scholarly journals Developing Essential Rigid-Flexible Outer Sheath to Enable Novel Multi-piercing Surgery

2012 ◽  
pp. 26-33 ◽  
Author(s):  
Siyang Zuo ◽  
Takeshi Ohdaira ◽  
Kenta Kuwana ◽  
Yoshihiro Nagao ◽  
Satoshi Ieiri ◽  
...  
Keyword(s):  
Outer Sheath

scholarly journals THE ELECTRON MICROSCOPY OF THE HUMAN HAIR FOLLICLE

1957 ◽  
Vol 3 (2) ◽  
pp. 223-230 ◽  
Author(s):  
M. S. C. Birbeck ◽  
E. H. Mercer
Keyword(s):  
Hair Follicle ◽  
Cross Sections ◽  
Plasma Membranes ◽  
Membrane Complex ◽  
Outer Sheath ◽  
Root Sheath ◽  
Inner Root Sheath ◽  
Cell Layers ◽  
Adhesive Contacts ◽  
Similar Complex

1. The three cylinders of cells, each one cell thick, which together constitute the inner root sheath, arise from the peripheral portions of the undifferentiated matrix. These cells, like the hair cuticle, are stabilised by the spread of adhesive contacts between their plasma membranes which occurs in the mid-bulb and upper bulb of the hair follicle. 2. The characteristic intracellular product of all three cell layers is trichohyaline. This substance is formed in the first place as amorphous droplets which subsequently transform into a birefringent form. 3. This transformation, involving the formation of a birefringent product from an amorphous precursor, is in contrast to the formation in the cortex of keratin which originates in a fibrous form. 4. Trichohyaline appears first and transforms first in the cells of Henle which are nearest the outer sheath and the dermal supply vessels. This transformation occurs at the level of the neck of the follicle. Synthesis and transformation in the cells of Huxley and the sheath cuticle lag behind the similar events in the cells of Henle. The transformation does not begin until the lower prekeratinous zone in the Huxley and cuticle cells. 5. The amorpous-fibrous transformation occurs rapidly cell by cell and involves the conversion of all the trichohyaline droplets. In longitudinal sections the birefringent modification can be seen extending from the droplets in both directions parallel to the axis of the hair. In cross-sections the images of the transformed material are difficult to interpret. They may be seen as sections of corrugated sheets (∼100 A thick) or condensed fibrils ∼100 A in width. 6. At the same time that the trichohyaline transforms, the spacing between the cell membranes increases and a dark deposit appears centrally between them. This membrane complex, and the similar complex of the hair cuticle cells described in Part 2, may be specialised formations whose purpose is to hold the hardened cells together.

The Structure of Trichocysts in Paramecium Caudatum

1972 ◽  
Vol 11 (3) ◽  
pp. 899-929
Author(s):  
L. H. BANNISTER
Keyword(s):  
Amorphous Matrix ◽  
Boundary Surface ◽  
The Body ◽  
Single Type ◽  
Apical Region ◽  
Paramecium Caudatum ◽  
Lower Phase ◽  
Microscopic Appearance ◽  
Outer Sheath ◽  
Crystalline Matrix

The structure of undischarged and discharged trichocysts has been examined in Paramecium caudatum, and their light-microscopic appearance compared with their fine-structural organization. In living specimens undischarged trichocysts appear to be of a single type with a unimodal variation in length about a mean of 3.7 µm. When fixed for electron microscopy or compressed beneath a coverslip many of the trichocysts expand within the cell, giving rise to a variety of different forms of lower phase density. Ultrastructurally the undischarged trichocyst consists of at least 10 different components: these include a mesh-like sheath surrounding the body of the organelle; an inner and an outer sheath enclosing the tip, the inner sheath being made up of 4 spiralling envelopes with a square net substructure, and the outer sheath being formed of a dense amorphous matrix containing longitudinal microtubules and scattered fine filaments; a boundary surface to the outer sheath; a membranous trichocyst sac the apical region of which is surrounded by a cylinder of microtubules joined to each other with dense material; and lastly, the crystalline matrix of the trichocyst body and tip. This crystalline appearance is apparently related to the presence of a loosely interwoven complex of fine filaments which form a highly regular pattern of unit structures repeating at 16-nm intervals. In extended trichocysts the 60-nm banding pattern of the body is also composed of fine filaments arranged in a different, elongated manner in 2 distinct and alternating patterns which are taken to be 2 views of the same structure. Measurements indicate that when trichocysts extend they elongate by a factor of from 6 to 8. It is proposed that the crystalline pattern of the unextended trichocyst body transforms into the extended form by a simple rearrangement of the constituent filaments accompanied by their elongation. Possible models of the undischarged and discharged states of organization are suggested.

scholarly journals The major outer sheath protein forms distinct conformers and multimeric complexes in the outer membrane and periplasm of Treponema denticola

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Robbins Puthenveetil ◽  
Sanjiv Kumar ◽  
Melissa J. Caimano ◽  
Abhishek Dey ◽  
Arvind Anand ◽  
...  
Keyword(s):  
Outer Membrane ◽  
Treponema Denticola ◽  
Outer Sheath

Structural Behavior of Umbilicals: Part II—Model-Experimental Comparisons

2010 ◽  
Author(s):  
Celso Pupo Pesce ◽  
Andre´ Lui´s Condino Fujarra ◽  
Marcos Rabelo ◽  
Rafael Loureiro Tanaka ◽  
Clo´vis de Arruda Martins ◽  
...  
Keyword(s):  
External Surface ◽  
Bending Moment ◽  
Steel Tube ◽  
Strain Gages ◽  
Pressure Loading ◽  
Outer Sheath ◽  
Tension Tests ◽  
Variable Tension ◽  
Load Conditions ◽  
Experimental Comparisons

A set of tests was performed in a non-armored Steel Tube Umbilical (STU), including pure pressure loading, constant and variable tension loads and combinations of constant and cyclic bending moment and tension. Tests were made for pressurized and non pressurized conditions. Strains were measured with strain gages attached to the external surface of selected tubes. Instrumentation was performed in four windows that were opened on the umbilical outer sheath to provide access to the tubes. Besides the strains, tension, internal pressure and imposed angle were measured. Comparisons with results obtained using the model presented in Part I, [1], are presented for different load conditions.

Sheaths of the Motor Axons of the Crab Carcinus

1964 ◽  
Vol s3-105 (70) ◽  
pp. 175-181
Author(s):  
G. A. HORRIDGE ◽  
R. A. CHAPMAN
Keyword(s):  
Cell Membrane ◽  
Glial Cell ◽  
Cross Section ◽  
Glial Cells ◽  
Fibrous Material ◽  
Motor Axons ◽  
Cell Cytoplasm ◽  
Fibrous Sheath ◽  
Outer Sheath ◽  
Sheath Structure

In crab leg nerves, the largest axons, which are the motor axons usually isolated for physiological experiments, have a sheath structure which is different from that in medium sized and smaller axons of the same nerve or of any other described nerves. Axons with a diameter over 20 µ have (a) an outer sheath, about 5µ thick, of wellspaced layers of alternating glial cell cytoplasm and extracellular fibrous material, formed from fewer cells than there are layers, and (b) an inner sheath of elongated cells which creep along the axon longitudinally and interdigitate where they meet, as seen 2 or 3 times round the outside of the membranes of axons in cross-section. Therefore, possible channels between inner glial cells are elongated and few. On these structural grounds, together with physiological evidence, they seem unlikely to be preferred pathways of diffusion of ions in crab axons. Smaller axons have simple sheaths; some occur in groups within a fibrous sheath; the thinnest axons frequently occur in bundles and have no glial cell membrane in contact with them.

Note on Losses in Cable Sheaths

1928 ◽  
Vol 24 (1) ◽  
pp. 65-73 ◽  
Author(s):  
F. W. Carter
Keyword(s):  
Cross Section ◽  
Eddy Current ◽  
Distribution Systems ◽  
Power Cables ◽  
Circulating Current ◽  
Outer Sheath ◽  
The Cross ◽  
Current Flows ◽  
Made In

In a recent communication to the Society, the author referred to cable-sheath losses, and gave formulae for computing them in certain cases. These appertained to power cables in which were comprised a group of conductors, arranged symmetrically and encased in a single conducting sheath. In some distribution systems, however, the conductors for the several phases are encased in separate lead sheaths, which are either laid in proximity as separate cables, or grouped and comprehended in an outer sheath. The analysis previously given does not include such cases directly. Moreover, it is common practice either to lay the elementary cables with sheaths in contact, or to bond the sheaths together at the ends of suitable sections, in order to prevent differences of potential between them; and, when this is done, a circulating current flows in the circuit of the sheaths and bonds, sufficient to maintain equality of potential between the several sheaths. This current, to which reference was made in the former paper, is additional to the eddy current discussed therein, the integral of which over the cross section of the sheath is zero. It is for convenience here referred to as the “circulating current,” to distinguish it from the “eddy current,” although there is no such distinction between them as the names imply.

Fine structure of sensilla on the ovipositor of the tephritid fly Urophora affinis

1986 ◽  
Vol 64 (4) ◽  
pp. 973-984 ◽  
Author(s):  
R. Y. Zacharuk ◽  
R. M. K. W. Lee ◽  
D. E. Berube
Keyword(s):  
Fine Structure ◽  
Epidermal Cell ◽  
Fruit Flies ◽  
Sheath Cell ◽  
Outer Sheath ◽  
Dendritic Segment ◽  
Tubular Body ◽  
Tubular Bodies ◽  
Sheath Cells

There are four types of sensilla on the ovipositor blade of Urophora affinis Frauenfeld, one more than was observed on three other species of fruit flies studied by other authors. Three of the types, uniporous gustatory pegs, campaniform organs, and tactile short hairs are common to the four species and generally are in similar positions on the blade. The fourth, uniporous gustatory plates, were noted in U. affinis only. The chemosensilla are innervated by three chemosensory dendrites that terminate below the pore and a mechanosensory dendrite with a tubular body that is attached to a basal cuticular apodeme of the covering cuticle. The dendritic tubular bodies of the campaniform organs and tactile hairs terminate parallel to the surface in a right-angular bend, where they are attached to basal apodemes of the covering cuticle. The chemosensilla and tactile hairs have individual outer and inner sheath cells, but the campaniform organs have individual inner sheath cells only. The part of the ciliary dendritic segment that is encased by the dendritic sheath passes through an epidermal cell, often with several sensilla sharing the same epidermal cell in place of an outer sheath cell. The role of these sensilla during oviposition is discussed.

scholarly journals Induction of De Novo Subcortical Actin Filament Assembly by Treponema denticola Major Outer Sheath Protein

2004 ◽  
Vol 72 (6) ◽  
pp. 3650-3654 ◽  
Author(s):  
Mohsen Amin ◽  
Andy C. S. Ho ◽  
Jenny Y. Lin ◽  
Andre Paes Batista da Silva ◽  
Michael Glogauer ◽  
...  
Keyword(s):  
Actin Filament ◽  
De Novo ◽  
Cell Types ◽  
Treponema Denticola ◽  
Actin Reorganization ◽  
Filament Assembly ◽  
Outer Sheath

ABSTRACT Treponema denticola and its major outer sheath protein (Msp) induce actin reorganization in fibroblasts. We adapted a barbed-end labeling/imaging assay to monitor Msp-induced subcortical actin filament assembly in neutrophils and fibroblasts. Msp, at an actin-reorganizing concentration, inhibited migration of these dissimilar cell types, whose cytoskeletal functions in locomotion and phagocytosis are crucial for immunity and healing of peripheral infections.

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