scholarly journals Expression of an epidermal keratin protein in liver of transgenic mice causes structural and functional abnormalities.

1995 ◽  
Vol 128 (1) ◽  
pp. 157-169 ◽  
Author(s):  
K M Albers ◽  
F E Davis ◽  
T N Perrone ◽  
E Y Lee ◽  
Y Liu ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Cell Structure ◽  
Structure And Function ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
Inflammatory Infiltration ◽  
Intermediate Filament Proteins ◽  
And Function

To examine the role of keratin intermediate filament proteins in cell structure and function, transgenic mice were isolated that express a modified form of the human K14 keratin protein in liver hepatocytes. A modified K14 cDNA (K14.P) sequence was linked downstream of the mouse transthyretin (TTR) gene promoter and enhancer elements to achieve targeted expression in hepatocytes. Hepatocytes expressing high levels of the transgene were found to have abnormal keratin filament networks as detected by indirect immunofluorescence using an antibody specific for the transgene product. Light and electron microscopic level histological analysis of isolated liver tissue showed in many cases degenerative changes that included inflammatory infiltration, ballooning degeneration, an increase in fat containing vacuoles, and glycogen accumulation. These changes were most evident in older mice over four months of age. No indication of typical Mallory body structures were identified at either the light or electron microscopic level. To evaluate secretory function in transgenic livers, bile acid secretion rates were measured in isolated perfused liver and found to be approximately twofold lower than aged-matched controls. These findings indicate that expression of an abnormal keratin in liver epithelial cells in the in vivo setting can alter the structure and function of a tissue and suggest a role of the keratin network in cellular secretion.

The Role of the Islet Niche on Beta Cell Structure and Function

2020 ◽  
Vol 432 (5) ◽  
pp. 1407-1418 ◽  
Author(s):  
Eckhard Lammert ◽  
Peter Thorn
Keyword(s):  
Beta Cell ◽  
Cell Structure ◽  
Structure And Function ◽  
And Function

From protoplasmic theory to cellular systems biology: a 150-year reflection

2010 ◽  
Vol 298 (6) ◽  
pp. C1280-C1290 ◽  
Author(s):  
G. Rickey Welch ◽  
James S. Clegg
Keyword(s):  
Systems Biology ◽  
Cell Biology ◽  
Cell Structure ◽  
Structure And Function ◽  
Cellular Systems ◽  
Controversial Issues ◽  
Cell Theory ◽  
History Of ◽  
And Function

Present-day cellular systems biology is producing data on an unprecedented scale. This field has generated a renewed interest in the holistic, “system” character of cell structure-and-function. Underlying the data deluge, however, there is a clear and present need for a historical foundation. The origin of the “system” view of the cell dates to the birth of the protoplasm concept. The 150-year history of the role of “protoplasm” in cell biology is traced. It is found that the “protoplasmic theory,” not the “cell theory,” was the key 19th-century construct that drove the study of the structure-and-function of living cells and set the course for the development of modern cell biology. The evolution of the “protoplasm” picture into the 20th century is examined by looking at controversial issues along the way and culminating in the current views on the role of cytological organization in cellular activities. The relevance of the “protoplasmic theory” to 21st-century cellular systems biology is considered.

Microtubule-dependent subcellular organisation of pluripotent cells

Development ◽  
2021 ◽  
Vol 148 (20) ◽  
Author(s):  
Azelle Hawdon ◽  
Asma Aberkane ◽  
Jennifer Zenker
Keyword(s):  
Pluripotent Stem Cells ◽  
Cell Structure ◽  
Structure And Function ◽  
Pluripotent Cells ◽  
Differentiated Cells ◽  
Intracellular Movement ◽  
And Function

ABSTRACT With the advancement of cutting-edge live imaging technologies, microtubule remodelling has evolved as an integral regulator for the establishment of distinct differentiated cells. However, despite their fundamental role in cell structure and function, microtubules have received less attention when unravelling the regulatory circuitry of pluripotency. Here, we summarise the role of microtubule organisation and microtubule-dependent events required for the formation of pluripotent cells in vivo by deciphering the process of early embryogenesis: from fertilisation to blastocyst. Furthermore, we highlight current advances in elucidating the significance of specific microtubule arrays in in vitro culture systems of pluripotent stem cells and how the microtubule cytoskeleton serves as a highway for the precise intracellular movement of organelles. This Review provides an informed understanding of the intrinsic role of subcellular architecture of pluripotent cells and accentuates their regenerative potential in combination with innovative light-inducible microtubule techniques.

A simplified method of emulsion coating and development for quantitative electron microscopic radioautography

1978 ◽  
Vol 36 (2) ◽  
pp. 64-65
Author(s):  
K. Yoshida ◽  
F. Murata ◽  
S. Ohno ◽  
T. Nagata
Keyword(s):  
Mass Production ◽  
Identical Condition ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
Simplified Method ◽  
Complicated Process ◽  
Critical Problems ◽  
Electron Microscopic Radioautography ◽  
Quantitative Radioautography

IntroductionSeveral methods of mounting emulsion for radioautography at the electron microscopic level have been reported. From the viewpoint of quantitative radioautography, however, there are many critical problems in the procedure to produce radioautographs. For example, it is necessary to apply and develop emulsions in several experimental groups under an identical condition. Moreover, it is necessary to treat a lot of grids at the same time in the dark room for statistical analysis. Since the complicated process and technical difficulties in these procedures are inadequate to conduct a quantitative analysis of many radioautographs at once, many factors may bring about unexpected results. In order to improve these complicated procedures, a simplified dropping method for mass production of radioautographs under an identical condition was previously reported. However, this procedure was not completely satisfactory from the viewpoint of emulsion homogeneity. This paper reports another improved procedure employing wire loops.

Scanning electron microscopic study of collagen fibrillogenesis and extracellular compartmentalization in the chick embryo tendon

1986 ◽  
Vol 44 ◽  
pp. 208-209
Author(s):  
Grace C.H. Yang
Keyword(s):  
Chick Embryo ◽  
Extracellular Space ◽  
Fibroblast Cell ◽  
Collagen Fibrils ◽  
Electron Microscopic ◽  
Voltage Electron ◽  
Scanning Electron Microscopic Study ◽  
Microscopic Studies ◽  
And Function

The size and organization of collagen fibrils in the extracellular matrix is an important determinant of tissue structure and function. The synthesis and deposition of collagen involves multiple steps which begin within the cell and continue in the extracellular space. High-voltage electron microscopic studies of the chick embryo cornea and tendon suggested that the extracellular space is compartmentalized by the fibroblasts for the regulation of collagen fibril, bundle, and tissue specific macroaggregate formation. The purpose of this study is to gather direct evidence regarding the association of the fibroblast cell surface with newly formed collagen fibrils, and to define the role of the fibroblast in the control and the precise positioning of collagen fibrils, bundles, and macroaggregates during chick tendon development.

X-Ray Microanalysis of Nickel and Cobalt Intensified Peroxidase- Antiperoxidase For Verification of Reaction Sites

1985 ◽  
Vol 43 ◽  
pp. 468-469
Author(s):  
A. Angel ◽  
K. Miller ◽  
V. Seybold ◽  
R. Kriebel
Keyword(s):  
Reaction Mechanisms ◽  
Visual Discrimination ◽  
Osmium Tetroxide ◽  
Ultrastructural Level ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
X Ray ◽  
Insoluble Polymer ◽  
Cytochemical Reaction

Localization of specific substances at the ultrastructural level is dependent on the introduction of chemicals which will complex and impart an electron density at specific reaction sites. Peroxidase-antiperoxidase(PAP) methods have been successfully applied at the electron microscopic level. The PAP complex is localized by addition of its substrate, hydrogen peroxide and an electron donor, usually diaminobenzidine(DAB). On oxidation, DAB forms an insoluble polymer which is able to chelate with osmium tetroxide becoming electron dense. Since verification of reactivity is visual, discrimination of reaction product from osmiophillic structures may be difficult. Recently, x-ray microanalysis has been applied to examine cytochemical reaction precipitates, their distribution in tissues, and to study cytochemical reaction mechanisms. For example, immunoreactive sites labelled with gold have been ascertained by means of x-ray microanalysis.

Pengembangan Instrumen Penilaian Kinerja pada Praktikum Struktur dan Fungsi Sel Di SMA Negeri 1 Kota Jambi

2016 ◽  
Vol 5 (2) ◽  
Author(s):  
Nugroho Budhiwaluyo ◽  
Rayandra Asyhar ◽  
Bambang Hariyadi
Keyword(s):  
Performance Assessment ◽  
Student Performance ◽  
Cell Structure ◽  
Structure And Function ◽  
Assessment Instrument ◽  
Product Performance ◽  
Development Model ◽  
Test Results ◽  
Validity And Reliability ◽  
And Function

  This research aims to produce a final product in the form of a performance-assessment instrument on Cell Structure and Function experiment. The development model is ADDIE. Based on expert's judgment, the instrument was valid and can be tested in the field. Field-test results shown that the product performs high validity and reliability value on measuring student performance on Cell Structure and Function experiment. Therefore, it is concluded that this performance-assessment instrument theoretically and practically has a good quality for measuring student performance in both process and product performance on Cell Structure and Function experiment. Keywords: Development, Performance-Assessment Instrument, Cell Structure and Function Experiment 

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