Study of the Molecular Architecture of Keratin Filaments by Electron Microscopy

1982 ◽  
Vol 40 ◽  
pp. 118-119
Author(s):  
U. Aebi ◽  
P. Rew ◽  
T.-T. Sun
Keyword(s):  
Electron Microscopy ◽  
Structural Organization ◽  
Cell Types ◽  
Structural Features ◽  
Molecular Architecture ◽  
The Past ◽  
Keratin Filaments ◽  
Different Types ◽  
10 Nm Filaments ◽  
Different Cell Types

Various types of intermediate-sized (10-nm) filaments have been found and described in many different cell types during the past few years. Despite the differences in the chemical composition among the different types of filaments, they all yield common structural features: they are usually up to several microns long and have a diameter of 7 to 10 nm; there is evidence that they are made of several 2 to 3.5 nm wide protofilaments which are helically wound around each other; the secondary structure of the polypeptides constituting the filaments is rich in ∞-helix. However a detailed description of their structural organization is lacking to date.

scholarly journals Pancreatic α and β cells are globally phase-locked

2020 ◽  
Author(s):  
Huixia Ren ◽  
Yanjun Li ◽  
Chengsheng Han ◽  
Yi Yu ◽  
Bowen Shi ◽  
...  
Keyword(s):  
Islet Cells ◽  
Cell Types ◽  
Phase Oscillators ◽  
Β Cells ◽  
Oscillation Modes ◽  
Different Types ◽  
Glucagon And Insulin ◽  
Different Cell Types

ABSTRACTThe Ca2+ modulated pulsatile secretions of glucagon and insulin by pancreatic α and β cells play a key role in glucose metabolism and homeostasis. However, how different types of islet cells couple and coordinate via paracrine interactions to produce various Ca2+ oscillation patterns are still elusive. By designing a microfluidic device to facilitate long-term recording of islet Ca2+ activity at single cell level and simultaneously identifying different cell types in live islet imaging, we show heterogeneous but intrinsic Ca2+ oscillation patterns of islets upon glucose stimulation. The α and β cells oscillate in antiphase and are globally phase locked to various phase delays, causing fast, slow or mixed oscillations. A mathematical model of coupled phase oscillators quantitatively agrees with experiments and reveals the essential role of paracrine regulations in tuning the oscillation modes. Our study highlights the importance of cell-cell interactions to generate stable but tunable islet oscillation patterns.

scholarly journals Assembly of multiple dystrobrevin-containing complexes in the kidney

2000 ◽  
Vol 113 (15) ◽  
pp. 2715-2724
Author(s):  
N.Y. Loh ◽  
S.E. Newey ◽  
K.E. Davies ◽  
D.J. Blake
Keyword(s):  
Skeletal Muscle ◽  
Protein Complexes ◽  
Cell Types ◽  
Epithelial Morphogenesis ◽  
Basal Region ◽  
Molecular Architecture ◽  
Renal Epithelial Cells ◽  
Specific Antibodies ◽  
Different Cell Types ◽  
Deficient Mice

Dystrophin is the key component in the assembly and maintenance of the dystrophin-associated protein complex (DPC) in skeletal muscle. In kidney, dystroglycan, an integral component of the DPC, is involved in kidney epithelial morphogenesis, suggesting that the DPC is important in linking the extracellular matrix to the internal cytoskeleton of kidney epithelia. Here, we have investigated the molecular architecture of dystrophin-like protein complexes in kidneys from normal and dystrophin-deficient mice. Using isoform-specific antibodies, we show that the different cell types that make up the kidney maintain different dystrophin-like complexes. These complexes can be broadly grouped according to their dystrobrevin content: beta-dystrobrevin containing complexes are present at the basal region of renal epithelial cells, whilst alpha-dystrobrevin-1 containing complexes are found in endothelial and smooth muscle cells. Furthermore, these complexes are maintained even in the absence of all dystrophin isoforms. Thus our data suggest that the functions and assembly of the dystrophin-like complexes in kidney differ from those in skeletal muscle and implicate a protein other than dystrophin as the primary molecule in the assembly and maintenance of kidney complexes. Our findings also provide a possible explanation for the lack of kidney pathology in Duchenne muscular dystrophy patients and mice lacking all dystrophin isoforms.

Mucopolysaccharidosis in Adults

2016 ◽  
Author(s):  
Christian J. Hendriksz ◽  
Francois Karstens
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Autosomal Recessive ◽  
Clinical Symptoms ◽  
Cell Types ◽  
Type Ii ◽  
System P ◽  
Different Types ◽  
The Central Nervous System ◽  
Different Cell Types

There are 8 different types of diseases of the mucopolysaccharides, each caused by a deficiency in one of 10 different enzymes involved in the degradation of glycosaminoglycans (GAGs). Partially degraded GAGs accumulate within the lysosomes of many different cell types and lead to clinical symptoms and excretion of large amounts of GAGs in the urine. Heritability is autosomal recessive except for MPS type II, which is X-linked. The disorders are chronic and progressive and, although the specific types all have their individual features, they share an abundance of clinical similarities. All involve the musculoskeletal, the cardiovascular, the pulmonary and the central nervous system.

The ultrastructural development of the schistosome egg granuloma in mice

Parasitology ◽  
1977 ◽  
Vol 75 (1) ◽  
pp. 119-123 ◽  
Author(s):  
Mary D. Smith
Keyword(s):  
Electron Microscopy ◽  
Schistosoma Mansoni ◽  
Cell Types ◽  
Delayed Hypersensitivity ◽  
Hypersensitivity Response ◽  
Type Reaction ◽  
Early Stages ◽  
Hepatic Granulomas ◽  
Different Cell Types

Hepatic granulomas from mice infected with Schistosoma mansoni for periods of 8 weeks to 1 year were studied by electron microscopy. The different cell types present in the granulomas suggested that whilst a delayed hypersensitivity response predominated during early stages of infection an Arthus-type reaction associated with delayed hypersensi-tivity occurred at later stages of infection.

scholarly journals Adiponectin: a pleiotropic hormone with multifaceted roles

2021 ◽  
Vol 67 (6) ◽  
pp. 98-112
Author(s):  
S. S. Shklyaev ◽  
G. A. Melnichenko ◽  
N. N. Volevodz ◽  
N. A. Falaleeva ◽  
S. A. Ivanov ◽  
...  
Keyword(s):  
Cell Types ◽  
The Body ◽  
Biologically Active ◽  
Protective Effects ◽  
Immune Functions ◽  
Ample Evidence ◽  
Endocrine Organs ◽  
Different Types ◽  
Different Cell Types ◽  
Pleiotropic Actions

Adipose tissue mostly composed of different types of fat is one of the largest endocrine organs in the body playing multiple intricate roles including but not limited to energy storage, metabolic homeostasis, generation of heat, participation in immune functions and secretion of a number of biologically active factors known as adipokines. The most abundant of them is adiponectin. This adipocite-derived hormone exerts pleiotropic actions and exhibits insulin-sensitizing, antidiabetic, anti-obesogenic, anti-inflammatory, antiatherogenic, cardio- and neuroprotective properties. Contrariwise to its protective effects against various pathological events in different cell types, adiponectin may have links to several systemic diseases and malignances. Reduction in adiponectin levels has an implication in COVID-19-associated respiratory failure, which is attributed mainly to a phenomenon called ‘adiponectin paradox’. Ample evidence about multiple functions of adiponectin in the body was obtained from animal, mostly rodent studies. Our succinct review is entirely about multifaceted roles of adiponectin and mechanisms of its action in different physiological and pathological states.

High-resolution SEM of kidney tissue using cryo-techniques

1990 ◽  
Vol 48 (3) ◽  
pp. 8-9
Author(s):  
P Walther ◽  
P Herter ◽  
J Hentschel ◽  
H Hentschel
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Room Temperature ◽  
Kidney Tissue ◽  
Cell Types ◽  
Electron Gun ◽  
Precise Localization ◽  
Transmission Electron ◽  
Different Cell Types ◽  
Scanning Electron

The kidney is a complex zonated organ with a variety of different cell types. For the study of the functional and morphological features, the precise localization in the zones is relevant, which requires the evaluation of rather large portions of tissue. Transmission electron microscopy of replicas of tissue is limited by difficulties to obtain sufficiently large specimens. In order to overcome this problem cryopreparation methods and high resolution field emission scanning electron microscopy (SEM) were used.1 mm3 cubes of perfusion fixed rabbit kidneys cryoprotected with glycerol were frozen by plunging into liquid propane. For further preparation two different methods were employed.1: Samples were fractured in liquid nitrogen with a scalpel, freeze substituted using methanol with glutaraldehyde and osmiumtetroxid, warmed to room temperature, critical point dried, and coated by electron gun evaporation with 2 nm of platinum at an angle of 45°, and 10 nm of carbon perpendicularly.

scholarly journals Chromosomal attachments set length and microtubule number in the Saccharomyces cerevisiae mitotic spindle

2014 ◽  
Vol 25 (25) ◽  
pp. 4034-4048 ◽  
Author(s):  
Natalie J. Nannas ◽  
Eileen T. O’Toole ◽  
Mark Winey ◽  
Andrew W. Murray
Keyword(s):  
Electron Microscopy ◽  
Saccharomyces Cerevisiae ◽  
Simple Model ◽  
Mitotic Spindle ◽  
Cell Types ◽  
Yeast Saccharomyces Cerevisiae ◽  
Spindle Poles ◽  
Length Regulation ◽  
Spindle Microtubules ◽  
Different Cell Types

The length of the mitotic spindle varies among different cell types. A simple model for spindle length regulation requires balancing two forces: pulling, due to micro­tubules that attach to the chromosomes at their kinetochores, and pushing, due to interactions between microtubules that emanate from opposite spindle poles. In the budding yeast Saccharomyces cerevisiae, we show that spindle length scales with kinetochore number, increasing when kinetochores are inactivated and shortening on addition of synthetic or natural kinetochores, showing that kinetochore–microtubule interactions generate an inward force to balance forces that elongate the spindle. Electron microscopy shows that manipulating kinetochore number alters the number of spindle microtubules: adding extra kinetochores increases the number of spindle microtubules, suggesting kinetochore-based regulation of microtubule number.

Fabrication of Electrochemical Sensors Based on Nanostructured Titanium Dioxide Formed through Anodic Oxidation

2015 ◽  
Vol 245 ◽  
pp. 182-189 ◽  
Author(s):  
Nikolai B. Kondrikov ◽  
Antonina S. Lapina ◽  
Ilya V. Stepanov ◽  
Galina I. Marinina ◽  
Vladimir V. Korochentsev ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Titanium Dioxide ◽  
Anodic Oxidation ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Sensors ◽  
Structural Features ◽  
X Ray ◽  
Different Types ◽  
Scanning Electron

The nanotubular titanium dioxide structures were prepared using anodic oxidation. The structural features of surface have been investigated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and energy-dispersive spectroscopy (EDS) techniques. These nanotubular titanium dioxide structures can be used as a sensor in potentiometric indication components of different types of chemical reactions.

scholarly journals Structure and assembly of CAV1 8S complexes revealed by single particle electron microscopy

2020 ◽  
Vol 6 (49) ◽  
pp. eabc6185
Author(s):  
Bing Han ◽  
Jason C. Porta ◽  
Jessica L. Hanks ◽  
Yelena Peskova ◽  
Elad Binshtein ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Membrane Protein ◽  
Single Particle ◽  
Structural Organization ◽  
Building Blocks ◽  
Structural Features ◽  
Outer Ring ◽  
Current Evidence ◽  
Caveolin 1 ◽  
Single Particle Electron Microscopy

Highly stable oligomeric complexes of the monotopic membrane protein caveolin serve as fundamental building blocks of caveolae. Current evidence suggests these complexes are disc shaped, but the details of their structural organization and how they assemble are poorly understood. Here, we address these questions using single particle electron microscopy of negatively stained recombinant 8S complexes of human caveolin 1. We show that 8S complexes are toroidal structures ~15 nm in diameter that consist of an outer ring, an inner ring, and central protruding stalk. Moreover, we map the position of the N and C termini and determine their role in complex assembly, and visualize the 8S complexes in heterologous caveolae. Our findings provide critical insights into the structural features of 8S complexes and allow us to propose a model for how these highly stable membrane-embedded complexes are generated.

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