scholarly journals Active Cell Divisions Generate Exotic Fourfold Orientationally Ordered Phase in Living Tissue

2021 ◽  
Author(s):  
Dillon J Cislo ◽  
Haodong Qin ◽  
Fengshuo Yang ◽  
Mark J Bowick ◽  
Sebastian J Streichan
Keyword(s):  
Cell Proliferation ◽  
Orientational Order ◽  
Subsequent Development ◽  
The Body ◽  
Equilibrium System ◽  
Physical Processes ◽  
Global Order ◽  
Cell Divisions ◽  
Complex Shapes ◽  
Extensive Growth

Morphogenesis, the process through which genes generate form, establishes tissue scale order as a template for constructing the complex shapes of the body plan. The extensive growth required to build these ordered substrates is fuelled by cell proliferation, which, naively, should destroy order. The active mechanisms that couple cellular and physical processes to generate and maintain global order, thereby reconciling this seeming contradiction, remain elusive. Using live imaging and tissue cartography, we quantitatively analyze the dynamics of fourfold tissue ordering in the crustacean Parhyale hawaiensis. We show that cell divisions are the main drivers of tissue flow leading to a fourfold orientationally ordered phase. Waves of anisotropic cell proliferation propagate across the embryo with precise choreography, such that defects introduced into the nascent lattice by cell divisions are healed by subsequent divisions through active defect climb. Orchestrating cell proliferation rates and orientations enables cell divisions to organize, rather than fluidize, the tissue. The result is a robust, active mechanism for generating global orientational order in a non-equilibrium system that sets the stage for the subsequent development of shape and form.

scholarly journals Extracellular-Vesicle-Based Coatings Enhance Bioactivity of Titanium Implants—SurfEV

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1445
Author(s):  
Taisa Nogueira Pansani ◽  
Thanh Huyen Phan ◽  
Qingyu Lei ◽  
Alexey Kondyurin ◽  
Bill Kalionis ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Titanium Surface ◽  
Wound Closure ◽  
Cell Types ◽  
Extracellular Vesicle ◽  
Tissue Growth ◽  
Titanium Implants ◽  
The Body ◽  
High Concentrations ◽  
And Migration

Extracellular vesicles (EVs) are nanoparticles released by cells that contain a multitude of biomolecules, which act synergistically to signal multiple cell types. EVs are ideal candidates for promoting tissue growth and regeneration. The tissue regenerative potential of EVs raises the tantalizing possibility that immobilizing EVs on implant surfaces could potentially generate highly bioactive and cell-instructive surfaces that would enhance implant integration into the body. Such surfaces could address a critical limitation of current implants, which do not promote bone tissue formation or bond bone. Here, we developed bioactive titanium surface coatings (SurfEV) using two types of EVs: secreted by decidual mesenchymal stem cells (DEVs) and isolated from fermented papaya fluid (PEVs). For each EV type, we determined the size, morphology, and molecular composition. High concentrations of DEVs enhanced cell proliferation, wound closure, and migration distance of osteoblasts. In contrast, the cell proliferation and wound closure decreased with increasing concentration of PEVs. DEVs enhanced Ca/P deposition on the titanium surface, which suggests improvement in bone bonding ability of the implant (i.e., osteointegration). EVs also increased production of Ca and P by osteoblasts and promoted the deposition of mineral phase, which suggests EVs play key roles in cell mineralization. We also found that DEVs stimulated the secretion of secondary EVs observed by the presence of protruding structures on the cell membrane. We concluded that, by functionalizing implant surfaces with specialized EVs, we will be able to enhance implant osteointegration by improving hydroxyapatite formation directly at the surface and potentially circumvent aseptic loosening of implants.

The Caenorhabditis elegans gene lin-44 controls the polarity of asymmetric cell divisions

Development ◽  
1994 ◽  
Vol 120 (5) ◽  
pp. 1035-1047 ◽  
Author(s):  
M.A. Herman ◽  
H.R. Horvitz
Keyword(s):  
Caenorhabditis Elegans ◽  
The Body ◽  
Body Axis ◽  
Nematode Caenorhabditis Elegans ◽  
Asymmetric Cell Divisions ◽  
Cell Divisions ◽  
Sister Cells

The generation and orientation of cellular and organismic polarity are fundamental aspects of development. Mutations in the gene lin-44 of the nematode Caenorhabditis elegans reverse both the relative positions of specific sister cells and the apparent polarities of these cells. Thus, lin-44 mutants appear to generate polar cells but to misorient these cells along the body axis of the animal. We postulate that lin-44 acts to specify the orientation of polar cells.

scholarly journals The body water compartments in women with preeclampsia in the peripartum period

2021 ◽  
Vol 17 (7) ◽  
pp. 20-23
Author(s):  
O.M. Klygunenko ◽  
O.О. Marzan
Keyword(s):  
Pregnant Women ◽  
Extracellular Fluid ◽  
Subsequent Development ◽  
Bioelectrical Impedance ◽  
Body Water ◽  
Fluid Volume ◽  
The Body ◽  
Severe Preeclampsia ◽  
Water Compartments ◽  
Total Fluid

Background. Preeclampsia in pregnant women is a threatening condition that causes significant water imbalance, particularly hyperhydration of the extracellular fluid compartment. The condition is the result of the main pathogenetic processes — endothelial dysfunction and the subsequent development of hypoproteinemia. The changes can be detected by measuring body water compartments. Objective: to investigate the effect of a standard intensive care on the body water compartment indicators in women with moderate to severe preeclampsia. Materials and methods. Ninety patients divided into three groups were examined: non-pregnant healthy women, pregnant women with healthy pregnancy, and women whose pregnancy was complicated by moderate to severe preeclampsia. Body water compartments were measured by non-invasive bioelectrical impedance analysis. Results. Pregnancy complicated by preeclampsia is accompanied by an increase in total fluid volume at 34–40 weeks due to an increase in both the extracellular and intracellular water compartments, but with a predominance of the extracellular compartment. By the 7th day of the postpartum period, there is a tendency to decrease the total fluid volume, however, interstitial and intracellular edema can be still observed. Conclusions. The results of the bioelectrical impe-dance analysis of the body water compartments show that additional methods of treatment are needed to correct the body water compartments in women with preeclampsia.

scholarly journals The Polycomb group protein MEDEA controls cell proliferation and embryonic patterning in Arabidopsis

2020 ◽  
Author(s):  
Sara Simonini ◽  
Marian Bemer ◽  
Stefano Bencivenga ◽  
Valeria Gagliardini ◽  
Nuno D. Pires ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Lineage ◽  
Embryonic Cell ◽  
The Body ◽  
Polycomb Group ◽  
Normal Embryo ◽  
Embryonic Patterning ◽  
Polycomb Group Protein ◽  
Group Protein

Establishing the body plan of a multicellular organism relies on precisely orchestrated cell divisions coupled with pattern formation. In animals, cell proliferation and embryonic patterning are regulated by Polycomb group (PcG) proteins that form various multisubunit complexes (Grossniklaus and Paro, 2014). The evolutionary conserved Polycomb Repressive Complex 2 (PRC2) trimethylates histone H3 at lysine 27 (H3K27me3) and comes in different flavors in the model plant Arabidopsis thaliana (Förderer et al., 2016; Grossniklaus and Paro, 2014). The histone methyltransferase MEDEA (MEA) is part of the FERTILIZATION INDEPENDENT SEED (FIS)-PRC2 required for seed development4. Although embryos derived from mea mutant egg cells show morphological abnormalities (Grossniklaus et al., 1998), defects in the development of the placenta-like endosperm are considered the main cause of seed abortion (Kinoshita et al., 1999; Scott et al., 1998), and a role of FIS-PRC2 in embryonic patterning was dismissed (Bouyer et al., 2011; Leroy et al., 2007). Here, we demonstrate that endosperm lacking MEA activity sustains normal embryo development and that embryos derived from mea mutant eggs abort even in presence of a wild-type endosperm because MEA is required for embryonic patterning and cell lineage determination. We show that, similar to PcG proteins in mammals, MEA regulates embryonic growth by repressing the transcription of core cell cycle components. Our work demonstrates that Arabidopsis embryogenesis is under epigenetic control of maternally expressed PcG proteins, revealing that PRC2 was independently recruited to control embryonic cell proliferation and patterning in animals and plants.

Becoming Gypsy: Tell Me What the Body Knows in Flamenco Dance

2015 ◽  
Vol 6 (1) ◽  
pp. 22-35
Author(s):  
Diane Oatley
Keyword(s):  
Knowledge Acquisition ◽  
The Body ◽  
Physical Interaction ◽  
Embodied Knowledge ◽  
Physical Processes ◽  
The Unconscious ◽  
The World ◽  
Language And Cognition ◽  
Experiences Of Women

Abstract In The Meaning of the Body, philosopher Mark Johnson makes a case for the significance of movement in terms of the body processes he holds as essential to the generation of meaning and knowledge acquisition in physical interaction with the world–equally essential as language and cognition. The article employs this theory in interpreting the experiences of women learning flamenco dance in Spain. The investigation of the perceptions of women studying flamenco dance, a dance tradition often defined as “gypsy,” indicates that exposure to flamenco dance and culture leads to revision of stereotypes regarding embodiment and difference, but respondents did not relate this revision to bodily engagement, or physical processes particular to dancing flamenco. Although Johnson’s failure to properly account for the role of the unconscious proved to be a serious shortcoming in the theory, and one which had implications for the findings, application of the theory disclosed the parameters of a discourse on the body in flamenco. The theory thus represents a radical gesture in redefining embodiment in its own right in a manner that precludes dualism with the consequent opening of a range of alternative perspectives on the articulation of embodied knowledge.

Changes in the rate of cell divisions in the course of early development of diploid and haploid loach embryos

Development ◽  
1968 ◽  
Vol 20 (2) ◽  
pp. 141-150
Author(s):  
N. N. Rott ◽  
G. A. Sheveleva
Keyword(s):  
Cell Division ◽  
Early Development ◽  
Subsequent Development ◽  
Nuclear Function ◽  
Second Stage ◽  
Cell Divisions ◽  
Genetic Activity ◽  
Synchronous Cell ◽  
Nuclear Synthesis ◽  
Two Stages

The period of development preceding gastrulation can be divided into two stages. The first is characterized by rapid synchronous cell division. True interphase, which is characterized by the fusion of karyomers and the occurrence of a nucleolus, is absent at this stage. During the second stage the rate of cell division decreases and divisions are asynchronous. The process of cell division is antagonistic to genetic activity of nuclei, as nuclear synthesis of m-RNA appears to cease during mitosis. Consequently, one can suggest that the increase of the length of interphase is necessary for the onset of morphogenetic nuclear function, which ensures gastrulation and subsequent development (Neyfakh, 1959). The present investigation was designed first to determine exactly the time of the appearance of the changes in the rate of cell division and to compare it with the time of onset of morphogenetic nuclear function.

The molecular basis for metameric pattern in the Drosophila embryo

Development ◽  
1987 ◽  
Vol 101 (1) ◽  
pp. 1-22 ◽  
Author(s):  
M. Akam
Keyword(s):  
Molecular Basis ◽  
Subsequent Development ◽  
The Body ◽  
Drosophila Embryo ◽  
Homeotic Genes ◽  
Simple Pattern ◽  
Segment Polarity ◽  
Maternal Determinants ◽  
Segment Pattern ◽  
Pair Rule

The metameric organization of the Drosophila embryo is generated in the first 5 h after fertilization. An initially rather simple pattern provides the foundation for subsequent development and diversification of the segmented part of the body. Many of the genes that control the formation of this pattern have been identified and at least twenty have been cloned. By combining the techniques of genetics, molecular biology and experimental embryology, it is becoming possible to unravel the role played by each of these genes. The repeating segment pattern is defined by the persistent expression of engrailed and of other genes of the ‘segment polarity’ class. The establishment of this pattern is directed by a transient molecular prepattern that is generated in the blastoderm by the activity of the ‘pair-rule’ genes. Maternal determinants at the poles of the egg coordinate this prepattern and define the anteroposterior sequence of pattern elements. The primary effect of these determinants is not known, but genes required for their production have been identified and the product of one of these, bicoid is known to be localized at the anterior of the egg. One early consequence of their activity is to define domains along the A-P axis within which a series of ‘cardinal’ genes are transcribed. The activity of the cardinal genes is required both to coordinate the process of segmentation and to define the early domains of homeotic gene expression. Further interactions between the homeotic genes and other classes of segmentation genes refine the initial establishment of segment identities.

Wool follicle development in the New Zealand Romney and N type sheep. II. Follicle population density during foetal development

1958 ◽  
Vol 9 (1) ◽  
pp. 138 ◽  
Author(s):  
SK Stephenson
Keyword(s):  
New Zealand ◽  
Population Density ◽  
Subsequent Development ◽  
The Body ◽  
Limiting Factor ◽  
Follicle Development ◽  
Primary Follicle ◽  
Foetal Development ◽  
Secondary Follicle ◽  
The Face

Quantitative aspects of follicle initiation and development have been studied in a series of N-type and New Zealand Romney foetuses. Density of the follicle population and ratios of secondary to primary follicles were examined on 13 positions of the body which covered the main wool-bearing areas, the face and head, and the limbs. Primary follicle development is initiated first on the head and limbs and throughout subsequent development these regions are most advanced. Primary follicle density reaches a maximum between 75 and 90 days of foetal age, after which it decreases as a result of skin growth. Secondary follicle initiation is more rapid on the wool-bearing areas of the body, and higher ratios of secondary to primary follicles are recorded from these regions. No real differences have been found between N-type and New Zealand Romney foetuses in population density of the different follicle types at any age or in the number of secondary follicles developed per primary follicle. The growth of larger primary fibres and follicles in N-type foetuses is not accompanied by, and does not result from, a lower density of primary follicles. There does not appear to be any marked relation between the decreasing density of primary follicles after 90 days of foetal age and the initiation of secondary follicle anlagen. This fact, and the absence of any differences in the number of secondary anlagen formed per primary follicle in N-types, suggest that crowding in N-types is not a limiting factor in the formation of secondary follicle anlagen.

191 RISK ASSESSMENT OF BISPHENOL A, AN ENDOCRINE DISRUPTOR, VIA PROLIFERATIVE EFFECT ON THE GROWTH OF ESTROGEN-DEPENDENT OVARIAN CANCER IN CELLULAR AND ANIMAL MODELS

2013 ◽  
Vol 25 (1) ◽  
pp. 244
Author(s):  
K.-A. Hwang ◽  
K.-C. Choi
Keyword(s):  
Cell Cycle ◽  
Ovarian Cancer ◽  
Cell Proliferation ◽  
Bisphenol A ◽  
Cancer Cells ◽  
The Body ◽  
Brdu Incorporation ◽  
Ovarian Cancer Cells ◽  
Tumour Proliferation

One of estrogens in the body, 17β-oestradiol (E2), is a pleiotropic hormone that regulates the growth and differentiation of many tissues and also acts as a mitogen that promotes the development and proliferation of hormone-responsive cancers such as breast and ovarian carcinomas. Xenoestrogens are chemical compounds that imitate oestrogen in living organisms and are classified as a type of endocrine-disrupting chemical (EDC). Bisphenol A (BPA) is a widely used industrial compound, and also known as an EDC and especially a xenoestrogen. In this study, we examined the effect of E2 or BPA on the cell growth of BG-1 ovarian cancer cells in vivo and in vitro. In the cell proliferation assay in vitro, E2 or BPA increased the growth of the BG-1 ovarian cancer cells expressing oestrogen receptors (ER). Their proliferation activity was reversed by the treatment of ICI 182 780, a well-known antagonist of ER, which demonstrates that the cell proliferation by E2 or BPA is mediated by ER and BPA certainly acts as a xenoestrogen in the BG-1 ovarian cancer cells. Clearly, E2 and BPA increased the expression of cyclin D1, a factor responsible for the G1/S cell cycle transition. These reagents also decreased the expression of p21, a potent cyclin-dependent kinase (CDK) inhibitor that arrests the cell cycle in the G1 phase. As a result, they promoted the proliferation of BG-1 cells via upregulation of the cell cycle progression. In mice xenograft models transplanted with BG-1 ovarian cancer cells, E2 or BPA administration significantly induced the tumour proliferation compared with vehicle (corn oil) treatment for 10 weeks, which was identified by the measurement of tumour volume and histological analysis on tumour tissues such as hematoxylin and eosin (H&E) staining and BrdU incorporation assay. Taken together, as an EDC having a xenoestrogenic activity, BPA was demonstrated to have a risk of tumour proliferation in oestrogen-dependent cancers such as ovarian cancer. This work was supported by a National Research Foundation of Korea (NRF) grant funded by the Ministry of Education, Science and Technology (MEST) of government of Korea (no. 2011-0015385).

Renaissance Psychologies

2017 ◽  
Author(s):  
Robert Lanier Reid
Keyword(s):  
Wave Theory ◽  
The Body ◽  
Physical Processes ◽  
The Unconscious ◽  
The Past ◽  
Immortal Soul ◽  
Rhythmic Cycles ◽  
Key Features ◽  
Immediate Experience ◽  
Plot Design

Thirteen writershave comprehensively explained theRenaissance scheme of physiology-psychology used for nosce teipsum, to ‘know oneself’, and other scholars have analysed key features likehumours, bodily spirits, passions, reason, inner wits, soul and spirit, mystic apprehension.Only poetswith epic scope, like Spenser and Shakespeare, depict human nature holistically, yet these finest poets have radically distinct psychologies.Spenser’s Christianised Platonism prioritises the soul, his art mirroringdivine Creation as dogmatically and encyclopedically conceived. He looks to the past, collating classical and medieval authorities in memory-devices like the figurative house, nobly ordered in triadic mystic numerical hierarchyto reform the ruins of time. Shakespeare’s sophisticated Aristoteleanism prioritises the body, highlighting physical processes and dynamic feelings of immediate experience, and subjecting them to intense, skeptical consciousness. He points to the future, using the witty ironies of popular stage productions to test and deconstruct prior authority, opening the unconscious to psychoanalysis. This polarity of psychologies is radical and profound, resembling the complementary theories of physics, structuring reality either (like Spenser) in the neatly-contained form of particle theory, or (like Shakespeare) in the rhythmic cycles of wave theory. How do we explain these distinct concepts, and how are they related? These poets’ contrary artistry appears in strikingly different versions of a ‘fairy queen’, of humour-based passions (notably the primal passion of self-love), of intellection (divergent modes of temptation and of moral resolution), of immortal soul and spirit, of holistic plot design, and of readiness for final judgment.

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