scholarly journals A SMALL PARTICULATE COMPONENT OF THE CYTOPLASM

1955 ◽  
Vol 1 (1) ◽  
pp. 59-68 ◽  
Author(s):  
George E. Palade
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Types ◽  
High Density ◽  
Ground Substance ◽  
Degree Of Differentiation ◽  
High Degree

A particulate component of small dimensions (100 to 150 A) and high density is described in the ground substance of the cytoplasm of mammalian and avian cells. In many cell types that seem to have in common a high degree of differentiation, the new component is preferentially associated with the membrane of the endoplasmic reticulum; whereas in other cell types, characterized by rapid proliferation, it occurs more or less freely distributed in the ground substance of the cytoplasm. In the Discussion an attempt is made to integrate the observations presented in this paper with the already available cytological, histochemical, and cytochemical information.

scholarly journals The Fine Structure of Blastema Cells and Differentiating Cartilage Cells in Regenerating Limbs of Amblystoma Larvae

1958 ◽  
Vol 4 (5) ◽  
pp. 583-592 ◽  
Author(s):  
Elizabeth D. Hay
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Cell Types ◽  
Ground Substance ◽  
High Concentration ◽  
Blastema Cell ◽  
Undifferentiated Cells ◽  
Abundant Cytoplasm ◽  
Cartilage Cells ◽  
Cell Changes

Regenerating forelimbs of larval salamanders, Amblystoma punctatum, were fixed in OsO4 at various intervals after amputation and were sectioned for study with the electron microscope. The dedifferentiated cells comprising the early blastema were found to have a fine structure similar to that of other undifferentiated cells and to have lost all of the identifying morphological features of their tissues of origin. The cytoplasm of such cells is characterized by numerous free ribonucleoprotein granules and a discontinuous vesicular endoplasmic reticulum. The cells have more abundant cytoplasm and are in closer contact with each other than was previously realized. The layer of condensed ground substance investing most differentiated cell types is lacking. After a period of rapid cell division, the morphology of the blastema cell changes. Cytoplasm is now sparse and contains a high concentration of free ribonucleoprotein granules, but little endoplasmic reticulum. The differentiating cartilage cell, however, develops an extensive, highly organized endoplasmic reticulum and the Golgi apparatus also appears to become more highly differentiated and more extensive at this time. Small vesicles appear throughout the cytoplasm at the time the new cisternae originate and may contribute to their formation. These and other changes in the cytoplasmic organelles are discussed.

Organisation in the Structure of the Cytoplasmic Ground Substance

1978 ◽  
Vol 36 (3) ◽  
pp. 627-639
Author(s):  
K.R. Porter
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Complex ◽  
Random Distribution ◽  
Ground Substance ◽  
The Matrix ◽  
Cell Processes ◽  
Cytoplasmic Ground Substance

Most types of cells are known from their structure and overall form to possess a characteristic organization. In some instances this is evident in the non-random disposition of organelles and such system subunits as cisternae of the endoplasmic reticulum or the Golgi complex. In others it appears in the distribution and orientation of cytoplasmic fibrils. And in yet others the organization finds expression in the non-random distribution and orientation of microtubules, especially as found in highly anisometric cells and cell processes. The impression is unavoidable that in none of these cases is the organization achieved without the involvement of the cytoplasmic ground substance (CGS) or matrix. This impression is based on the fact that a matrix is present and that in all instances these formed structures, whether membranelimited or filamentous, are suspended in it. In some well-known instances, as in arrays of microtubules which make up axonemes and axostyles, the matrix resolves itself into bridges (and spokes) between the microtubules, bridges which are in some cases very regularly disposed and uniform in size (Mcintosh, 1973; Bloodgood and Miller, 1974; Warner and Satir, 1974).

Prevalence of the pit and antipit in the genus Glycine

1987 ◽  
Vol 45 ◽  
pp. 986-987
Author(s):  
R. W. Yaklich ◽  
E. L. Vigil ◽  
W. P. Wergin
Keyword(s):  
Amino Acids ◽  
Endoplasmic Reticulum ◽  
Glycine Max ◽  
Seed Coat ◽  
Cell Types ◽  
Abaxial Surface ◽  
Legume Seed ◽  
Initial Report ◽  
Cone Cells ◽  
Glycine Max L

The legume seed coat is the site of sucrose unloading and the metabolism of imported ureides and synthesis of amino acids for the developing embryo. The cell types directly responsible for these functions in the seed coat are not known. We recently described a convex layer of tissue on the inside surface of the soybean (Glycine max L. Merr.) seed coat that was termed “antipit” because it was in direct opposition to the concave pit on the abaxial surface of the cotyledon. Cone cells of the antipit contained numerous hypertrophied Golgi apparatus and laminated rough endoplasmic reticulum common to actively secreting cells. The initial report by Dzikowski (1936) described the morphology of the pit and antipit in G. max and found these structures in only 68 of the 169 seed accessions examined.

scholarly journals Effects of taurolithocholate, a Ca2+-mobilizing agent, on cell Ca2+ in rat hepatocytes, human platelets and neuroblastoma NG108-15 cell line

1991 ◽  
Vol 273 (1) ◽  
pp. 153-160 ◽  
Author(s):  
J F Coquil ◽  
B Berthon ◽  
N Chomiki ◽  
L Combettes ◽  
P Jourdon ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Bile Acid ◽  
Cell Line ◽  
Rat Liver ◽  
Neuronal Cell ◽  
Rat Hepatocytes ◽  
Cell Types ◽  
Liver Cells ◽  
Human Platelets ◽  
Rat Liver Cells

The monohydroxy bile acid taurolithocholate permeabilizes the endoplasmic reticulum to Ca2+ in rat liver cells. To assess whether this action on the endoplasmic reticulum was restricted to this tissue, the effects of bile acid were investigated in two cell types quite unrelated to rat hepatocyte, namely human platelets and neuronal NG108-15 cell line. The results showed that taurolithocholate (3-100 microM) had no effect on free cytosolic [Ca2+] in human platelets and NG108-15 cells. whereas it increased it from 180 to 520 nM in rat hepatocytes. In contrast, in cells permeabilized by saponin, taurolithocholate initiated a profound release of the stored Ca2+ from the internal Ca2+ pools in the three cell types. The bile acid released 90% of the Ca2+ pools, with rate constants of about 5 min-1 and half-maximal effects at 15-30 microM. The results also showed that, in contrast with liver cells, which displayed an influx of [14C]taurolithocholate of 2 nmol/min per mg, human platelets and the neuronal cell line appeared to be resistant to [14C]taurolithocholate uptake. The influx measured in these latter cells was about 100-fold lower than in rat liver cells. Taken together, these data suggest that human platelets and NG108-15 cells do not possess the transport system for concentrating monohydroxy bile acids into cells. However, they show that human platelets and neuronal NG108-15 possess, in common with liver cells, the intracellular system responsible for taurolithocholate-mediated Ca2+ release from internal stores.

scholarly journals Biosynthesis of the insulin receptor in rat adipose cells. Intracellular processing of the Mr-190 000 pro-receptor

1985 ◽  
Vol 232 (1) ◽  
pp. 71-78 ◽  
Author(s):  
J A Hedo ◽  
I A Simpson
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Insulin Receptor ◽  
Golgi Complex ◽  
Microsomal Fraction ◽  
Primary Cultures ◽  
Sodium Dodecyl ◽  
High Density ◽  
Low Density ◽  
Adipose Cells

We investigated the biosynthesis of the insulin receptor in primary cultures of isolated rat adipose cells. Cells were pulse-chase-labelled with [3H]mannose, and at intervals samples were homogenized. Three subcellular membrane fractions were prepared by differential centrifugation: high-density microsomal (endoplasmic-reticulum-enriched), low-density microsomal (Golgi-enriched), and plasma membranes. After detergent solubilization, the insulin receptors were immunoprecipitated with anti-receptor antibodies and analysed by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and autoradiography. After a 30 min pulse-label [3H]mannose first appeared in a band of Mr 190 000. More than 80% of the Mr-190 000 component was recovered in the microsomal fractions. Its intensity reached a maximum at 1 h in the high-density microsomal fraction and at 2 h in the low-density microsomal fraction, and thereafter declined rapidly (t 1/2 approx. 3 h) in both fractions. In the plasma-membrane fraction, the radioactivity in the major receptor subunits, of Mr 135 000 (alpha) and 95 000 (beta), rose steadily during the chase and reached a maximum at 6 h. The Mr-190 000 precursor could also be detected in the high-density microsomal fraction by affinity cross-linking to 125I-insulin. In the presence of monensin, a cationic ionophore that interferes with intracellular transport within the Golgi complex, the processing of the Mr-190 000 precursor into the alpha and beta subunits was completely inhibited. Our results suggest that the Mr-190 000 pro-receptor originates in the endoplasmic reticulum and is subsequently transferred to the Golgi complex. Maturation of the pro-receptor does not seem to be necessary for the expression of the insulin-binding site. Processing of the precursor into the mature receptor subunits appears to occur during the transfer of the pro-receptor from the Golgi complex to the plasma membrane.

scholarly journals High-Density Lipoprotein Prevents Endoplasmic Reticulum Stress-Induced Downregulation of Liver LOX-1 Expression

PLoS ONE ◽  
2015 ◽  
Vol 10 (4) ◽  
pp. e0124285 ◽  
Author(s):  
Dan Hong ◽  
Ling-Fang Li ◽  
Hai-Chao Gao ◽  
Xiang Wang ◽  
Chuan-Chang Li ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
High Density Lipoprotein ◽  
Density Lipoprotein ◽  
High Density

scholarly journals RhoA localization with caveolin-1 regulates vascular contractions to serotonin

2012 ◽  
Vol 303 (9) ◽  
pp. R959-R967 ◽  
Author(s):  
Daniel W. Nuno ◽  
Sarah K. England ◽  
Kathryn G. Lamping
Keyword(s):  
Lipid Rafts ◽  
Rho Kinase ◽  
Initial Response ◽  
Cell Types ◽  
Smooth Muscle Contraction ◽  
High Density ◽  
Low Density ◽  
Density Fractions ◽  
Caveolin 1 ◽  
Multiple Cell

Vascular smooth muscle contraction occurs following an initial response to an increase in intracellular calcium concentration and a sustained response following increases in the sensitivity of contractile proteins to calcium (calcium sensitization). This latter process is regulated by the rhoA/rho kinase pathway and activated by serotonin. In multiple cell types, signaling molecules compartmentalize within caveolae to regulate their activation. We hypothesized that serotonin differentially compartmentalizes rhoA within caveolar versus noncaveolar lipid rafts to regulate sustained vascular contractions. To test this hypothesis, we measured aortic contractions in response to serotonin in wild-type (WT) and cav-1-deficient mice (cav-1 KO). RhoA-dependent contractions in response to serotonin were markedly augmented in arteries from cav-1 KO mice despite a modest reduction in rhoA expression compared with WT. We found that under basal conditions, rhoA in WT arteries was primarily localized within high-density sucrose gradient fractions but temporally shifted to low-density fractions in response to serotonin. In contrast, rhoA in cav-1 KO arteries was primarily in low-density fractions and shifted to high-density fractions in a similar timeframe as that seen in WT mice. We conclude that localization of rhoA to caveolar versus noncaveolar lipid rafts differentially regulates its activation and contractions to rhoA-dependent agonists with greater activation associated with its localization to noncaveolar rafts. Disruption of rhoA localization within caveolae may contribute to increased activation and enhanced vascular contractions in cardiovascular disease.

Differentiation of Self in the Therapist's Family of Origin

1980 ◽  
Vol 61 (7) ◽  
pp. 394-399 ◽  
Author(s):  
Philip Rich
Keyword(s):  
Family Therapy ◽  
Family Systems ◽  
Family Of Origin ◽  
Therapeutic Process ◽  
Differentiation Of Self ◽  
Family Therapists ◽  
Essential Nature ◽  
Degree Of Differentiation ◽  
High Degree

The essential nature of family therapy, the role of the therapist in the therapeutic process, and the need for family therapists to possess a high degree of differentiation of self are examined. As a prerequisite to conducting successful family systems therapy, therapists must examine their own family of origin.

scholarly journals Tools of Interregional Cooperation in the Public Administration System

REGIONOLOGY ◽  
2021 ◽  
Vol 29 (2) ◽  
pp. 250-282
Author(s):  
Vladimir V. Klimanov ◽  
Sofia M. Kazakova ◽  
Vita A. Yagovkina
Keyword(s):  
Russian Federation ◽  
Regional Cooperation ◽  
Public Procurement ◽  
Financial Assessment ◽  
Scientific Potential ◽  
Interregional Cooperation ◽  
The Russian Federation ◽  
Degree Of Differentiation ◽  
Regional Authorities ◽  
High Degree

Introduction. The development of modern Russia is characterized by a high degree of differentiation in the level of socio-economic development of the constituent entities of the Russian Federation. Interregional cooperation is one of the tools to overcome this differentiation. Although new forms of such cooperation have been emerging, its potential remains underestimated. The purpose of the study is to analyze the existing and prospective forms of cooperation between the regions of Russia. Materials and Methods. The study based on a structural and substantive analysis of regulatory legal acts of the federal and regional levels, as well as on strategic planning documents, various forms of budget reporting, bilateral and multilateral agreements between the constituent entities of the Russian Federation aimed at identifying various areas, tools and mechanisms for ensuring interregional cooperation. Results. The authors have considered the tools of interregional cooperation that involve direct financial participation of regional authorities or economic entities. The role and prospects of horizontal subsidies and budget loans provided by one region to another have been identified, their legal and regulatory justification has been given; a financial assessment has been made, and the identified practices have been analyzed. In terms of the implementation of public procurement from suppliers based in other regions, the authors have estimated the degree of how closed or open the constituent entities of the Russian Federation are. Discussion and Conclusion. The authors have confirmed the idea that interregional cooperation in Russia is still underdeveloped and lacks legislative and scientific-methodological justification. The authors also assess the prospects for further development of interregional cooperation in Russia and suggest a number of measures to promote it. The results of the study can be used in the interests of the authorities to improve the system of regulation of various mechanisms of regional cooperation, as well as to develop the scientific potential in this area.

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