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PubMed1983

Role of glucocorticoids on the maturation of brush border enzymes in fetal rat gut endoderm.

Heterospecific recombinants between fatal rat intestinal endoderm and chick mesenchyme, and also undissociated fetal rat intestine, were submitted to different hormonal environments. The present study shows that exogenously-supplied dexamethasone in organ culture, like endogenous hormones provided by the adult rat (grafting experiments) led to similar qualitative and quantitative results, i.e., a 9-fold stimulation of maltase and a precocious induction of sucrase activity in comparison with an hormonal conditions.

Animals↗
PubMed2005

Vaginal endodermal sinus tumor.

Malignant germ cell tumors are rare tumors of childhood accounting less than 3% of pediatric malignancies, and endodermal sinus tumor (EST) is the most common histological subtype. The vagina is an extremely rare site for germ cell tumors (GCT). A one-year female was admitted with history of bleeding per vagina. She had pallor and a mass was palpable anteriorly on rectal examination. Magnetic Resonance Imaging (MRI) showed a tumor mass at the junction of cervix and vagina and biopsy was suggestive of a vaginal EST. The serum alpha fetoprotein (AFP) was elevated. She underwent vaginohysterectomy. The tumor was excised in toto and patient received four courses of cisplatin, etoposide and bleomycin. At one year of follow up, patient was symptom free and serum AFP remained at normal level. EST of the vagina is a rare, highly malignant GCT that exclusively involves children less than 3 years of age. It is both locally aggressive and capable of metastasis. Even though more conservative surgery is advised to maintain sexual and reproductive function, at times, radical surgery is mandatory depending on the infiltration of the tumor to the surrounding structures. Simple tumor excision is not sufficient, as residual cells induce recurrence and make chemotherapy ineffective. The serum AFP level is a useful marker for diagnosis and monitoring the recurrence of vaginal EST in infants.

Endodermal Sinus Tumor↗
PubMed2002

A rare germ-cell tumor site: vaginal endodermal sinus tumor.

Malignant germ-cell tumors (MGCT) are rare tumors of childhood accounting for less than 3% of pediatric malignancies. Endodermal sinus tumor (EST) forms the most common histologic subtype of MGCT. The vagina is an extremely rare site for GCTs. A 9-month-old female was admitted with a short history of vaginal bleeding, a mass protruding from the vagina, and difficulty in passing urine. She was pale, the bladder was full, and a mass was palpable anteriorly on rectal examination. Ultrasound showed an ovoid, hyperechoic mass posterior to the bladder. A biopsy revealed a vaginal EST. The serum alpha-fetoprotein (AFP) was elevated partial vaginectomy was done and the tumor was excised in toto. The patient was subsequently given six courses of cis-platinum, etoposide, and bleomycin and on follow-up continues to be free from disease. EST is the most common GCT in children. In females, it is usually encountered in the ovary. EST of the vagina is a rare, highly malignant GCT that exclusively involves children less than 3 years of age. The diagnosis is based on histology and raised AFP. Vaginal EST is both locally aggressive and capable of metastasis. Untreated patients have died within 2 to 4 months of presentation. Radical surgery leads to a loss of sexual and reproductive function. Long-term irradiation has secondary effects of sterility, aseptic necrosis of the femoral head, and abnormal growth of the pelvic bones. Partial vaginectomy with combination chemotherapy is the most recommended line of treatment. The surgery eradicates local tumor cells and makes subsequent chemotherapy more effective. Simple tumor excision is not sufficient, as residual tumor cells induce early recurrence and make chemotherapy ineffective. The serum AFP level is a useful marker for diagnosis and monitoring the recurrence of vaginal EST in infants.

Endodermal Sinus Tumor↗
PubMed2002

Primordial germ cells originate from the endodermal strand cells in the ascidian Ciona intestinalis.

The origin of germ cells in the ascidian is still unknown. Previously, we cloned a vasa homologue (CiVH) of Ciona intestinalis from the cDNA library of ovarian tissue by polymerase chain reaction and showed that its expression was specific to germ cells in adult and juvenile gonads. In the present study, we prepared a monoclonal antibody against CiVH protein and traced the staining for this antibody from the middle tailbud stage to young adulthood. Results showed that positive cells are present in the endodermal strand in middle tailbud embryos and larvae. When the larval tail was absorbed into the trunk during metamorphosis, the CiVH-positive cells migrated from the debris of the tail into the developing gonad rudiment, and appeared to give rise to a primordial germ cell (PGC) in the young juvenile. The testis rudiment separated from the gonad rudiment, the remainder of which differentiated into the ovary. PGCs of the testis rudiment and the ovary rudiment differentiated into spermatogenic and oogenic cells, respectively. When the larval tail containing the antibody-positive cells was removed, the juveniles did not contain any CiVH-positive cells after metamorphosis, indicating that the PGCs in the juvenile originated from part of the larval tail. However, even in such juveniles, positive cells newly appeared in the gonad rudiment at a later stage. This observation suggests that a compensatory mechanism regulates germline formation in C. intestinalis.

Animals↗
PubMed1998

Movements and stepwise fusion of endodermal precursor cells in leech.

At the four-cell stage, embryos of glossiphoniid leeches comprise identified blastomeres A, B, C and D. Subsequent cleavages of the A, B and C quadrants yield three large, yolk-rich endodermal precursor cells, macromeres A"', B"' and C"'. Eventually, these cells generate the epithelial lining of the gut via cellularization of a multinucleate syncytium. Meanwhile, cleavage in the D quadrant generates ten teloblasts that give rise to segmental mesoderm and ectoderm via stem cell divisions. Here we show that, during cleavage, macromeres A"', B"' and C"' shift clockwise relative to the D quadrant, while C"' comes to envelop the nascent teloblasts. During gastrulation, derivatives of the teloblasts undergo epibolic movements over the surface of the A"', B"' and C"' macromeres to form the germinal plate, from which segmental tissues arise. We find that the three macromeres fuse in a stepwise manner to initiate formation of the multinucleate syncytium; cell C"' fuses about 25 h after the fusion of A"' and B"', and the teloblasts fuse with the macromere-derived syncytium later still. When macromeres are biochemically arrested by microinjecting them with the A chain of ricin, a further difference among the macromeres is revealed. Biochemical arrest of A"' or B"' slightly retards the rate of germinal plate formation, but arrest of C"' frequently accelerates this process.

Animals↗
PubMed1998

Retinoic acid disrupts anterior ectodermal and endodermal development in ascidian larvae and postlarvae.

In vertebrates, excess all-trans retinoic acid (RA) applied during axis formation leads to the apparent truncation of anterior structures. In this study we sought to determine the type of defects caused by ectopic RA on the development of the ascidian Herdmania curvata. We demonstrate that H. curvata embryos cultured in the presence of RA develop into larvae whose trunks are shortened and superficially resemble those of early metamorphosing postlarvae. Despite RA-treated larvae lacking papillar structures they respond normally to natural cues that induce metamorphosis, indicating that chemosensory functionality previously mapped to the most anterior region of normal larvae is unaffected by RA. Excess RA applied during postlarval development leads to a graded loss of the juvenile pharynx, apparently by respecifying anterior endoderm to a more posterior fate. This structure is considered homologous to the gill slits of amphioxus, which are also lost upon RA treatment. This suggests that RA may have had a role in the development of the pharynx of the ancestral chordate and that this function has been maintained in ascidians and cephalochordates and lost in vertebrates.

Animals↗
PubMed2000

Neuroectodermal and endodermal expression of the ascidian Cdx gene is separated by metamorphosis.

Ascidians are a group of invertebrate chordates that exhibit a biphasic life history, with chordate-specific structures developing during embryogenesis (dorsal neural tube and notochord) and metamorphosis (pharyngeal gill slits and endostyle). Here we characterize the expression of a caudal/Cdx gene homologue, Hec-Cdx, from the ascidian Herdmania curvata. Vertebrate Cdx genes are expressed at gastrulation and in the posterior of the developing neural tube and endoderm. Hec-Cdx expression is initiated at the earliest stages of gastrulation, with peaks in RNA abundance occurring first during neurulation and tailbud extension and then in 3- to 5-day-old juveniles. Hec-Cdx is expressed in a pair of cells in the anterior lip of the blastopore in the late gastrula which form the most posterior portion of the neural plate. During tailbud formation expression is maintained in and solely restricted to these cells. During metamorphosis expression is localized to the intestine of the juvenile. These data, along with data for the H. curvata Otx gene, suggest that the evolution of the novel ascidian biphasic body plan was not accompanied by a deployment of these genes into new pathways but by a temporal separation of tissue-specific expression.

Amino Acid Sequence↗
PubMed2001

Prox1 is a marker of ectodermal placodes, endodermal compartments, lymphatic endothelium and lymphangioblasts.

The lymphatic endothelium has mostly been thought to be derived by sprouting from specialized veins. Recently it has been shown that mice deficient for the homeobox transcription factor Prox1 are practically devoid of lymphatics. We have studied the expression of Prox1 mRNA and protein in chick embryos and human fetuses. In the chick, Prox1 is expressed in specific compartments of all germ layers. In the ectoderm, it is found in the neural tube, trigeminal, spinal and sympathetic ganglia and the retina, and also in placodal structures such as the lens, olfactory, otic, facial, glossopharyngeal and vagal placodes, and the apical ectodermal ridge. In the endoderm, Prox1 is a marker of hepatocytes, bile duct and pancreatic epithelium. In the mesoderm, weak expression is observed in cardiomyocytes, and strong expression in lymphatic endothelium. Identical expression domains are found in 19-week-old human fetuses. In day 6.5 chick embryos, there are several sites of contact of lymphatics with the jugular vein, which has a mixed endothelium of Prox1-positive and -negative cells. The only non-lymphatic endothelial cells expressing Prox1 are found on the concave side of the cardiac valves. To further analyse development of lymphatics, we studied early chick embryos and observed scattered Prox1-positive cells in the dermatome, giving rise to Prox1-positive lymphatic networks during subsequent development. Furthermore, the anlagen of the posterior lymph sacs and the paired thoracic duct can already be observed in day-4 chick embryos. Our studies show that lymphatics develop much earlier than previously described, and they mostly do not seem to be derived by sprouting from veins. In contrast, lymphangioblasts are present in the deep and superficial compartments of the early mesoderm, independently giving rise to the deep and superficial lymphatics.

Animals↗
PubMed2003

Loss of beta1-integrin-deficient cells during the development of endoderm-derived epithelia.

Beta1-integrins (beta1) represent cell surface receptors which mediate cell-matrix and cell-cell interactions. Fässler and Meyer described chimeric mice containing transgenic cells that express the LacZ gene instead of the beta1 gene. They observed beta1-negative cells in all germ layers at embryonic day E 8.5. Later in development, using a glucose phosphate isomerase assay of homogenized tissue samples, high levels of transgenic cells were found in skeletal muscle and gut, low levels in lung, heart, and kidney and none in the liver and spleen (Fässler and Meyer 1995). In order to study which cell types require beta1 during development of the primitive gut including its derivatives, chimeric fetuses containing 15 to 25% transgenic cells were obtained at days E 14.5 and E 15.5. They were LacZ (beta-galactosidase) stained "en bloc" and cross-sectioned head to tail. In esophagus, trachea, lung, stomach, hindgut, and the future urinary bladder, we observed various mesoderm-derived beta1-negative cells (e.g. fibroblasts, chondrocytes, endothelial cells, and smooth muscle cells) but no beta1-negative epithelial cells. Since the epithelia of lung, esophagus, trachea, stomach, hindgut, and urinary bladder are derived from the endodermal gut tube, we hypothesize that beta1 is essential for the development and/or survival of the epithelia of the fore- and hindgut and its derivatives.

Animals↗
PubMedDate not supplied

Endodermal sinus tumor of the parotid gland in a child.

We report a case of a 16-month-old girl with a primary endodermal sinus tumor (EST) of the parotid gland. The girl was admitted to the hospital with a left side cervical tumor with a quick growth (within 3 wk). The tumor was surgically resected. The gross examination showed a 7.0-cm hemorrhagic and fragmentized mass. Diagnosis of an EST was established on the hematoxylin and eosin-stained slides from the resected material. Elevated serum alpha-fetoprotein (AFP) levels were detected and follow-up examinations of the patient did not show ESTs in other locations or other manifestations due to the tumor. The patient received chemotherapy after the surgery and remained alive without evidence of disease at the time of this writing (2 years after the diagnosis). As far as we know, this is the second report in the literature of a parotid gland's EST.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1983

Synthesis of serum proteins by cultures of chick embryo yolk sac endodermal cells.

Endodermal cells were isolated from yolk sacs of 3-day chick embryos and cultured for 6 days in Eagle's minimal essential media plus 10% fetal calf serum. During this period cells rapidly lost their ability to synthesize DNA as judged by [3H]thymidine incorporation into DNA. In spite of this loss of DNA synthesis serum protein synthesis and secretion remained at a constant 45% of total protein synthesis and secretion. This was determined by immunoprecipitation of culture media using antibodies directed against embryonic chick serum proteins. Media were also analyzed for the synthesis and secretion of specific serum proteins using polyacrylamide gel electrophoresis. The relative synthesis and secretion of the individual serum proteins followed that previously observed in ovo with the exception of alpha-globulin-a which became undetectable. When culture media were supplemented with ovalbumin or insulin the relative synthesis and secretion of certin specific serum proteins were altered. However, analysis of these same media samples showed that the total amounts of serum protein synthesis and secretion were unaffected.

Animals↗
PubMed1987

Neuron-like derivatives of cultured F9 embryonal carcinoma cells express characteristics of parietal endoderm cells.

Murine F9 embryonal carcinoma cells exposed to retinoic acid and dibutyryl cyclic AMP gradually arborize and acquire a neuron-like morphology in monolayer culture. Whether F9 cells can be induced to differentiate into cells with features specific to neural cells is controversial. We analyzed the intermediate filament content and pericellular matrix proteins of F9 cells after exposing them to retinoic acid, dibutyryl cyclic AMP, and nerve growth factor. In long-term cultures, a great majority of the cells appeared neuron-like, but showed intra- and pericellular laminin and type IV collagen, and frequently cytokeratin filaments as well. Several monoclonal antibodies to neurofilaments did not react with these cells in immunofluorescence or immunoblotting, though they recognize either all or individual mouse neurofilament triplet proteins. Polyclonal antibodies to neurofilament proteins gave a diffuse, nonfibrillar, vinblastine-resistant fluorescence in the morphologically neuron-like cells, but in immunoblotting failed to reveal polypeptides compatible with neurofilament triplet proteins. In long-term cultures, most of the cells appeared to have partially or totally lost the intermediate filaments. This was confirmed with anti-IFA antibodies which normally react with all intermediate filament proteins. The F9-derived cells did not respond to nerve growth factor in any detectable way. We conclude that the morphologically neuron-like derivatives of F9 cells display characteristics of modified parietal endoderm-like cells and do not show unequivocal features of neural cells.

Animals↗
PubMed1988

Expression of c-fos antisense RNA inhibits the differentiation of F9 cells to parietal endoderm.

To test the putative role of c-fos in F9 differentiation, we have attempted to inhibit c-fos expression in these cells using an SV40-based expression vector (pSVneo-sof) that programs expression of c-fos antisense (sof) sequences as a 3' extension of a neo mRNA transcript. Of six G418-resistant clones isolated in transfection experiments, five expressed neo-sof transcripts. Two clones synthesized polyadenylated mRNA of the expected size (3.8 kb), two were smaller than expected, and one was larger. Two clones that expressed reduced levels of c-fos protein were inhibited in the induction of laminin, type IV collagen, and proteoglycan-19 RNA transcripts measured after 4 days of differentiation induction with RA and dibutyryl cyclic AMP. Also inhibited was the induction of the differentiation markers, TROMA-1 and TROMA-3. Antisense-expressing cells were not inhibited in the differentiation pathway to visceral endoderm since the alpha-fetoprotein gene was activated normally. We conclude that c-fos antisense expression inhibits some aspects of differentiation in F9 cells.

Bucladesine↗
PubMed1991

Endoderm-specific expression of the Drosophila mex1 gene.

The Drosophila mex1 gene is one of several genes clustered within a 10-kb interval of polytene region 71CD that includes the ecdysone-regulated Eip28/29 gene. mex1 is expressed in several developmental stages, with gene transcripts accumulating initially in 9- to 12-hr embryos. During embryogenesis, mex1 exhibits an endoderm-specific pattern of expression. mex1 transcripts are first detected in the anterior and posterior midgut primordia of stage 12 embryos; subsequently, mex1 mRNA accumulates solely in the differentiating embryonic midgut. DNA sequence analysis reveals that the mex1 gene encodes an unusual cysteine-rich polypeptide.

Amino Acid Sequence↗
PubMed1983

Effect of the structural components of basement membranes on the attachment of teratocarcinoma-derived endodermal cells.

The effect of biochemically purified basement membrane components as mediators of cell attachment is studied in vitro using an endodermal PYS-2 cell line known to produce a basement membrane-like insoluble matrix. Fibronectin is shown to be as effective as laminin as an attachment-promoting protein, although the latter is a major product of these cells and the former is not produced by them in any detectable amount. Fibronectin also increases the attachment of the cells to type IV collagen-coated plates, but laminin lacks this effect. Protein synthesis-blocking agents such as cycloheximide totally abolish the attachment-promoting effect of extracellularly supplied laminin, but not that of extracellular fibronectin. Type IV collagen alone is no better a substratum for these cells than type I collagen or the plastic surface of the dish itself. The importance of an intact tertiary structure for the attachment is obvious in the case of both fibronectin and laminin. Denatured molecules or smaller fragments of these molecules do not promote cell attachment.

Animals↗
PubMed1984

Clonal tumorigenic endodermal cell lines producing basement membrane components.

Tumors were developed from the mouse teratocarcinoma-derived endodermal cell line PF HR-9 by subcutaneous injections in syngeneic mice of large numbers of cells previously cultured for several years at high cell density. Cell cultures were established from the tumors and the cells were cloned. The cloned sublines were highly malignant in vivo and tumor metastases were occasionally observed. The tumors contained abundant extracellular material, which was distinctly laminated and contained type IV collagen, laminin, and heparan sulfate proteoglycan. The tumorigenic sublines were also shown to have retained markers of the original cells, such as the cytoskeletal proteins Endo A and B. These cell lines should be useful for biosynthetic studies on basement membrane and cytoskeletal components and the tumors for isolation of these macromolecules and their mRNAs.

Animals↗
PubMed1983

Calcium-independent adhesion of extra-embryonic endoderm cells from the early chick blastoderm is inhibited by the blastoderm beta-D-galactoside-binding lectin and by beta-galactosidase.

Extra-embryonic endoderm cells from gastrulating chick embryos possess Ca2+-dependent and Ca2+-independent adhesive mechanisms. These cells also contain an endogenous beta-D-galactoside-binding lectin and cell surface receptors bearing galactose groups. The endogenous lectin inhibits cellular adhesion. To test whether the adhesive interactions involving lectin and galactose molecules are part of the Ca2+-independent or Ca2+-dependent adhesive mechanism, dissociated cells which were preincubated in beta-galactosidase were allowed to aggregate in the presence and absence of Ca2+ ions. Significant decreases in adhesion were observed in both cases. Cells were also allowed to aggregate in the presence and absence of Ca2+ ions when blastoderm lectin was present in the medium. Adhesion was decreased in both cases. The results suggest that cell surface galactose groups and the beta-D-galactoside-binding lectin are involved in Ca2+-independent adhesion.

Animals↗
PubMed1984

Serological characterization of a pluripotent mouse embryonal stem cell line, two transformed derivatives, and an endoderm-like cell line.

The pluripotent mouse embryonal stem cell line BLC 1 and two transformants derived from it by DNA transformation (T1 and T2/K26) as well as the blastocyst-derived cell line BLC 3 were tested for the presence of cell surface antigens recognized by the monoclonal antibodies ECMA-7, anti-SSEA-1 and M 1/22.25, and intermediate filament proteins labeled by the monoclonal antibodies TROMA 1 and TROMA 2 using a three-step indirect immunofluorescence technique. According to present concepts and in agreement with previous data (Wobus et al., 1984a), the results obtained indicate that BLC 1, T1 and T2/K26 are undifferentiated embryonal stem cells, and BLC 3 is an endoderm-like cell line.

Animals↗