Extracellular Connective Tissue Fibrils: A Single Line of Descent

1968 ◽  
Vol 26 ◽  
pp. 52-53
Author(s):  
F. N. Low
Keyword(s):  
Connective Tissue ◽  
Close Association ◽  
Collagen Fibrils ◽  
Elastic Fibers ◽  
Chick Embryos ◽  
Basal Surface ◽  
The Third ◽  
Tissue Space ◽  
Dorsal Ectoderm ◽  
Boundary Membrane

The fine structure of developing extracellular connective tissue fibrils, is demonstrable in normal chick embryos. Before incubation begins primary fibrils are present in the intermittent boundary membrane (basement membrane, basal lamina) of the basal surface of the epiblast. These give rise to microfibrils which first become free in the tissue space at about 24 hours incubation (Fig. 1). The first noticeable locus of microfibrillar concentration appears between the head process (early notochord) and the dorsal ectoderm. By 40 to 45 hours a heavy tangle of microfibrils occupies the acellular area surrounding the notochord and remains conspicuous during the third day (Fig. 2). At 60 to 72 hours microfibrils begin to appear in close association with free mesenchymal cells (Fig. 3). Periodicity slowly develops in the larger microfibrils and the resultant unit collagen fibrils will aggregate to form the reticular and collagen fibers of light microscopy. During the second and third weeks of incubation microfibrils and unit collagen fibrils contribute to the formation of elastic fibers.

Developing Elastic Fibers in the Chick Embryo

1968 ◽  
Vol 26 ◽  
pp. 58-59
Author(s):  
C. R. Basom
Keyword(s):  
Electron Microscopy ◽  
Elastic Fiber ◽  
Fiber Formation ◽  
Collagen Fibrils ◽  
Ground Substance ◽  
Elastic Fibers ◽  
The Third ◽  
Immersion Medium ◽  
Individual Unit ◽  
Homogeneous Matrix

The tunica media of the developing chick aorta was examined for elastic fiber formation. Embryos of three to eighteen days incubation age were prepared for electron microscopy by Karnovsky's fixation. Small embryos were fixed by “in toto” immersion: medium sized embryos were previously transected. The aortae of larger embryos were removed prior to fixation. Epon 812 was used for embedment.Irregular masses of amorphous ground substance appeared in the interstitial space of the aortae in three to five day embryos. These masses were located where elastic fibers would later form (Fig. 1). Later loose tangles of microfibrils appeared within the same masses (Fig. 2). In still older embryos, individual unit collagen fibrils appeared within this loose network. At one week's incubation, small elastic fibers could be identified by their homogeneous matrix. These arose within the conglomerate masses described above. At the beginning of the third week compact bundles of colinear unit collagen fibrils appeared (Fig. 3). These fibrils swelled, gradually lost their periodicity and became very lucid (Fig. 4).

Banded Structures in the Connective Tissue of Meningioma

1976 ◽  
Vol 34 ◽  
pp. 234-235
Author(s):  
C. N. Sun ◽  
H. J. White
Keyword(s):  
Connective Tissue ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Collagen Fibrils ◽  
Lead Citrate ◽  
Connective Tissues ◽  
Native Collagen ◽  
Routine Procedures

Previously, we have reported on extracellular cross-striated banded structures in human connective tissues of a variety of organs (1). Since then, more material has been examined and other techniques applied. Recently, we studied a fibrocytic meningioma of the falx. After the specimen was fixed in 4% buffered glutaraldehyde and post-fixed in 1% buffered osmium tetroxide, other routine procedures were followed for embedding in Epon 812. Sections were stained with uranyl acetate and lead citrate. There were numerous cross striated banded structures in aggregated bundle forms found in the connecfive tissue of the tumor. The banded material has a periodicity of about 450 Å and where it assumes a filamentous arrangement, appears to be about 800 Å in diameter. In comparison with the vicinal native collagen fibrils, the banded material Is sometimes about twice the diameter of native collagen.

scholarly journals AB0713 PERIODONTAL DISEASES AND ITS ASSOCIATION WITH ANKYLOSING SPONDYLITIS/SPA: A SYSTEMATIC REVIEW

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1652.1-1652
Author(s):  
A. Pandey ◽  
V. Ravindran ◽  
M. Pandey ◽  
R. Rajak ◽  
V. Pandey
Keyword(s):  
Systematic Review ◽  
Ankylosing Spondylitis ◽  
Connective Tissue ◽  
Inflammatory Response ◽  
Periodontal Disease ◽  
Close Association ◽  
Case Control ◽  
Clinical Attachment Loss ◽  
Tnf Α ◽  
Host Inflammatory Response

Background:A close association between periodontal disease and Ankylosing spondylitis (AS) has long been specualted. Both diseases are characterized by dysregulation of the host inflammatory response, leading to further destruction of soft and hard connective tissue with there being evidence of increased levels of TNF-α and various interleukins in both patients of AS and periodontitis.Objectives:The aim of this systematic review was to appraise the available literature exploring the relationship between AS and periodontal disease.Methods:We searched Medline & Embase databases (from their inception till October 2019) using appropriate combinations of following search items with limits ‘(English, Human)’; Ankylosing spondylitis, spondyloarthritis, spondyloarthropathies, spondyloarthritides, spinal disease, musculoskeletal disease, Rheumatic disease AND periodontitis, periodontal disease, periodontoses, parodontoses, chronic periodontitis, gum disease, gingivitis, oral health, dental health, plaque index, bleeding on probing, probing pocket depth, clinical attachment loss. This search was supplemented by the manual search of bibliographies of articles selected and conferences proceedings of EULAR. Only be reviews, observational study of cross-sectional, cohort or case control type on adult patients with AS were selected. Data was extracted from a predesigned proforma. A close association between periodontal disease and Ankylosing spondylitis (AS) has long been specualted. Both diseases are characterized by dysregulation of the host inflammatory response, leading to further destruction of soft and hard connective tissue with there being evidence of increased levels of TNF-α and various interleukins in both patients of AS and periodontitis.Results:A total number of 984 articles were identified and 12 were selcted for detailed appraisal (Figure 1, PRISMA flow chart). They were all case control studies. The prevalence of periodontitis ranged from 38% to 88% in patients with AS whereas in the control group from 26% to 71 % in controls. Out of 12 studies, two showed significant changes in Plaque Index (PI), two studies showed altered Pocket Probing Depth (PPD), three showed significant increased in Clinical Attachment Loss (CAL) and increased Bleeding On Probing (BOP) was seen in 2 studies. In 7 studies, periodontitis was seen in a significant number of patients with AS (P<0.05). All studies reported that the prevalence of periodontal disease in AS patients was higher as compared to non-AS patients.Conclusion:Our systematic review found an association between AS and periodontal disease. Patients with AS show higher prevalence of periodontitis and a poor oral hygiene as compared to healthy controls. At practice level, this systematic review underscores the need for a collaboration between dentists and rheumatologist.Disclosure of Interests:None declared

scholarly journals EXTIRPATION OF THE THYMUS IN THE GUINEA PIG

1917 ◽  
Vol 25 (1) ◽  
pp. 129-152 ◽  
Author(s):  
Edwards A. Park
Keyword(s):  
Guinea Pig ◽  
Serial Section ◽  
Guinea Pigs ◽  
Close Association ◽  
Main Lobe ◽  
Technical Error ◽  
Serial Sections ◽  
Pharyngeal Pouch ◽  
The Third ◽  
Third Pharyngeal Pouch

1. Accessory lobes of thymus, derived from the third pharyngeal pouch, occurring in close association with the parathyroids from the third pouch, were found in serial section of the cervical tissues of eleven out of fourteen guinea pigs, and probably would have been found in all fourteen but for a technical error. 2. It is probable, therefore, that accessory lobes of thymus having this situation and origin are usually, if not always, present in the guinea pig. 3. Additional accessory lobes of thymus belonging to, but at some distance from the main lobe were also present in several of the animals. 4. The discovery of these accessory lobes makes it certain that the guinea pig is unsuitable material for complete thymectomy, and probably complete extirpation of the thymus in this animal is rarely, if ever accomplished. 5. The extirpation experiments of previous investigators in the guinea pig must now be regarded as partial extirpations, and their results interpreted in that light. 6. Extirpation of the thymus in the guinea pig produced no changes in the writer's experiments. 7. The study of the serial sections of the cervical tissues of the guinea pig indicates that Ruben's statements regarding the parathyroid derived from the fourth pharyngeal pouch in the guinea pig are correct,—that it is much smaller than parathyroid III, may be rudimentary, and is sometimes absent at least on one side. 8. No accessory lobe of thymus was found accompanying the parathyroid from the fourth pouch, a finding also bearing out Ruben's statement that no thymus anlarge springs from the fourth pouch in the guinea pig.

Elastic properties of single elastic fibers

1962 ◽  
Vol 17 (3) ◽  
pp. 547-551 ◽  
Author(s):  
Robert W. Carton ◽  
John Dainauskas ◽  
John W. Clark
Keyword(s):  
Connective Tissue ◽  
Elastic Properties ◽  
Constant Temperature ◽  
Exponential Function ◽  
Elastic System ◽  
Elastic Fibers ◽  
Elastic Tissue ◽  
Elastic Network ◽  
Single Fibers ◽  
Applied Tension

The elastic properties of elastic tissue were studied in a situation which minimized the effects of extraneous connective tissue and of the position of fibers in the elastic network. Single elastic fibers were dissected free from the ligamentum nuchae of the ox and were stretched under conditions of constant temperature and salinity. The strain was an exponential function of the applied tension. Single fibers were found somewhat less stretchable than the ligaments from which they were taken. The data given can be used to calculate the contribution of such elastic fibers to the behavior of an elastic system in which they are incorporated. Submitted on August 7, 1961

Fanning the Embers

2016 ◽  
Author(s):  
Rebecca J. Kinney
Keyword(s):  
Connective Tissue ◽  
Auto Industry ◽  
The Third ◽  
The Future ◽  
The Face

The third chapter examines the story of Detroit’s rebirth through both a reliance on its storied past and the possibilities of the future through an examination of a wildly successful commercial starring Eminem. It provides the connective tissue between the storied past of Detroitas as a location of workers and the contemporary narrative of a city on the rise. At its center is the mythic tale provided by the 2011 Chrysler “Born of Fire” commercial. The narrative tale of a rebirth of a city, and by extension the American auto industry, in the face of epic decline makes the story of Detroit the ultimate comeback tale—a phoenix rising from the ashes of destruction.

Grafts of the Third Branchial Arch in Chick Embryos

1996 ◽  
Vol 155 (2) ◽  
pp. 73-80 ◽  
Author(s):  
J.A.M. M&eacute;rida-Velasco ◽  
I. S&aacute;nchez-Montesinos ◽  
J.E. Esp&iacute;n-Ferra ◽  
J.D. Garcia-Garcia ◽  
V. Rolddn-Schilling
Keyword(s):  
Branchial Arch ◽  
Chick Embryos ◽  
The Third

Toward a kinetic theory of connective tissue micromechanics

1993 ◽  
Vol 74 (2) ◽  
pp. 665-681 ◽  
Author(s):  
S. M. Mijailovich ◽  
D. Stamenovic ◽  
J. J. Fredberg
Keyword(s):  
Connective Tissue ◽  
Three Dimensional ◽  
Elastic Fibers ◽  
Tissue Elasticity ◽  
Field Equations ◽  
Fiber Network ◽  
Rate Dependent ◽  
Connective Tissue Matrix ◽  
Tissue Matrix ◽  
And Diffusion

The aim of this study is to develop unifying concepts at the microstructural level to account for macroscopic connective tissue dynamics. We establish the hypothesis that rate-dependent and rate-independent dissipative stresses arise in the interaction among fibers in the connective tissue matrix. A quantitative theoretical analysis is specified in terms of geometry and material properties of connective tissue fibers and surrounding constituents. The analysis leads to the notion of slip and diffusion boundary layers, which become unifying concepts in understanding mechanisms that underlie connective tissue elasticity and energy dissipation during various types of loading. The complex three-dimensional fiber network is simplified to the interaction of two ideally elastic fibers that dissipate energy on slipping interface surfaces. The effects of such interactions are assumed to be expressed in the aggregate matrix. Special solutions of the field equations are obtained analytically, whereas the general solution of the model field equations is obtained numerically. The solutions lead to predictions of tissue behavior that are qualitatively, if not quantitatively, consistent with reports of a variety of dynamic moduli, their dependencies on the rate and amplitude of load application, and some features associated with preconditioning.

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