A clinical case of mesenchymal iris dysplasia for the first time in a family

Frank-Kamenetsky syndrome is a rather rare ocular anomaly, which is characterized by hypoplasia of the iris stroma with exposure of its pigment layer and the development of secondary glaucoma, more often in the 2-3rd decade of life. Gonioscopy reveals goniodysgenesis in the form of "dentate" and anterior attachment of the root of the iris of a dirty gray color, as well as the inclusion of mesodermal tissue in the trabecular zone. The severity of the course of glaucoma is determined by the age of onset and is often malignant, gradually leading to blindness. Frank-Kamenetsky syndrome is observed in men and refers to a recessive disease linked to the X chromosome. The article presents a clinical case of mesenchymal iris dysplasia, first identified in a family, similar to the clinical picture of Frank-Kamenetsky syndrome. Previously, retinal pigment degeneration was observed in the male line of the family. Key words: Frank-Kamenetsky syndrome, glaucoma, congenital glaucoma.

Sox2 levels configure the WNT response of epiblast progenitors responsible for vertebrate body formation

WNT signalling has multiple roles. It maintains pluripotency of embryonic stem cells, assigns posterior identity in the epiblast and induces mesodermal tissue. We provide evidence that these distinct functions are conducted by the transcription factor SOX2, which adopts different modes of chromatin interaction and regulatory element selection depending on its level of expression. At high levels, SOX2 acts as a pioneer factor, displacing nucleosomes from regulatory elements with high affinity SOX2 binding sites and recruiting the WNT effector, TCF/β-catenin, to maintain pluripotent gene expression. Reducing SOX2 levels destabilises pluripotency and reconfigures SOX2/TCF/β-catenin occupancy to caudal epiblast expressed genes. These contain low-affinity SOX2 sites and are co-occupied by T/Bra and CDX. The loss of SOX2 allows WNT induced mesodermal differentiation. These findings define a role for Sox2 levels in dictating the chromatin occupancy of TCF/β-catenin and reveal how context specific responses to a signal are configured by the level of a transcription factor.

Mixoid Liposarcoma

Abstrak Sarkoma adalah pertumbuhan maligna jaringan mesodermal (jaringan ikat, otot, tulang). Liposarkoma adalah tumor ganas atau kanker pada jaringan lemak, yang biasanya dicirikan oleh adanya diferensiasi abortif sel – sel menjadi liposit dan merupakan tipe yang paling umum dari sarkoma jaringan lunak, muncul perlahan, membesar, tanpa rasa sakit, massa submukosa nonulserasi pada usia paruh baya. Jika terdeteksi lebih dini maka angka keberhasilan pengobatan menjadi lebih baik. Wide eksisi tumor merupakan modalitas pilihan pada penatalaksanaan Liposarkoma. Diagnosis ditegakkan berdasarkan riwayat perjalanan penyakit, pemeriksaan fisik dan pemeriksaan patologi anatomi. Dilaporkan satu kasus laki-laki berusia 74 tahun dengan diagnosis Miksoid Liposarkoma dilakukan Wide Eksisi Tumor tanpa pemberian Neo Adjuvan Terapi terlebih dahulu menunjukan perbaikan yang cukup signifikan Kata kunci: Sarkoma, Miksoid Liposarkoma, Wide Eksisi Tumor, Neo Adjuvan Terapi AbstractSarcoma is the growth of malignancy mesodermal tissue (connective tissue, muscle, bone). Liposarcoma is malignant tumor or cancer at fatty tissue, characterized by abortif differentiated cells to lipocyte and the common type of soft tissue sarcoma, appearing slowly, enlarged, painless, nonulceratif mass submucosal at the middle age. If the early detected the cure rate can be better. Wide Excision Tumor is the modality for treatment of Liposarcoma. The clinical diagnosis is made based on history of illness, physical examination and anatomical pathology examination. Reported One case, man 74 year old, diagnosed with Mixoid Liposarcoma treated by Wide Excision Tumor without given Neo Adjuvan Theraphy before showed a significant improvement. Keywords: Sarcoma, Mixoid Liposarcoma, Wide Eksisi Tumor, Neo Adjuvan Theraphy.

Development of the pericarp, septa and zone of dehiscence in the fruit of Cassia tora L.

The pod of <em>Cassia tora</em> is the product of a single carpel consisting of 20-30 seeds enclosed one in each compartment formed by the ingrowth of the endocarpic tissue. There are three distinct histological zones of the pericarp Epicarp (a), Mesocarp (b) and Endocarp (c). The paracytic stomata and uniseriate multicellular trichomes are found only in the outermost layer of the epicarp. The epicarp is single layered. The outer mesocarp in later stages of its development has many collenchyma, particularly at dorsal and ventral margins. The mesocarp develops from the homogenous mesodermal tissue of the ovary wall. The middle mesocarpic tissue becomes sclerenchymatous above the :main bundles providing rigidity at the two sutures where the zones of dehiscence develop inbetween them. The endocarp develops from the inner epidermis and 2-3 hypodermal layers. Due to frequent periclinal and anticlinal divisions and enlargement of the cells in the inner hypodermal layers, the septa are formed which never fuse; thus the so called compartment of the seed is not completely closed and the seeds slide off on separation of the valves. The inner hypodermal layers form the band of sclerenchyma above the septal cells. The inner margins without septa and sclerenchyma provide easy opening of the two valves from the chamber side.

Mesoderm induction in Xenopus is a zygotic event regulated by maternal VegT via TGFbeta growth factors

The maternal transcription factor VegT is important for establishing the primary germ layers in Xenopus. In previous work, we showed that the vegetal masses of embryos lacking maternal VegT do not produce mesoderm-inducing signals and that mesoderm formation in these embryos occurred ectopically, from the vegetal area rather than the equatorial zone of the blastula. Here we have increased the efficiency of the depletion of maternal VegT mRNA and have studied the effects on mesoderm formation. We find that maternal VegT is required for the formation of 90% of mesodermal tissue, as measured by the expression of mesodermal markers MyoD, cardiac actin, Xbra, Xwnt8 and alphaT4 globin. Furthermore, the transcription of FGFs and TGFbetas, Xnr1, Xnr2, Xnr4 and derriere does not occur in VegT-depleted embryos. We test whether these growth factors may be endogenous factors in mesoderm induction, by studying their ability to rescue the phenotype of VegT-depleted embryos, when their expression is restricted to the vegetal mass. We find that Xnr1, Xnr2, Xnr4 and derriere mRNA all rescue mesoderm formation, as well as the formation of blastopores and the wild-type body axis. Derriere rescues trunk and tail while nr1, nr2 and nr4 rescue head, trunk and tail. We conclude that mesoderm induction in Xenopus depends on a maternal transcription factor regulating these zygotic growth factors.

Fibroblast growth factor is a direct neural inducer, which combined with noggin generates anterior-posterior neural pattern

Neural tissue in developing Xenopus embryos is induced by signals from the dorsal mesoderm. Induction of anterior neural tissue could be mediated by noggin, a secreted polypeptide found in dorsal mesoderm. We show that bFGF, a known mesoderm inducer of blastula staged ectoderm, induces neural tissue from gastrula stage ectoderm. The type of neural tissue induced by bFGF from stage 10.25 ectoderm is posterior, as marked by Hox B9 expression. When bFGF and noggin are combined on early gastrula stage ectoderm, a more complete neural pattern is generated and no mesodermal tissue is detected. Explants treated with noggin and bFGF elongate and display distinct anterior and posterior ends marked by otx2 and Hox B9 expression, respectively. Furthermore, treatment of early gastrula ectoderm with noggin and bFGF results in the induction of En-2, a marker of the midbrain-hindbrain junction and Krox 20, a marker of the third and fifth rhombomeres of the hindbrain. Neither of these genes is induced by noggin alone or bFGF alone at this stage, suggesting a synergy in anterior-posterior neural patterning. The response of later gastrula (stage 11–12) ectoderm to bFGF changes so that Krox 20 and En-2 are induced by bFGF alone, while induction of more posterior tissue marked by Hox B9 is eliminated. The dose of bFGF affects the amount of neural tissue induced, but has little effect on the anterior-posterior character, rather the age of the ectoderm treated is the determinant of the response. Thus, an FGF signal may account for posterior neural induction, and anterior-posterior neural patterning could be partly explained by the actions of noggin and FGF, together with the changing response of the ectoderm to these factors.

Expression and function of the homoeotic genes Antennapedia and Sex combs reduced in the embryonic midgut of Drosophila

Drosophila homoeotic genes control the formation of external morphological features of the embryo and adult, and in addition affect differentiation of the nervous system. Here we describe the morphogenetic events in the midgut that are controlled by the homoeotic genes Sex combs reduced (Scr) and Antennapedia (Antp). The midgut is composed of two cell layers, an inner endoderm and an outer visceral mesoderm that surround the yolk. Scr and Antp are expressed in the visceral mesoderm but not in the endoderm. The two genes are required for different aspects of the midgut morphogenesis. In Scr null mutant embryos the gastric caeca fail to form. Scr is expressed in the visceral mesoderm cells posterior to the primordia of the gastric caeca and appears to be indirectly required for the formation of the caeca. Antp is expressed in visceral mesoderm cells that overlie a part of the midgut where a constriction will form, and Antp null mutant embryos fail to form this constriction. An ultrastructural analysis of the midgut reveals that the visceral mesoderm imposes the constriction on the endoderm and the yolk. The mesodermal tissue contracts within the constriction and thereby penetrates the layer of the midgut endoderm. Microtubules participate in the morphological changes of the visceral mesoderm cells. The analysis of the expression of Scr in Antp mutant embryos revealed a case of tissue-specific regulation of Scr expression by Antp. In the epidermis, Antp has been shown to negatively regulate Scr, but it positively regulates Scr in the visceral mesoderm.

Analysis of competence: receptors for fibroblast growth factor in early Xenopus embryos

Xenopus ectodermal cells have previously been shown to respond to acidic and basic FGF by differentiating into mesodermal tissue. In the present study, ectodermal explants from Xenopus blastulae were shown to have high affinity binding sites for 125I-aFGF (Kd = 1.4 X 10(−10) M). The total number of sites, determined by Scatchard analysis, was 3 X 10(8) per explant (surface area of approximately 1 mm2). Two putative receptors of relative molecular mass 130,000 and 140,000 were identified by chemical crosslinking to 125I-aFGF. Both acidic and basic FGF, but not TGF beta 2, could compete for affinity labelling of these bands. The receptor density at the cell surface parallels the developmental competence of Xenopus animal pole cells to respond to FGF. Receptors are present at highest density in the marginal zone but are not restricted to cells in this region.

Isolation of potential vertebrate limb-identity genes

Forelimbs and hindlimbs of tetrapods have different morphological patterns. One plausible explanation for the difference is that the cells that give rise to the limbs differentially express genes which control their pattern of development. Amphibian limb regeneration is an excellent system to test this hypothesis, since the same ultimate morphology is attained in regeneration as through embryogenesis. Using a combination of homeobox probes and differential screening, I have isolated two newt genes which are differentially expressed in regenerating forelimbs and hindlimbs. One of these genes displays properties expected of a gene involved in controlling limb morphology, including expression in mesodermal tissue and constancy of expression upon transplantation. Based on sequence analysis, this gene appears to be homologous to a homeobox-containing gene previously isolated from frog and human libraries.