Microscopic organisation of the oviducal gland of the holocephalan elephant fish, Callorhynchus milii

2004 ◽  
Vol 55 (2) ◽  
pp. 155 ◽  
Author(s):  
Rachel M. Smith ◽  
Terence I. Walker ◽  
William C. Hamlett
Keyword(s):  
Periodic Acid ◽  
Structure And Function ◽  
Periodic Acid Schiff ◽  
Terminal Zone ◽  
Neutral Sugars ◽  
Vital Component ◽  
And Function ◽  
Sexually Mature ◽  
Egg Capsule ◽  
Acid Glycosaminoglycans

The study of chondrichthyan reproductive biology has a long history, but the structure and function of the holocephalan oviducal glands (OG) is poorly known; these organs are a vital component in the understanding of chondrichthyan life history. Histochemical techniques revealed that a fundamental zonation was evident in the OG of Callorhynchus milii, similar to most elasmobranchs. In sexually mature females, the following zones occurred (anterior to posterior): (1) club zone, periodic acid–Schiff positive (PAS+), indicating glycoprotein or any mucus substance containing neutral sugars, and Alcian blue positive, pH 2.5 (AB+), indicating the presence of sulfated and unsulfated acid glycosaminoglycans and sialoglycoproteins; (2) papillary zone (AB+); (3) baffle zone (PAS–, AB–); and (4) terminal zone (AB++). Using histological and histochemical techniques not used previously with the holocephalan group, we demonstrated that the structure and function of the OG zones were equivalent between oviparous elasmobranchs and C. milii, even though their final egg capsule morphologies differed. It was also evident that the club and papillary zones produce the egg jelly that surrounds the egg and the baffle zone formed the multilaminate egg capsule. Furthermore, the terminal zone had functions associated with sperm storage and the production of fine hairs that decorate the surface of the egg capsule.

scholarly journals Alterations of the thyroid structure and function in experimental hypopinealism

2011 ◽  
Vol 57 (2) ◽  
pp. 32-35
Author(s):  
L A Bondarenko ◽  
L Iu Sergienko ◽  
N N Sotnik ◽  
A N Cherevko
Keyword(s):  
Thyroid Gland ◽  
Structural Changes ◽  
Structure And Function ◽  
Initial Increase ◽  
Histological Structure ◽  
Pituitary Thyroid Axis ◽  
Thyroid Axis ◽  
And Function ◽  
Sexually Mature

The pituitary-thyroid axis of young sexually mature rabbits kept under a 24-hour daylight photoperiod was shown to undergo phase-modulated variations of hormonal activity with its initial increase (during the first month) and subsequent progressive decrease (within 2-5 months after the onset of exposure to light). These changes correlated with the time-dependent fall in the blood T3, T4, and TSH levels. Simultaneously, the animals developed pathological changes in the histological structure of the thyroid gland similar to those in patients with secondary or tertiary hypothyroidism. It is concluded that hormonal and structural changes in the thyroid gland during long-term hypopinealism should be regarded as an experimental model of hypothyroidism of neuroendocrine origin.

scholarly journals Characterization of a high-molecular-weight glycoprotein isolated from the pulmonary secretions of patients with alveolar proteinosis

1979 ◽  
Vol 177 (1) ◽  
pp. 153-158 ◽  
Author(s):  
Saura Sahu ◽  
William S. Lynn
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Periodic Acid ◽  
Sodium Dodecyl ◽  
Periodic Acid Schiff ◽  
Major Band ◽  
Coomassie Blue ◽  
Neutral Sugars ◽  
Alveolar Proteinosis

A high-molecular-weight glycoprotein was isolated, purified and partially characterized from the insoluble pulmonary secretions accumulating in lungs of patients suffering from pulmonary alveolar proteinosis. On electrophoresis in 5% polyacrylamide gel in the presence of sodium dodecyl sulphate and 2-mercaptoethanol, the purified protein gave one major band as detected by Coomassie Blue as well as with periodic acid/Schiff staining. An apparent mol.wt. of 250000 was estimated for this glycoprotein. Amino acid analysis showed that it contains hydroxyproline, and relatively high amounts of glycine, glutamic acid, aspartic acid and leucine. It contains approx. 6% hexose, 3% sialic acid and 2% glucosamine. The neutral sugars are galactose, mannose and fucose. An antiserum prepared in rabbits against this high-molecular-weight glycoprotein cross-reacted with two smaller glycoproteins (mol.wts. 62000 and 36000) isolated from the same pulmonary secretions of these patients. A complementary observation was also made when this large alveolar glycoprotein cross-reacted with an antiserum prepared in rabbits against the smaller glycoprotein (mol.wt. 36000). It appears that this high-molecular-weight glycoprotein may be the precursor of the two smaller glycoproteins present in the same diseased pulmonary secretions.

scholarly journals Histological, surface ultrastructural, and histochemical study of the stomach of red piranha, Pygocentrus nattereri (Kner)

2015 ◽  
Vol 23 (4) ◽  
pp. 205-215 ◽  
Author(s):  
Saroj Kumar Ghosh ◽  
Padmanabha Chakrabarti
Keyword(s):  
Epithelial Cells ◽  
Periodic Acid ◽  
Histological Structure ◽  
Gastric Glands ◽  
Periodic Acid Schiff ◽  
Cardiac Stomach ◽  
Superficial Epithelium ◽  
Pygocentrus Nattereri ◽  
And Function

AbstractThe structural characterization and function of the stomach in the omnivore Pygocentrus nattereri were described using light and scanning electron microscopy. The sac-like stomach was morphologically divided into the cardiac and pyloric regions. The histological structure of the stomach consisted of four layers of the mucosa, submucosa, muscularis, and serosa. The superficial epithelium of the cardiac stomach was lined with columnar epithelial cells and the glandular epithelium contained numerous gastric glands. Gastric glands were completely absent in the pyloric portion. The mucosal surface of the stomach was a meshwork of various folds, provided with oval or rounded columnar epithelial cells which were densely packed with short, stubby microvilli. The occasional presence of conspicuous gastric pits was surrounded by epithelial cells. The localization and chemical nature of acid and neutral mucins in the various cells of the stomach was studied by employing combined the Alcian Blue-Periodic Acid Schiff (AB-PAS) technique. The deposition of glycogen was detected in the gastric glands as well as in the epithelial lining of the stomach. The utmost reactions for protein and tryptophan were recorded in the gastric glands of mucosa. The cellular organization and histochemical characterization of the stomach are discussed in relation to the feeding and digestion of the fish concerned.

scholarly journals Release of intestinal surface-membrane glycoproteins associated with enzyme activity by brief digestion with papain

1971 ◽  
Vol 121 (5) ◽  
pp. 781-789 ◽  
Author(s):  
Gordon G. Forstner
Keyword(s):  
Brush Border ◽  
Gradient Centrifugation ◽  
Periodic Acid ◽  
Polyacrylamide Gel Electrophoresis ◽  
Surface Membrane ◽  
Membrane Glycoproteins ◽  
Periodic Acid Schiff ◽  
Brush Borders ◽  
And Function ◽  
Sepharose 4B

Rat intestinal surface-membrane glycoproteins were labelled by intraperitoneal injection of [1-14C]glucosamine 4h before the animals were killed. At this time, density-gradient centrifugation of disrupted brush borders indicated that glycoprotein radioactivity was distributed identically with sucrase, a plasma-membrane marker. Labelled brush borders were digested by papain for brief time-intervals known to release surface-enzyme particles without disruption of the unit membrane. Digestion for 5min released 90% of the surface sucrase, and almost one-half of the brush-border glycoprotein and label. On Sepharose 4B column chromatography most of the glycoprotein and label emerged as a single peak. This peak contained the most actively labelled glycoprotein in the brush border and was closely associated with maltase, sucrase, β-naphthylamidase and alkaline phosphatase. The peak was partially resolved on polyacrylamide-gel electrophoresis into three bands. Each band contained a distinctive enzyme or enzyme pair, and was labelled by [1-14C]glucosamine. No periodic acid–Schiff-negative protein was observed in the peak material. Glycoproteins susceptible to brief digestion with papain are therefore closely linked to released surface-enzyme particles. Intestinal surface glycoproteins are heterogeneous with respect to molecular weight, electrophoretic mobility and function.

Ultrastructure of the Parotid Gland of the Nine-Banded Armadillo

1977 ◽  
Vol 35 ◽  
pp. 640-641
Author(s):  
J. R. Ruby
Keyword(s):  
Endoplasmic Reticulum ◽  
Parotid Gland ◽  
Periodic Acid ◽  
Acinar Cells ◽  
Duct System ◽  
Parotid Glands ◽  
Dasypus Novemcinctus ◽  
Anterior Portion ◽  
Periodic Acid Schiff ◽  
Thin Sections

Parotid glands were obtained from five adult (four male and one female) armadillos (Dasypus novemcinctus) which were perfusion-fixed. The glands were located in a position similar to that of most mammals. They extended interiorly to the anterior portion of the submandibular gland.In the light microscope, it was noted that the acini were relatively small and stained strongly positive with the periodic acid-Schiff (PAS) and alcian blue techniques, confirming the earlier results of Shackleford (1). Based on these qualities and other structural criteria, these cells have been classified as seromucous (2). The duct system was well developed. There were numerous intercalated ducts and intralobular striated ducts. The striated duct cells contained large amounts of PAS-positive substance.Thin sections revealed that the acinar cells were pyramidal in shape and contained a basally placed, slightly flattened nucleus (Fig. 1). The rough endoplasmic reticulum was also at the base of the cell.

Structure and function of neural networks in the retina

1988 ◽  
Vol 46 ◽  
pp. 26-27
Author(s):  
Peter Sterling
Keyword(s):  
Ganglion Cells ◽  
Three Dimensional ◽  
Structure And Function ◽  
Synaptic Connections ◽  
Visual Axis ◽  
One Dimensional ◽  
Cat Retina ◽  
Ultrathin Sections ◽  
And Function ◽  
Insight Into

The synaptic connections in cat retina that link photoreceptors to ganglion cells have been analyzed quantitatively. Our approach has been to prepare serial, ultrathin sections and photograph en montage at low magnification (˜2000X) in the electron microscope. Six series, 100-300 sections long, have been prepared over the last decade. They derive from different cats but always from the same region of retina, about one degree from the center of the visual axis. The material has been analyzed by reconstructing adjacent neurons in each array and then identifying systematically the synaptic connections between arrays. Most reconstructions were done manually by tracing the outlines of processes in successive sections onto acetate sheets aligned on a cartoonist's jig. The tracings were then digitized, stacked by computer, and printed with the hidden lines removed. The results have provided rather than the usual one-dimensional account of pathways, a three-dimensional account of circuits. From this has emerged insight into the functional architecture.

Osseointegration interface of calcified bone and endosseous implants

1992 ◽  
Vol 50 (2) ◽  
pp. 1096-1097
Author(s):  
K.E. Krizan ◽  
J.E. Laffoon ◽  
M.J. Buckley
Keyword(s):  
Structure And Function ◽  
Titanium Implants ◽  
En Bloc ◽  
Endosseous Implants ◽  
Ultrastructural Studies ◽  
The Past ◽  
Cacodylate Buffer ◽  
One Year ◽  
And Function

With increase use of tissue-integrated prostheses in recent years it is a goal to understand what is happening at the interface between haversion bone and bulk metal. This study uses electron microscopy (EM) techniques to establish parameters for osseointegration (structure and function between bone and nonload-carrying implants) in an animal model. In the past the interface has been evaluated extensively with light microscopy methods. Today researchers are using the EM for ultrastructural studies of the bone tissue and implant responses to an in vivo environment. Under general anesthesia nine adult mongrel dogs received three Brånemark (Nobelpharma) 3.75 × 7 mm titanium implants surgical placed in their left zygomatic arch. After a one year healing period the animals were injected with a routine bone marker (oxytetracycline), euthanized and perfused via aortic cannulation with 3% glutaraldehyde in 0.1M cacodylate buffer pH 7.2. Implants were retrieved en bloc, harvest radiographs made (Fig. 1), and routinely embedded in plastic. Tissue and implants were cut into 300 micron thick wafers, longitudinally to the implant with an Isomet saw and diamond wafering blade [Beuhler] until the center of the implant was reached.

Use of human autoantibodies and immunoelectron microscopy to study structure and function of the nucleolus and nuclear bodies

1992 ◽  
Vol 50 (1) ◽  
pp. 506-507
Author(s):  
Robert L. Ochs
Keyword(s):  
Electron Microscopy ◽  
Structure And Function ◽  
Nuclear Bodies ◽  
Nuclear Interior ◽  
Coiled Bodies ◽  
Interchromatin Granules ◽  
And Function ◽  
Conventional Electron Microscopy ◽  
Perichromatin Granules ◽  
Perichromatin Fibrils

By conventional electron microscopy, the formed elements of the nuclear interior include the nucleolus, chromatin, interchromatin granules, perichromatin granules, perichromatin fibrils, and various types of nuclear bodies (Figs. 1a-c). Of these structures, all have been reasonably well characterized structurally and functionally except for nuclear bodies. The most common types of nuclear bodies are simple nuclear bodies and coiled bodies (Figs. 1a,c). Since nuclear bodies are small in size (0.2-1.0 μm in diameter) and infrequent in number, they are often overlooked or simply not observed in any random thin section. The rat liver hepatocyte in Fig. 1b is a case in point. Historically, nuclear bodies are more prominent in hyperactive cells, they often occur in proximity to nucleoli (Fig. 1c), and sometimes they are observed to “bud off” from the nucleolar surface.

Depletion and Reconstitution of Active E. Coli Ribosomes

1975 ◽  
Vol 33 ◽  
pp. 640-641
Author(s):  
M. Boublik ◽  
W. Hellmann ◽  
F. Jenkins
Keyword(s):  
Protein Biosynthesis ◽  
Large Subunit ◽  
High Resolution Electron Microscopy ◽  
Small Subunit ◽  
Structure And Function ◽  
Biologically Active ◽  
Biological Macromolecules ◽  
E Coli ◽  
Resolution Electron ◽  
And Function

Correlations between structure and function of biological macromolecules have been studied intensively for many years, mostly by indirect methods. High resolution electron microscopy is a unique tool which can provide such information directly by comparing the conformation of biopolymers in their biologically active and inactive state. We have correlated the structure and function of ribosomes, ribonucleoprotein particles which are the site of protein biosynthesis. 70S E. coli ribosomes, used in this experiment, are composed of two subunits - large (50S) and small (30S). The large subunit consists of 34 proteins and two different ribonucleic acid molecules. The small subunit contains 21 proteins and one RNA molecule. All proteins (with the exception of L7 and L12) are present in one copy per ribosome.This study deals with the changes in the fine structure of E. coli ribosomes depleted of proteins L7 and L12. These proteins are unique in many aspects.

Sign in / Sign up

Export Citation Format

Share Document