Flower Biology and Vascular Differentiation

2021 ◽  
pp. 163-176
Author(s):  
Roni Aloni
Keyword(s):  
Vascular Differentiation ◽  
Flower Biology

Growth and Development of the Wheat Tiller. II. The Dynamics of Tiller Growth

1975 ◽  
Vol 23 (5) ◽  
pp. 745 ◽  
Author(s):  
RF Williams ◽  
RHM Langer
Keyword(s):  
Negative Correlation ◽  
Growth And Development ◽  
Critical Event ◽  
Vascular Differentiation ◽  
Strong Negative Correlation ◽  
Physical Constraints ◽  
Size Dependent ◽  
Bud Growth ◽  
Time Relation ◽  
Tiller Bud

From an analysis of the length-time relation for tiller growth in wheat it was concluded that tillers which emerged traced a discontinuous curve, and that the discontinuity marked a critical event in tiller growth. Tiller buds which did not emerge as tillers continued to grow even more slowly, at least until anthesis of the primary shoot. The critical event was identified as that of escape from the cavity in which the bud was tightly contained throughout early development. The timing of vascular differentiation in tiller buds was shown to be size-dependent and there was no evidence for any correlation with the critical event of escape. A strong negative correlation between the lengths of the 3rd tiller buds and their subtending internodes was established, and the presence or absence of the 4th tiller bud was also correlated with its internode length. Current hypotheses relating to apical dominance are reviewed, and it is suggested that the dynamic physical constraints implicit in tiller bud growth add a further complication. It was concluded that hormonal, nutritional and constraint mechanisms need to be integrated as partial mechanisms which interacted at the interfaces between successive levels within apical systems.

scholarly journals Description of Flower Biology of Under-Exploited Species, <i>Zingiber barbatum</i> (Wall.) from Myanmar

2020 ◽  
Vol 11 (07) ◽  
pp. 1031-1048
Author(s):  
Musavvara Kh. Shukurova ◽  
Daisy Myint ◽  
Syed Abdullah Gilani ◽  
Kazuo N. Watanabe
Keyword(s):  
Flower Biology

Primary vascular patterns in root meristems of Pontederia cordata and their relevance to studies of root development

1980 ◽  
Vol 58 (12) ◽  
pp. 1351-1369 ◽  
Author(s):  
W. A. Charlton
Keyword(s):  
Apical Meristem ◽  
Vascular System ◽  
Root Apex ◽  
Root Apical Meristem ◽  
Vascular Pattern ◽  
Quiescent Centre ◽  
Vascular Differentiation ◽  
Pontederia Cordata ◽  
Distribution Of Components ◽  
Root Apices

There are several files of metaxylem cells in root apices of Pontederia cordata L., each considered to consist of a series of prospective vessels with their ends in contact. Two longitudinally adjacent vessels may be in the same file of cells produced by the root apex or in adjacent files. As the root grows, successive prospective vessels are added to the apical ends of most of the files but not all files are continued. Addition of prospective vessels appears to take place within the "quiescent centre" of the root apical meristem. Where files are not continued there is no immediate readjustment of remaining files. The longitudinal and transverse distribution of components of the vascular system (including protophloem and protoxylem) is discussed in relation to the means by which the pattern of development may be controlled. Rates of production of vessels and the final lengths of the vessels are estimated. The observations and deductions are discussed in relation to other studies of root growth, vascular differentiation, and vascular pattern formation and maintenance.

Congenital Supratentorial and Infratentorial Peripheral Neurogenic Tumor: A Clinical, Ultrastructural, and Immunohistochemical Study

Neurosurgery ◽  
1986 ◽  
Vol 19 (3) ◽  
pp. 426-433 ◽  
Author(s):  
David S. Moss ◽  
Stephen J. Haines ◽  
Arnold S. Leonard ◽  
Louis P. Dehner
Keyword(s):  
Spindle Cell ◽  
Immunohistochemical Study ◽  
Operative Procedure ◽  
Cranial Nerves ◽  
Vascular Differentiation ◽  
Spindle Cell Neoplasm ◽  
Nerve Sheath ◽  
Neuroectodermal Tumors ◽  
The Central Nervous System ◽  
Supratentorial Mass

Abstract Congenital neoplasms of the central nervous system are extremely rare, although they have been well documented since the earliest reports from the mid-19th century. Medulloblastoma, other primitive neuroectodermal tumors, and various types of gliomas have comprised the majority of cases. This report describes a highly unusual infratentorial and supratentorial tumor presenting as a scalp mass in a neonate who experienced in utero distress. The supratentorial mass extended through a defect in the skull to the parietooccipital lobe, and the infratentorial aspect involved the 9th and 10th cranial nerves in the region of the cerebellopontine angle. A complex spindle cell neoplasm incorporating peripheral nerve sheath and vascular characteristics was further characterized by electron microscopy and immunohistochemistry. Based upon these studies, the tumor was interpreted as a congenital schwannoma with divergent vascular differentiation. The child has been tumor-free for approximately 2 years after the initial operative procedure.

Ephrin receptor, EphB4, regulates ES cell differentiation of primitive mammalian hemangioblasts, blood, cardiomyocytes, and blood vessels

Blood ◽  
2004 ◽  
Vol 103 (1) ◽  
pp. 100-109 ◽  
Author(s):  
Zhengyu Wang ◽  
Kenneth Cohen ◽  
Ying Shao ◽  
Pamela Mole ◽  
David Dombkowski ◽  
...  
Keyword(s):  
Es Cells ◽  
Embryonic Stem ◽  
Mesoderm Induction ◽  
Es Cell ◽  
Vascular Differentiation ◽  
Phenotypic Characteristics ◽  
Coordinated Development ◽  
Modifying Factors ◽  
Ephrin Receptors ◽  
Ephrin Receptor

Abstract Differentiation of pluripotent embryonic stem (ES) cells is associated with expression of fate-specifying gene products. Coordinated development, however, must involve modifying factors that enable differentiation and growth to adjust in response to local microenvironmental determinants. We report here that the ephrin receptor, EphB4, known to be spatially restricted in expression and critical for organized vessel formation, modifies the rate and magnitude of ES cells acquiring genotypic and phenotypic characteristics of mesodermal tissues. Hemangioblast, blood cell, cardiomyocyte, and vascular differentiation was impaired in EphB4–/– ES cells in conjunction with decreased expression of mesoderm-associated, but not neuroectoderm-associated, genes. Therefore, EphB4 modulates the response to mesoderm induction signals. These data add differentiation kinetics to the known effects of ephrin receptors on mammalian cell migration and adhesion. We propose that modifying sensitivity to differentiation cues is a further means for ephrin receptors to contribute to tissue patterning and organization.

VASCULAR DIFFERENTIATION OF STEM CELLS BY MECHANICAL FORCES

2010 ◽  
pp. 247-269 ◽  
Author(s):  
TIMOTHY M. MAUL ◽  
ALEJANDRO NIEPONICE ◽  
DAVID A VORP
Keyword(s):  
Stem Cells ◽  
Mechanical Forces ◽  
Vascular Differentiation

Pediatric Angiosarcoma of Soft Tissue: A Rare Clinicopathologic Entity

2010 ◽  
Vol 134 (3) ◽  
pp. 481-485 ◽  
Author(s):  
Lobna Ayadi ◽  
Abdelmajid Khabir
Keyword(s):  
Spindle Cell ◽  
Immunohistochemical Study ◽  
Kaposi Sarcoma ◽  
Neck Region ◽  
Epithelioid Hemangioendothelioma ◽  
Vascular Tumors ◽  
Clinical Settings ◽  
Vascular Differentiation ◽  
Head And Neck Region ◽  
Poorly Differentiated

Abstract Angiosarcomas are rare tumors that predominantly affect adults and elderly patients. Although angiosarcomas are well described in a variety of clinical settings, they have been poorly studied in children and little is known about their biology, natural history, or optimal treatment. Childhood angiosarcomas are exceedingly rare. The head and neck region and mediastinum seem to be the preferred locations. Most tumors are high-grade tumors. Vasoformative architecture is not always obvious on light microscopy requiring the benefit of immunohistochemical study. The differential diagnosis includes Kaposi sarcoma, epithelioid hemangioendothelioma, hemangiopericytoma, and spindle cell hemangioendothelioma whose prognosis is different. Complete resection is required for patients with localized tumors. Malignant vascular tumors are rare in children in the first 2 decades of life and when they do occur they seem to be more aggressive than in adults. Pathologic diagnosis is difficult particularly in poorly differentiated angiosarcomas requiring immunohistochemical study to confirm vascular differentiation.

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