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PubMed1998

Vasculogenesis from embryonic bodies of murine embryonic stem cells transfected by Tgf-beta1 gene.

Mouse embryonic stem (ES) cells transfected with a 1.7 kb cDNA of porcine transforming growth factor type beta1 (TGFbeta1), known as ES-T cells, were found to be able to differentiate in vitro into cystic embryonic bodies (EBs) with outspread tubular structures. Morphological analysis using light, phase-contrast and electron microscopes revealed that in culture, the EBs of ES-T cells initially developed some flat endothelial-like cells which further proliferated and migrated to form thread structures. At 8-10 days after EB formation, these thread structures further developed into net-like and tubular structures connecting directly to EBs. Immunofluorescent assays using antibodies against Flk-1 and von Willebrand factor (vWF) indicated that these net-like and tubular structures of ES-T cells consisted of vascular endothelial cells. Further analysis by RT-PCR revealed that the EBs with tubular structures expressed the mRNA of other markers of vascular endothelial cells, including VE-cadherin and platelet-endothelial cell adhesion molecule (PECAM). Cells of hematopoietic origin were not detected on the outside of EBs by immunostaining using several antibodies specific for granulocytes, macrophages and lymphocytes as well as by benzidine staining for erythroid cells on the outside of EBs. Our data demonstrates that the transfer of TGFbeta1 into ES cells results in a significant vasculogenesis without concomitant hematopoiesis. ES-T cells could therefore provide an excellent model for studying blood vessel formation and vasculogenic and hematopoietic interactions.

Animals↗
PubMed1999

The thebesian circulation to developing conducting tissue: a nutrient-nodal hypothesis of cardiogenesis.

BACKGROUND: In a previous paper the authors suggested that the right atrial appendage is structured for retrograde sinusoidal blood flow to embryonic conducting tissue in the venous sinus portion of the right atrium. OBJECTIVE: To test the hypothesis that the relationship among conducting, valvar and trabecular myocardium of the human heart is primarily for the nutrition of the heart itself rather than for downstream blood flow. MATERIAL AND METHODS: Embryonic, fetal, infant and adult human hearts were studied grossly and microscopically for evidence of a dedicated sinusoidal blood supply to the atrioventricular node. Outflow tract anatomy was reviewed to test the hypothesis that junctional zones, nodal or non-nodal, are structured according to the same basic principle concerning nutrient supply to conducting tissue. CONCLUSIONS: The finding of a sinusoid-rich 'spongy trabecula' in relation to the septal node suggests that the septal junctional zone, like the sinoatrial junctional zone, is structured for retrograde sinusoidal blood flow to nodal conducting tissue. The anatomy of the pulmonary and aortic outflow tracts supports the idea that the heart is structured from repeating triplets of conducting, valvar and sinusoid-rich trabeculae. Although the heart is an external pump, it is structured as an internal pump.

Adult↗
PubMed1975

[A heterologous mesodermal tumor of the uterus of the pleomorphic rhabdomyosarcoma type].

In the available literature mesodermal tumours of the uterus are described under various names (botryoid sarcoma, carcinocarcoma, chondrosarcoma, rabdomyosarcoma, etc.). For the sake of unification of terminology of these tumours, Kehrer suggested the term "mesodermal mixed tumours", thereby reflecting their origin from cellular elements of the mesoderma. Histologically, benign and malignant variants of tumours are identified; these tumours are characterized by multi-component composition of tissues forming integral parts thereof, the latter may be homologous or heterologous. Clinically, the said tumours are diagnosed in rare cases. Diagnosis is made on the basis of a microscopical investigation of a scrape from the uterine cavity, or investigation of the operation material. Heterologic tumours of the uterus of the type of rabdomyosarcoma have been described by a number of authors. As to their microscopical structure, they may be divided into embryonal, alveolar and pleomorphous. A case of heterologic mesodermal tumour, verified as a pleomorphous rabdomyosarcoma, which could develop in a long existed mesodermal tumour of the uterus in a woman 67 years of age, is described.

Aged↗
PubMed2003

Lsh-deficient murine embryonal fibroblasts show reduced proliferation with signs of abnormal mitosis.

Genomic hypomethylation and chromosomal instability are frequent characteristics of human cancer cells. Targeted deletion of Lsh leads to a global defect in genomic methylation, and Lsh-deficient mice die at birth with a reduced body weight. Here, we examine the growth pattern of embryonal fibroblasts derived from Lsh-/- mice. The absence of Lsh leads to a severe proliferative defect of fibroblasts with lower saturation density, early signs of senescence, and a lower frequency of immortalization. The impaired growth rate in vitro may be in part responsible for the small size of Lsh-deficient mice. In addition, Lsh-/- fibroblasts accumulated high centrosome numbers, formed multipolar spindles, displayed micronuclei formation, and elevated nuclear DNA content. A similar increase in centrosome abnormalities was observed when wild-type fibroblasts were treated with a DNA-demethylating agent, suggesting that genomic hypomethylation plays an important role in mitotic defects of Lsh-/- murine embryonal fibroblasts, possibly by altering chromatin structure. Because supernumerary centrosomes are a common feature in cancer cells, this Lsh-dependent pathway has the potential to contribute to genetic instability and chromosomal aberrations during tumor progression.

Animals↗
PubMed1992

Arteriovenous malformation of the hand: a case study.

Arteriovenous malformations (AVMs) are complex congenital vascular anomalies resulting from faulty embryonic development of arterial and venous structures. The present discussion will specifically address AVMs of the extremities. Complications of these lesions can include tissue damage, functional impairment and amputation. The article reviews current diagnostic procedures and treatment options. A case study is presented with a discussion of nursing care focusing on pain, anxiety, and alteration in peripheral tissue perfusion.

Adult↗
PubMed2004

[Expression characteristics of transforming growth factor-beta1 in human skin at different development stages of gestation].

OBJECTIVE: To investigate gene expression of transforming growth factor-beta(1) (TGF-beta(1)) and its two upstream signalling factors (smad2 and smad3) in fetal skin at different gestational ages and postnatal skin and its potential biological significance. METHODS: Fetal skin samples of human embryo were obtained from spontaneous abortions at different gestational ages ranging from 13 to 32 weeks, and also skin collected from patients undergoing plastic surgery. After morphological characteristics of skin at different developmental stages were examined histologically, gene expressions of TGF-beta(1), smad2 and smad3 in skin specimens at different developmental stages were examined with reverse transcription-polymerase chain reaction analysis (RT-PCR). RESULTS: Gene expression of TGF-beta(1), smad2 and smad3 could all be detected in fetal skin and skin after birth. In skin from early gestational fetus, gene expressions of TGF-beta(1) and smad2 were weak. Along with advance in gestational age, gene expression of these two genes in skin became progressively stronger. In skin from late gestational fetus and skin after birth, the transcription contents of these two genes were significantly increased compared with early gestation fetus (P<0.05). On the contrary, gene expression of smad3 was apparently higher in younger fetal skin versus elder compared with that of late fetal skin (P<0.05). In skins after birth, the levels of smad3 gene expression were elevated to the level similar to that in early gestational fetal skin. CONCLUSION: The signal pathway mediated by TGF-beta(1) might be involved in regulating development of the skin at embryonic stage and in designating cetaceous structure and function, and also in wound healing after birth. The relative lack in expression of TGF-beta(1) and smad2 genes in skins from younger fetuses might contribute to fetal scar-less healing, in which the role of smad3 needs to be further investigated.

Actins↗
PubMed2004

[Confocal microscopy: a tool to visualise differentiation of stem cells into cardiomyocytes].

Confocal microscopy offers important advantages compared to conventional epifluorescence microscopy. It works as an "optical microtome" leading to a accurate image resolution of a defined focal plane. Furthermore, the addition of a Nipkow disk on the confocal microscope greatly accelerates the image acquisition, up to 30 frames per second. Nevertheless, the software-assisted mathematical restoration of images acquired using a wide-field microscope allows to get images with a resolution similar to the one obtained in confocal microscopy. These imaging technologies allowed us to monitor on line cardiac differentiation of murine embryonic stem (ES) cells within 3D structures called embryoid bodies. The high rate acquisition of images using the confocal microscope equipped with a Nipkow disk allows to monitor calcium spiking in differentiating cardiomyocytes within embryoid bodies.

Animals↗
PubMed1991

Molecular and functional analysis of human natural killer cell-associated neural cell adhesion molecule (N-CAM/CD56).

The neural cell adhesion molecule (N-CAM/CD56) is a member of the Ig supergene family that has been shown to mediate homophilic binding. Several isoforms of N-CAM have been identified that are expressed preferentially in different tissues and stages of embryonic development. To examine the primary structure of N-CAM expressed in leukocytes, N-CAM cDNA were generated by polymerase chain reaction from RNA isolated from normal human NK cells and the KG1a hematopoietic leukemia cell line. The sequence of leukocyte-derived N-CAM cDNA was essentially identical with N-CAM cDNA from human neuroblastoma cells that encode the 140-kDa isoform of N-CAM. Inasmuch as N-CAM is preferentially expressed on human NK cells and a subset of T lymphocytes that mediate MHC-unrestricted cell-mediated cytotoxicity, we examined the potential role of N-CAM in cell-mediated cytotoxicity and heterotypic lymphocyte-tumor cell adhesion. N-CAM loss mutants were established from the human N-CAM+ KG1a leukemia cell line, and N-CAM cDNA was transfected into a human colon carcinoma cell line and murine L cells. Using this panel of mutants and transfectants, it was determined that expression of N-CAM on these target cells does not affect susceptibility to resting or IL-2-activated NK cell-mediated cytotoxicity. Moreover, expression of N-CAM in these transfectants failed to induce homotypic or heterotypic cellular adhesion. Collectively, these studies indicate that homophilic N-CAM interactions probably do not mediate a major role in the cytolytic interaction between NK cells and N-CAM+ tumor cell targets.

Antigens, CD↗
PubMed1990

Ciliated hepatic foregut cyst. A mucus histochemical, immunohistochemical, and ultrastructural study in three cases in comparison with normal bronchi and intrahepatic bile ducts.

We describe herein the morphologies of three cases of ciliated hepatic cysts and compare them with those of normal bronchi and intrahepatic bile ducts. Grossly, the hepatic cysts were located in the subcapsular region. They were solitary, unilocular, and rather small (less than 4 cm in diameter). Histologically, the cyst wall consisted of four layers: pseudostratified ciliated columnar epithelia with mucous cells, subepithelial connective tissue, smooth-muscle bundles, and an outermost fibrous capsule. The epithelial cytoplasm contained neutral, carboxylated, and sulfated mucus. We noted moderate immunoreactivity to keratin, epithelial membrane antigen, carcinoembryonic antigen, DU-PAN-2 and secretory component; weak immunoreactivity to cytokeratin CAM 5.2, cytokeratin AE1 + 3, and carbohydrate antigen 19-9; and faint or negative immunoreactivity to IgA and IgM. Cilia were immunoreactive to actin and tubulin; smooth muscles were immunoreactive to actin and desmin. Ultrastructural observations revealed definite cilia arranged in a 9 + 2 pattern as well as mucous cells. These morphologic features of the hepatic cysts were similar to those of normal bronchi but different from those of normal bile ducts. Our findings suggest that ciliated hepatic cysts arise from the embryonic foregut and differentiated toward bronchial structures in the liver.

Adult↗
PubMed1989

The reconstruction principle.

The theory of epigenesis is the undisputed paradigm of embryology, and it is still based on the classical concept proposed by Aristotle: the idea that embryonic development is a generation of structures which takes place according to a design--today we say a set of instructions--already present in the fertilized egg. This is a doctrine which can be referred to as 'pre-information', since it claims the preexistence of information exactly as the old theory of preformation claimed the preexistence of form. Here, however, it is shown that a more general version of epigenesis can be held, because of a new principle which states that it is mathematically possible to obtain not only a convergent generation of form, or structure, but also a convergent generation of information.

Animals↗
PubMed1989

[Clinico-morphologic research on the initial stage of open-angle glaucoma in patients of various ages].

The paper analyses results of clinical examination of patients with initial open-angle glaucoma--44 eyes of patients under 44 years of age and 96 eyes of patients above 50--and those of morphologic studies of 16 biopsies of the drainage zone of the eyes obtained at sinusotrabeculectomy in young and elderly patients. A complex investigation of the initial stage of open-angle glaucoma has shown identical clinico-morphologic changes responsible for this form of the disease in patients at any age. This identity is manifested itself by similar hydro- and blood microcirculatory disturbances, changes in the anterior chamber angle structures differing only quantitatively in patients of various age. Some distinctive peculiarities in the course of open-angle glaucoma are also noted in persons of young age. Morphologic studies have revealed qualitative differences in glaucomatous patients of young age, such as specific structures of collagenous fibers peculiar to embryonic period.

Adult↗
PubMed1988

Piebaldism, Waardenburg's syndrome, and related disorders. "Neural crest depigmentation syndromes"?

The striking parallel between the melanin pigmentary abnormalities of the hair and skin in piebaldism, Waardenburg's syndrome, piebaldism with deafness, and piebaldism or Waardenburg's syndrome with aganglionosis of the gut suggests that all these disorders belong to the same category. At present, the most logical way to link these syndromes is to consider them the results of defective development of the neural crest. The reason that in certain circumstances only melanoblasts are affected whereas in other situations other neural crest derivatives also are involved is not yet clear. In addition, some features, such as the upper limb abnormalities observed in Klein's syndrome, are not explained by a neural crest defect. Our knowledge of the interaction between the neural crest and neighboring structures closely related to it during embryonic life is limited. Some clues allowing us to better understand these complex syndromes combining depigmentation of hair and skin will come from future research in this field.

Animals↗
PubMed1985

[Study of atrial conduction tissue in the 17 mm V-C human embryo. Morphological contribution to the pathogenesis of sinoauricular node dysfunction].

Is there a specialised conduction pathway connecting the sinoatrial and atrioventricular nodes within the crista terminalis? As lesions of this zone can cause sinus node dysfunction and the sick-sinus syndrome, we decided to study this structure at the beginning of its embryonic development. Serial 10 micronthichness transverse sections of a 17 mm vertex-coccyx (Stage 19) human embryo were studied by light microscopy, anatomical reconstruction (Born) and morphometry. The region of the sinus venosus and venous valves, of the superior vena cava and the atrioventricular region were drawn and reconstructed with 150 X magnification by Born's method using wax plates of the following dimensions: 175 X 95X 1.5 mm. The volume of the region of the sino-atrial node was determined by multiplying the thickness of the sections by the surface of the region (measured by planimetry using the point counting method); its value was 15.4 X 10(6) microns3 with an antero-posterior diameter of 490,0 micron. These results show that this region is already proportionally larger in Stage 19 embryos. Reconstruction showed the sinoatrial node region to be a round bulge with a groove on either side: that of the sulcus terminalis and the superior vena cava on the left and the same vein with the mesocardium on the right. The right venous valve connects this zone with the interatrial septum and comprises two distinct cellular components, on derived from the atrial wall and the other from the muscle of the sinus venous. The artery fo the sinoatrial node was identified.(ABSTRACT TRUNCATED AT 250 WORDS)

Arrhythmias, Cardiac↗
PubMed1977

[Odontogenesis, organogenetic model in teratomas: crown formation].

Using the technique of 3 dimensional reconstruction, the various steps involved in the formation and growth of the crown of a tooth primordium observed in a complex ovarian teratoma have been compared with that occurring in dermoid cysts and in the normal dental system. Inside dermoid cysts, the characteristic form of the tooth is established during the production of the dentine and enamel and the process is often similar to that occurring during normal tooth development. In teratomas, however, organogenesis and morphogenesis take place within a system undergoing multidirectional development. They are dissociated during both the embryonic stage and that of a structural formation. Morphogenesis is the most disturbed and the role of the environment is presumably therefore very important.

Dermoid Cyst↗
PubMed1983

Development of responsiveness to glucocorticoid hormones.

Glucocorticoid (GC) hormones induce the activity of glutamine synthetase (GS) in the neural retina. This function of the hormone is mediated by the glucocorticoid receptors (GR), which upon binding the GC translocate from the cytosol to the nucleus, bind to specific acceptor sites in chromatin and evoke a differential increase in tissue-specific gene transcription, ultimately leading to high GS activity. The competence to respond to GC hormones is acquired in the neural retina of the chick embryo during the second week of embryogenesis. However, high levels of GRs, capable of translocating to the chromatin, are available to the retina at earlier stages of development. The mechanism(s) which endow the tissue with competence to respond to the hormonal signal are as yet unknown. Our studies were directed toward the elucidation of this biological phenomenon. We have shown that: (A) Acquisition of responsiveness is dependent on DNA synthesis and apparently requires a certain number of cell cycles before the cells gain competence to express this function. (B) Responsiveness is correlated with a loss of two-thirds of the specific cortisol binding sites, as shown by binding studies. We show that this is a developmental event which correlates with the age-dependent acquisition of responsiveness. This process requires the milieu of the intact cell (concentrated cytosol, 0.15 M KCl), and apparently reflects an early step in GR activation. The binding studies raised the working hypothesis that the GRs of the embryonic neural retina are heterogeneous in structure and function and react differently to the binding of the inducing ligand. The transformation of one GR form to the active regulator appears to be dependent on the inactivation (loss of binding) of another GR form acting as an inhibitory control unit. This working hypothesis is supported by studies on the molecular characterization of the GRs of the responsive retina: analytical polyacrylamide gel electrophoresis (PAGE) revealed that the GRs in the cytosol are dimers (or higher oligomers), made of nonidentical GR units; one of 108,000 Mr designated GR-B and another, not yet characterized, designated GR-X. GR-B is cleaved in the cytosol to the 61,000 Mr form designated GR-C. Isoelectric focusing of the unactivated, molybdate stabilized cytosol revealed two forms of inactive GRs, I and II. Activation (1 h at 30 degrees C, in the presence of [3H]-triamcinolone acetonide and 0.15 M KCl) inactivates GR-I (loss of binding) and transforms GR-II to a basic nuclear binding protein, GR-III. The formation of GR-III correlates with the inactivation of GR-I. GR-I is an acidic protein, sensitive to isotonic KCl, and may be equivalent to GR-X, which has to date eluded characterization by PAGE. (C) The expression of the cellular functions involved in acquisition of responsiveness to GC hormones is correlated with the withdrawal of the cortisol-target cells from cell cycling.

Animals↗
PubMed1984

[Comparison of a continuous infusion with a daily bolus injection of bleomycin in a heterotransplanted human testicular cancer].

Continuous Infusion vs. Bolus Injection of Bleomycin in a Human Testicular Cancer Xenograft System Bleomycin ( Bleomycinum Mack ) ranks among the most effective agents against non-seminomatous testicular cancer. The cytocidal effects of this drug are cell cycle dependent and increase with duration of exposure. Schedule dependency has been demonstrated in conventional murine tumor systems and recently superiority of continuous infusion over bolus injection has been claimed using the "Lewis lung carcinoma". The continuous infusion of bleomycin has found entry into many successful combination chemotherapy regimens without definitive proof of its superiority by a randomized clinical phase II trial. Presently, however, any clinical study comparing single agent activity in untreated patients with testicular cancer would meet ethical restrictions since combination chemotherapy affords cures in 30-80% of all cases. The human tumor xenograft model employing congenitally athymic (nu/nu) mice preserves salient features of the original tumor specimen with remarkable fidelity. Thus structural similarity at the microscopic level ("embryonal carcinoma with choriocarcinoma") and production of beta-HCG both in the donor patient and the subsequent xenograft line "Ma" could be demonstrated. The overall correlation between serum beta-HCG levels and tumor volumes was significantly positive (r = 0.85; p = 0.001), but varied among individual tumor-bearing mice. Covering a total dose range from 10.5-42 mg/kg given over 7 days no difference was found between daily bolus injections and continuous infusion of bleomycin. These data allow for the first time a direct comparison of both schedules of administration in a testicular cancer of human origin. On the basis of these findings the clinical preference for continuous administration of bleomycin is questioned, especially since it may cause considerable discomfort to the cancer patient.

Animals↗
PubMed1981

[Acid and alkaline phosphatases in the cerebellar structures in autosomal trisomy syndromes].

The activity of nonspecific phosphomonoesterases in cerebellar structure of newborns and infants with trisomies in the 13th (5 cases) 18th (4) and 21st (14) chromosomes was investigated. In all trisomies, changes of phosphatase activity in the cerebellar structures were demonstrated which were particularly marked with alkaline phosphatase. The activity of this enzyme increased not only in the vascular endothelium but in a number of cellular structures as well: in the external embryonal and internal granular layers of the cortex, in the nuclei of Purkinje cells and neurons of the nucleus dentatus, in the foci of heterotopia of cortical cells into the white matter and nucleus dentatus. In Edwards' syndrome the activity of alkaline phosphatase in cellular elements of the cerebellum was slightly higher than in the control group. Changes in the activity was observed in the cells of the external embryonal layer, neurons of the nucleus dentatus and in the cells of the heterotopic foci. In autosomal trisomies dystopic cells have dissimilar levels of phosphatase activity and stain mosaically which seems to confirm the assumption of their dissimilar differentiation.

Acid Phosphatase↗