bluuebunny/crossref_metadata_2025_split huggingface dataset:
Trabecular, nasal, branchial, and pericardial cartilages in the sea lamprey, Petromyzon marinus: Fine structure and immunohistochemical detection of elastin
Authors: Wright Glenda M. , Armstrong Leslie A. , Jacques Anna M. , Youson John H. 
Published: February 2005

AbstractImmunohistochemical and ultra‐structural methods were used to examine the distribution of elastin and the fine structure of the trabecular, nasal, branchial, and pericardial cartilages in the sea lamprey, Petromyzon marinus. The cells and matrix, as well as the overall organization of these components, in larval and adult trabecular cartilage resemble those of adult annular and piston cartilages (Wright and You‐son: Am. J. Anat, 107:59–70, 1983) Chondrocytes are similar to those in hyaline cartilage. Lamprin fibrils and matrix granules, but no collagen fibrils, are found in a matrix arranged into pericellular, territorial, and interterritorial zones. Branchial, pericardial, and nasal cartilages differ from trabecular, annular, and piston cartilages in the organization of their matrix and in the structural components of their matrix and perichondria. Furthermore, immunoreactive elastin‐like material is present within the perichondria and peripheral matrices of nasal, branchial, and pericardial cartilages in both larval and adult lampreys. Oxytalan, elaunin, and elastic‐like fibers are dispersed between collagen fibers in the perichondrium. The matrix contains lam‐prin fibrils, matrix granules, and a band of amorphous material, which is reminiscent of elastin, in the periphery bordering the perichondrium.The presence of elastic‐like fibers and elastin‐like material within some lamprey cartilages implies that this protein may have evolved earlier in vertebrate history than has been previously suggested.
Mechanoreceptors in articular tissues
Authors: Zimny Marilyn L. 
Published: February 2005

AbstractThe morphology, distribution, and function of mechanoreceptors in joint capsules, ligaments, knee‐joint menisci, and articular disks of the temporomandibular joints of animals, including humans, have been reviewed. In addition to free nerve endings, three types of joint receptors are present in most animal joints: (1) a Ruffini‐like receptor situated in the capsule, (2) a Golgi tendon organ situated in a ligament; and (3) the encapsulated Pacinian‐like corpuscle. In the anterior cruciate ligament, nerve fibers enter from the subsynovial connective tissue and terminate in receptors. Most of the receptors are found in the distal portion of the ligament. In the meniscus, nerves penetrate the outer and middle one‐third of the body and the horns from the perimeniscal tissue, with a greater concentration at the horns. In the temporomandibular articular disk, the mechanoreceptor density is greatest at the periphery and progressively decreases toward the center. If a joint has an intra‐articular structure, mechanoreceptors undoubtedly are present within it. The concentration of mechanoreceptors appears greater in areas related to the extremes of movement and probably represents the first line of defense in sensing these extremes. These afferent discharges elicit support from discharging mechanoreceptors located in the joint capsule and subsequently from those in the surrounding muscles. This total afferent output alerts the central nervous system of impending injury, which can then be averted through reflex mechanisms.
Vascularization of the telencephalic choroid plexus of a ganoid fish [Acipenser ruthenus (L.)]
Authors: Weiger T. , Lametschwandtner A. , Kotrschal K. , Krautgartner W.‐D. 
Published: February 2005

AbstractThe vascularization of the telencephalic choroid plexus of the sterlet Acipenaer ruthenus, a ganoid fish, was examined by vascular corrosion casting and by light and transmission electron microscopy. The arterial supply is from the dorsal mesencephalic artery via: (1) the ventral choroidal arteries (left and right); (2) the dorsal choroidal arteries (left and right); (3) the caudal choroidal arteries (left and right; (4) the ventral arteries of the dorsal sac; and, from the olfactory arteries, via 5) the rostral choroidal arteries. The venous drainage is mainly through a single main choroidal vein that can take various courses either directly to the anterior cardinal vein or via the middle cerebral vein to the anterior cardinal vein. To a lesser extent, the plexus is drained via the lateral telencephalic veins and the ventral vein of the dorsal sac to the middle cerebral vein. By angioarchitecture and form, the plexus can be subdivided into five distinct parts: the surface network, the median folds, the large lateral folds, the small lateral folds, and the area common to the bottom of the dorsal sac and the telencephalic plexus. Diameters of terminal vessels as measured from vascular corrosion casts and from paraplast, semithin, and ultrathin sections were never less than 10 /xm. It is suggested that the different areas in one plexus may have different functions with respect to secretion and absorption of cerebrospinal fluid.
Ultrastructural study of the alveolar‐capillary membrane and the tubular endoplasmic reticulum in alveolar type I cells of the caprine lung
Authors: Atwal Onkar S. 
Published: February 2005

AbstractThe ultrastructural features of alveolar type I cells of the goat lung were studied by using vascular perfusion and direct airway instillation of fixatives. The morphological features of smooth endo‐plasmic reticulum (SER) were characterized by measuring the diameter of individual SER tubules which conformed in size and appearance to the tubular endoplasmic reticulum (TER) already described in various types of epithelium. The TER appeared as large tubular aggregates in a palisade arrangement; these aggregates ramified into various areas of the extended cytoplasm of alveolar type I cells. The TER also existed as a mixture of short cisternae and vesicles, and glyco‐gen alpha particles were present in the non‐perikar‐yonic portion of the cell. The different forms of TER had varying relationships to the plasmalemma. The interchangable configurations seen in the structure of TER indicated the functional modalities of the cells and were comparable to similar structural modifications in electrolyte‐secreting cells. The role of TER, microtubules, and large populations of endocytic vesicles in the alveolar type I cells in the goat lung is examined in the context of physiological eructation of rumenal gases and the absorption of electrolyte‐rich fluids which escape into the lung at each eructation in ruminants.
Ultrastructure of odontogenic cells during enameloid matrix synthesis in tooth buds from an elasmobranch, Raja erinacae
Authors: Prostak Kenneth S. , Skobe Ziedonis 
Published: February 2005

AbstractThe ultrastructure of the inner epithelial cells (IDE) and odontoblasts in elasmobranch (Raja erinacae) tooth buds was investigated by transmission electron microscopy to determine what contribution each cell type makes to the forming enameloid matrix.Row II, early stage, IDE cells contained few organelles associated with protein synthesis, whereas preodontoblasts appeared competent to initiate extracellular matrix production. Row III IDE cells are also devoid of organelles related to secretory protein synthesis, although these IDE cells accumulated large pools of intracellular glycogen. The glycogen appeared to be packaged into vesicles and exocytosed into the lateral extracellular space toward the forming enameloid matrix.Row III odontoblasts had a morphology consistent with an active protein secretory cell. No procollagen granules were present within the odontoblasts, however, nor were many collagen fibers observed in the enameloid matrix. Instead, non‐collagenous “giant” fibers having 17.5‐nm periodic cross striations were associated with the imaginations of odontoblast cell processes. Giant fibers, which spanned a clear zone adjacent to the odontoblasts, terminated within the enameloid matrix. Smaller 25‐nm‐wide “unit” fibers emanated from the giant fiber tips to form the bulk of the enameloid matrix. The clear zone, which separated the odontoblasts from the enameloid matrix at early stages, diminished in size at later stages until the odontoblast processes were completely embedded in the enameloid matrix. Nascent enameloid crystallites were observed only after a layer of unmineralized predentin was deposited beneath fully formed enameloid matrix.The results suggest that the major constituent of the enameloid matrix in skates is a non‐collagenous protein derived from the odontoblasts. The inner dental epithelial cells appear to contribute large quantities of carbohydrates to the forming enameloid matrix.
Cellular stages in cartilage formation as revealed by morphometry, radioautography and type II collagen immunostaining of the mandibular condyle from weanling rats
Authors: Luder Hans U. , Leblond C. P. , von der Mark K. 
Published: February 2005

AbstractThe role played by cell addition, cell enlargement, and matrix deposition in the endochondral growth of the condyle was assessed in weanling rats by four approaches making use of the light microscope: morphometry, 3H‐thymidine radioautography, 3H‐proline radioautography, and immunostaining for the cartilage‐specific type II collagen.From the articular surface down, the condyle may be divided into five layers made up of cells embedded in a matrix: (1) the articular layer composed of static cells in a matrix rich in fibers presumed to be of type I collagen, (2) the polymorphic cell layer including the progenitor cells from which arise the cells undergoing endochondral changes, (3) the flattened cell layer in which cells produce a precartilagenous matrix devoid of type II collagen while undergoing differentiation in two stages: a “chondroblast” stage and a short “flattened chondrocyte” stage when Intracellular type II collagen elaboration begins, (4) the upper hypertrophic cell layer, in which cells are “typical chondrocytes” that enlarge at a rapid rate, actively produce type II collagen, and deposit it into a cartilagenous matrix, and (5) the lower hypertrophic cell layer, composed of chondrocytes at a stage of terminal enlargement while the cartilagenous matrix is adapting for mineralization.3H‐thymidine radioautographic results indicate that the turnover time of progenitor cells in the polymorphic cell layer is about 2.9 days. The time spent by cells at each stage of development is estimated to be 1.4 days as chondroblasts, 0.5 days as flattened chondrocytes, 2.3 days as the chondrocytes of the upper hypertrophic cell layer, and 1.1 days as those of the lower hypertrophic cell layer.Calculations referring to a 1 × 1‐mm square‐sided column extending from the articular surface to the zone of vascular invasion provide the daily rate of cell addition (0.0077 mm3), extracellular matrix deposition (0.0127 mm3), and cell enlargement (0.0302 mm3). Hence the respective contribution of the three factors to condyle growth is in a ratio of about 1:1.6:4. This result emphasizes the role played by cell enlargement in the overall growth of the condyle.
Cytoarchitecture of muscle in a genetic model of murine diabetes
Authors: Feczko John D. , Klueber Kathleen M. 
Published: February 2005

AbstractAlthough diabetic neuropathy is well documented, diabetic myopathy is not, except for descriptions of diabetic patients with muscular weakness thought to be due to metabolic changes in the muscle. Muscle and nerve are dependent on each other for normal structure and function; since the peripheral nerve is damaged in diabetes, one would expect concomitant changes in the muscle. This study examines the cytoarchitecture of diabetic muscle. The extensor digitorum longus (EDL) muscles from 165‐day‐old C57BL/KsJ db‐m mice were examined using electron microscopy. Morphological analysis of the diabetic EDL revealed that a significant number of the myofibers, examined within the midbelly region of the muscle, exhibited various degrees of degeneration, signs of denervation, and abnormal lipid stores. Both myoneural junctions and muscle spindles showed significant signs of degeneration, denervation, and abnormal structure. Thus the morphologic changes seen could account for the physiologic changes seen in diabetic muscle.
Glycoconjugate histochemistry of the rat fundic gland using Griffonia simplicifolia agglutinin‐II during the development
Authors: Ihida Kaori , Suganuma Tatsuo , Tsutama Shinichiro , Murata Fusayoshi 
Published: February 2005

AbstractThe development and maturation of fundic glands of Wistar rats were studied using Griffonia simplicifolia agglutinin‐II (GSA‐II) histochemistry at the light microscopic and electron microscopic levels.In adult rats, mucous neck cells and cells intermediate between mucous neck cells and chief cells were specifically labeled with GSA‐II, whereas other fundic gland cells were virtually negative.Ontogenetic studies revealed that GSA‐II positive cells appeared at the bottom of the gland by 21 days of gestation. With differentiation and aging, the elongation of the fundic gland continued, and the labeling intensity of the mucous neck cells increased by 3 weeks after birth. Cells intermediate between mucous neck cells and chief cells were discernible from 3 days after birth. Typical mucous neck cells appeared at 3 weeks after birth, when their labeling intensity with colloidal gold (CG) particles approximated that of adults. On the other hand, the reactive cell population gradually moved from the bottom toward the middle portion of the gland. Finally, the reactive cells were localized at the neck portion of the fundic gland.These results suggest that GSA‐II is a valuable marker for studying mucous neck cells and both their precursor cells and their derivatives.
Neural and vascular provisions of rat interscapular brown adipose tissue
Authors: Nnodim Joseph O. , Lever Jeffrey D. 
Published: February 2005

AbstractThe innervation of rat interscapular brown adipose tissue has been studied by light and fluorescence microscopy and electron microscopy after treatment with “false” adrenergic neurotransmitters 5‐ and 6‐hydroxydopamine. The vascular markers neoprene latex and thioflavin S were used to define the blood vascular arrangements within and around the tissue.Catecholaminergic innervation was revealed by fluorescence microscopy at both parenchymal and vasomotor sites. In animals injected with 6‐hydroxydopamine, this catecholaminergic fluorescence was extinguished in the parenchymal nerve distribution and markedly reduced in the vasomotor plexus.Identification of an extensive network of noradrenergic vasomotor and parenchymal nerve terminals was established by electron microscopy after 5‐ and 6‐hydroxydopamine administration, but unmarked terminals were also observed in both distributions. These unmarked terminals might represent an additional nonnoradrenergic nerve supply to interscapular brown adipose tissue.The thoracodorsal veins draining the fat pads are directly tributary to a large median perforating vein, which joins the azygos vein, and are also continuous with the axillary vein. In addition to the recognized vascular distribution pattern of lobular arteries supplying an abundant capillary plexus drained by lobular veins, direct arteriovenous anastomoses were observed within the interscapular brown fat pad. It is postulated that these additional vascular arrangements are determinant in the phenomenal increase in blood flow through brown adipose tissue during metabolic stimulation.
Distribution of microspheres in plantaris muscles of resting and exercising rats as a function of fiber type
Authors: Ong T. C. , Hayes D. A. , Armstrong R. B. 
Published: February 2005

AbstractThe purpose of this study was to determine histologically the distribution of microspheres (MSs) (14 μm), and hence the relative distribution of blood flow, in rat plantaris muscle relative to the fiber types (fast‐twitch‐oxidative‐glycolytic [FOG], fast‐twitch‐glycolytic [FG], and slow‐twitch‐oxidative [SO]). Three conditions were investigated: (1) preexercise standing; (2) treadmill locomotion at 15 m/min (fast walking); and (3) treadmill locomotion at 60 m/min (moderate galloping). The MS suspension (containing 1 × 106 MSs) was infused into the ascending aorta via a catheter in the carotid artery under each of the 3 conditions so that MSs were distributed to the tissues in proportion to their respective blood flows. Sections (20 m̈m) of the plantaris muscle were cut and assayed for reduced nicotinamide adenine dinucleotide tetrazolium reductase (NADH‐TR) and myofibrillar adenosine triphosphatase (ATPase) activities so the fibers could be typed as SO, FOG, or FG. MSs were located in the NADH‐TR sections, and the fibers next to the MSs were classified and counted. The observed numbers of fibers of each type in each condition that were adjacent to MSs were compared to the predicted number of adjacent fibers based on the assumption the MSs were randomly distributed in the tissue. This analysis demonstrated that MSs (and blood flows) were preferentially distributed to SO fibers during preexercise, to SO and FOG fibers during slow locomotion, and to FOG fibers during fast locomotion. The data support the contention that blood flow is distributed in muscles of conscious animals as functions of fiber type and exercise intensity.
Primary olfactory projections and the nervus terminalis in the African lungfish: Implications for the phylogeny of cranial nerves
Authors: von Bartheld Christopher S. , Claas Barbara , Münz Heinrich , Meyer Dietrich L. 
Published: February 2005

AbstractPrimary olfactory and central projections of the nervus terminalis were investigated by injections of horseradish peroxidase into the olfactory epithelium in the African lungfish. In addition, gonadotropin‐releasing hormone (GnRH) immunoreactivity of the nervus terminalis system was investigated. The primary olfactory projections are restricted to the olfactory bulb located at the rostral pole of the telencephalon; they do not extend into caudal parts of the telencephalon. A vomeronasal nerve and an accessory olfactory bulb could not be identified. The nervus terminalis courses through the dorsomedial telencephalon. Major targets include the nucleus of the anterior commissure and the nucleus praeopticus pars superior. Some fibers cross to the contralateral side. A few fibers reach the diencephalon and mesencephalon. No label is present in the “posterior root of the nervus terminalis” (=“Pinkus's nerve” or “nervus praeopticus”). GnRH immunoreactivity is lacking in the “anterior root of the nervus terminalis”, whereas it is abundant in nervus praeopticus (Pinkus's nerve). These findings may suggest that the nervus terminalis system originally consisted of two distinct cranial nerves, which have fused–in evolution–in most vertebrates. Theories of cranial nerve phylogeny are discussed in the light of the assumed “binerval origin” of the nervus terminalis system.
Lesions in the rat soleus muscle following eccentrically biased exercise
Authors: Ogilvie Robert W. , Armstrong Robert B. , Baird Kenneth E. , Bottoms Charles L. 
Published: February 2005

AbstractMorphological changes in skeletal muscle related to lenghening (eccentric) contractions have been noted by several laboratories. However, a systematic examination of skeletal muscle following repetitive ecentric ontractions is lacking. This study was undertaken to study lesions and determine their relative densities in rat soleus muscle 30 min following level or downhill treadmill exercise. Following fixation in situ by vascular perfusion, toluidine‐blue‐stained 1‐μm sections of the muscle samples selected at 73‐μm intervals were scanned with a light microscope. Three types of lesions were noted: focal disruptions in the A‐band, localized dissolution of Z‐lines, and clotting of muscle fibers. Soleus muscle from the caged controls and the tibialis anterior muscle from downhill‐exercised rats were essentially free of lesions. Eighty‐nine percent of the soleus m. lesions in the downhill runner group and 97% of those in the level runner group were A‐band disruptions. A‐band lesion density was significantly higher in the soleus muscle of the downhill runners compared to level runners with the highest incidence in the distal half. A‐band lesion density was lower in soleus muscles from level runners; however, the highest intramuscular incidence was in the proximal rather than the distal end. The results indicate that a disruption of the A‐band is a principal change within some skeletal muscle fibers 30 min following repetitive eccentric contractions.
Phosphoprotein synthesis and secretion by odontoblasts in rat incisors as revealed by electron microscopic radioautography
Authors: Inage Toshihlko , Toda Yoshihlsa 
Published: February 2005

AbstractThe secretory pathway of clentin phosphoproteins in rat incisors was studied by electron microscopic radioautography after the injectionof 3H serine, and the results were compared with those using 3H‐proline as a tracer.Five min after injection of 3H‐serine, radioactivity was found in the rough endoplasmic reticulum. At 10 min, silver grains were observed over the spherical portions of the cisface of the Golgi apparatus. At 20 min after injection, silver grains were seen over the cylindrical portions of the transface of the Golgi apparatus. The secretory granules showed the strongest reaction from 20 min to 1 hr. At 45 min, a significant labeled band appeared at the mineralization front. At 1 hr, the labeling at the mineralization front began to appear in the mineralized dentin, and after 12 hr this labeled band was located within the mineralized dentin.The pathway of 3H‐proline was essentially the, same The pathway of H‐proline movedmrore slowly as that of 3H‐serine, 3H‐proline than 3H‐serine, especially in transit from the rough endoplasmic reticulum to the Golgi apparatus. Secretory granules were heavily labeled from 30 min to 1 hr after injection of 3H‐proline; no labeling was found at the mineralization front at 45 min. The labeling seen initially over the predentin was over the mineralized dentin no earlier than 6 hr after injection.The labeling pattern with 3H‐serine is closely related to the localization of phosphoproteins, whereas the pattern with 3H‐proline reflects the production of collagen rather than of phosphoproteins. The present radioautographic results indicate that dentin phosphoproteins are related to secretory granules and are secreted by Odontoblasts at the mineralization front and also that phosphoproteins are involved in the process of mineralization of the circumpulpal dentin.
Bone cell biology: The regulation of development, structure, and function in the skeleton
Authors: Marks Sandy C. , Popoff Steven N. 
Published: February 2005

AbstractBone cells compose a population of cells of heterogeneous origin but restricted function with respect to matrix formation, mineralization, and resorption. The local, mesenchymal origin of the cells which form the skeleton contrasts with their extraskeletal, hemopoietic relatives under which bone resorption takes place. However, the functions of these two diverse populations are remarkably related and interdependent. Hone cell regulation, presently in its infancy, is a complicated cascade involving a plethora of local and systemic factors, including some components of the skeletal matrices and other organ systems. Thus, any understanding of bone cell regulation is a key ingredient in understanding not only the development, maintenance, and repair of the skeleton but also the prevention and treatment of skeletal disorders.