel inexpensive endpoints to assess developmental osteotoxicity using the model compounds penicillin G (non-teratogenic), 5-fluorouracil (strong teratogen) and all-trans retinoic acid (bone teratogen). These three endpoints were: quantification of matrix incorporated calcium by (1) morphometric analysis and (2) measurement of calcium levels as well as (3) activity of alkaline phosphatase, an enzyme involved in matrix calcification. To evaluate our data, we have compared the concentration curves and resulting ID50s of the new endpoints with mRNA expression for osteocalcin. Osteocalcin is an exclusive marker found only in mineralized tissues, is regulated upon compound treatment and reliably predicts the potential of a chemical entity acting as a bone teratogen. By comparing the new endpoints to quantitative expression of osteocalcin, which we previously identified as suitable to detect developmental osteotoxicity, we were ultimately able to illustrate IMAGE analysis and Ca2+ deposition assays as two reliable novel endpoints for the EST. This is of particular importance for routine industrial assessment of novel compounds as these two new endpoints may substitute previously used molecular read-out methods, which are often costly and time-consuming.