bluuebunny/crossref_metadata_2025_split huggingface dataset:
The tridimensional structure of Nissl bodies: A stereoscopic study in ventral horn cells of rat spinal cord
Authors: Beaudet Alain , Rambourg Alain 
Published: February 2005

AbstractThe tridimensional structure of rough endoplasmic reticulum was examined with both high and low voltage electron microscopes in large ventral horn cells of rat spinal cord, by combining stereoscopic techniques with the use of thick sections selectively impregnated with heavy metal salts. In all neurons examined Nissl bodies appeared as well defined clusters of densely stained and profusely anastomosed plate‐, ribbon‐, and thread‐like cisternae. Plate‐like cisternae were variable in size, often showed a shallow curvature, and usually ran in short parallel arrays, separated from one another by fairly constant intervals. All gave rise at their edges to several ribbon‐like extensions which occasionally decreased in width distally, turning into thin, thread‐like cisternae. Characteristically, these ribbon‐like structures would emerge at an angle from their plate of origin and smoothly curve away from the plane of the plate to merge with ribbons or threads arising from adjacent or more distant plates. Most plate‐like cisternae were found at the periphery of Nissl bodies and tended to be oriented parallel to their surface. In contrast, the center of Nissl bodies was almost exclusively occupied by a complex network of ribbon‐and thread‐like cisternae. It is suggested that the basic plate/ribbon association here described in spinal motoneurons might be a constant feature of Nissl body architecture in various neuronal types, while the size, orientation, and relative proportion of plate‐like cisternae may vary according to the metabolic state and/or functional specialization of the cells.
Immunolocalization of carbonic anhydrase isozymes in rat and mouse salivary and exorbital lacrimal glands
Authors: Hennigar Randolph A. , Schulte Bradley A. , Spicer Samuel S. 
Published: February 2005

AbstractCarbonic anhydrase (CA) isozyme I and isozyme II have been localized with the immunoperoxidase bridge method in cells of mouse and rat salivary glands and exorbital lacrimal glands. Immunostaining proved optimal in Carnoy fixed specimens for some sites and in Bouin fixed glands for other sites. Staining in mouse largely resembled that in rat glands, but minor species differences were observed. Serous acinar cells in the submandibular gland stained uniformly and exclusively for CA I. From 50 to 100% of the serous acinar cells in the parotid glands evidenced content of both CA I and CA II. A minor population of serous acinar cells in the mouse exorbital lacrimal gland stained for CA I and CA II, but these glands in the rat failed to stain.Immunostaining was observed in ducts in Bouin fixed glands. Some cells in striated ducts of submandibular and sublingual glands stained for CA I and CA II and other cells in these ducts were negative. Such cellular heterogeneity was also observed in excretory ducts of submandibular and sublingual glands. These findings thus demonstrate the presence of CA in two morphologically and functionally diverse cell populations in rodent salivary glands.Immunolocalization of the CA isozymes in serous acinar cells and intercalated duct cells, presumably packaged in secretory granules, implies a role for this enzyme in salivary secretions whereas localization of CA in striated and excretory ducts suggests their traditional function in fluid and electrolyte transport.
Freeze‐fracture and lead ion tracer evidence for a paracellular fluid secretory pathway in rat parotid glands
Authors: Simson J. A. V. , Bank H. L. 
Published: February 2005

AbstractThe morphology and permeability of tight junctions of the three major epithelial constituents of rat parotid gland–acinus, intercalated duct, and striated duct–have been examined ultrastructurally. Acinar and intercalated duct junctions (including those surrounding intercellular canaliculi) averaged two to three sealing strands, whereas striated duct junctions had five to eight sealing strands. When the permeability of the junctional complex was probed by means of a recently devised lead ion tracer technique, acinar junctions were found to be very permeable, intercalated duct junctions were somewhat permeable, and striated duct junctions were essentially impermeable to the tracer. Thus, by both morphological and tracer‐permeability criteria, acinar tight junctions appear to be “leaky.” These data provide strong evidence that, in rat parotid glands, a potential paracellular secretory pathway exists in the acinar region for the transepithelial passage of fluid.
A cytochemical study on surface charges and lectin‐binding sites in epididymal and ejaculated spermatozoa of Macaca fascicularis
Authors: Fain‐Maurel M. A. , Dadoune J. P. , Reger J. F. 
Published: February 2005

AbstractChanges in electronegative and electropositive surface charges and in lectin receptors (concanavalin A and wheat germ agglutinin) were investigated on sperm plasma membranes of the monkey (Macaca fascicularis) during epididymal transit and after ejaculation. Electronegative charges at pH 1.8, which were uniformly distributed on the whole plasma membrane of caput epididymal spermatozoa, increased mainly on the postacrosomal cap and the tail during epididymal passage. Electropositive charges at pH 9 were simultaneously found on the whole cell surface of caput epididymal spermatozoa with a stronger labeling on the acrosomal apex, the postacrosomal cap, and the tail. These charges disappeared during passage through the epididymis corpus. The surface distribution of lectin receptors varied inversely during epididymal transit with an increase in concanavalin A receptors and a decrease in wheat germ agglutinin receptors. These data show that changes in the monkey sperm plasma membrane during epididymal maturation occur in the distal corpus of the epididymis.
Seasonal changes in fine structure of the ductuli efferentes of the ground squirrel, Citellus lateralis (say)
Authors: Pundey Jeffrey , Fawcett Don W. 
Published: February 2005

AbstractThe morphoogical changes that the ductuli efferentes undergo during the seasonal breeding cycle of the ground squirrel Citellus lateralis were examined by means of electron microscopy. At the time of spermatogeneetic activity the epithelium of the ductuli was composed of highly differntiated principal and ciliated cells. Distinctive cytological features of these cells during this period were the presence of a heterogeneous collection of numerous membrane‐bound granules in principal cells and large accumulation of glygen in ciliated cells. Structurally these cells were specialized for movement of luminal contents and its modification by absorption and possible secretion. With the onset of testicular regression, profound changes occurred in both cell types. Initially the lumen of the ductuli became occluded by masses of apical cytoplasm protruded from principal and ciliated cells as well as by degenerating cells which had been sloughed from the epithelium. This leads eventually, by the time of complete testicular regression, to reduced ductuli containing cells smaller in size with fewer organelles than those present during the period of spermatogenesis. The membrane‐bound granules in principal cells and the accretions of glycogen in ciliated cells had now virtually disappeared. There was, however, a dramatic increase in dense inclusions representing deposits of lipofuchsin. As yet the cellular mechanisms controlling and effecting these dramatic changes in morphological appearance are unknwon.
Pleuroperitoneal canal closure in the rat
Authors: Gattone Vincent H. , Morse Dennis E. 
Published: February 2005

AbstractPleuroperitoneal canal development and closure were studied with light microscopy and transmission and scanning electron microscopy in 12.75‐ to 16‐day fetuses. The major chronological events described in this paper are (1) the caudal tips of the lung buds projecting to the pleuroperitoneal canal (12.75 through 13.50 days); (2) the caudal tips of the lungs becoming situated medial to the canal areas at 14 days; and (3) both canals becoming crescent shaped with a uniform diameter until closure. Concurrently, the developing diaphragm and associated pleuroperitoneal folds assume more caudal positions. Both canal regions are bordered by the liver, lung, gonadal ridge, and suprarenal glands. In addition, on the left side, the stomach and mesogastrium also border the early canal. The right canal closes before the left (right, 14.75–15 days; left, 15–15.25 days).The results suggest that the pleuroperitoneal folds are pushed together, thereby closing the canals. This may be accomplished by one or a combination of the following: (1) enlargement of the liver pushing the ventral fold dorsad and a molding of the liver to the dorsal body wall caudal to the canal; (2) liver and thorax enlargement which appears to pull the dorsal fold taut against the central fold; and (3) a change in the orientation of the canal near the time of closure. Each canal is fully closed by the mergence of the dorsal and ventral fold mesothelia and mesenchyme. This study provides a basis for relating pleuroperitoneal canal development and closure to the surrounding organs and tissues.
Macroanatomy of the renicule of the bowhead whale (Balaena mysticetus)
Authors: Abdelbaki Yahya Z. , Henk William G. , Haldiman Jerrold T. , Albert Thomas F. , Henry Robert W. , Duffield Dennis W. 
Published: February 2005

AbstractThe macroanatomy of renicules and surrounding tissues from the kidneys of five Eskimo‐harvested bowhead whales, Balaena mysticetus, was examined. These renicules are similar in overall structure to those of other cetaceans and intermediate in size. There are several important differences including the presence of arcuate vessels within the sporta perimedularis, the extension of connective tissue from the sporta deep into the peripheral cortex, and the presence of very large, thin‐walled veins that occupy the interrenicular spaces. Arterial and venous plexuses outside the substance of the sporta reported in other cetaceans were not observed in the bowhead.
Immunocytochemical identification of cells containing insulin, glucagon, somatostatin, and pancreatic polypetide in the islets of langerhans of the guinea pig pancreas with light and electron microscopy
Authors: Baskin Denis G. , Gorray Kenneth C. , Fujimoto Wilfred Y. 
Published: February 2005

AbstractCell types contianing insulin, glucagon, somatostatin, and pancreatic polypetide were identified in guinea pig islets with light and electron microscopic immunoperoxidase staining. Cells containing immunostainable insulin (B cells) are located throughout the islets, including the islet periphery, and contain irregularly shaped granules (350–550 nm). Granule contents are of variable opacity and are often fragmented but not crystalloid. Cells containing immunoreactive glucagon (A cells) are found in the interior of islets and contain numerous shperoid electron‐opaque granules (250–350 nm). Cells containing immunoreactive somatostatin(D cells) have elongate, axonlike processes that end adjacent to islet capillaries. D cells, which are very numeous and distributed uniformly throughout the islet parenchyma, contain small spheroid granules (150–250 nm) of pale electron opacity. Cells with immunoreactive pancreatic polypeptide (F cells) are rare in islets but numerous among the exocrine parenchyma. F cells contain pale spheroid granules (100–200 nm). Morphological criteria are reliable indicators for A cells and B cells, but D cells and F cells require immunostaining for positive identification.
An improved perfusion technique for fixation of sheep myocardium
Authors: Smolich J. J. , Canale E. , Campbell G. R. , Walker A. M. , Adamson T. M. , Maloney J. E. 
Published: February 2005

AbstractAlthough sheep have been widely used as models in the study of cardiac physiology, corresponding morphologic and morphometric data are scanty. For meaningful correlation of morphometric data with physiological information, it is desirable that fixation of the heart occur under controlled conditions. This paper describes a technique for in situ, retrograde aortic perfusion fixation of sheep myocardium under conditions of controlled pressure and minimal wastage of fixative. This is achieved by the application of snares around the brachiocephalic trunk and aortic arch, which are tightened at the start of the perfusion. These isolate the ascending aorta and the coronary vasculature from the remainder of the circulation and allow fixation of the whole heart at a controlled pressure. The method produces good fixation and contrast for transmission electron microscopy and is applicable to late‐gestation fetuses, lambs, and adult sheep.
The facial nucleus of the rat: Representation of facial muscles revealed by retrograde transport of horseradish peroxidase
Authors: Hinrichsen Colin F. L. , Watson Carol D. 
Published: February 2005

AbstractThe representation of facial muscle groups in the facial nucleus of rat was examined by retrograde transport of HRP. Motoneurons supplying muscle groups are arranged in longitudinal columns. Those supplying nasolabial muscles are located in the lateral and ventral intermediate segments, posterior auricular muscles in a medial column, platysma in an intermediate column; the lower lip and ocular muscles are in the ventral and dorsal segments respectively of the intermediate column. The posterior belly of the digastric muscle is supplied by motoneurons extending from the dorsal aspect of the facial nucleus to the caudal pole of the trigeminal motor nucleus.
Developmental age estimated by bone‐length measurement in human fetuses
Authors: Kelemen Endre , Jánossa Margit , Calvo Wenceslao , Fliedner Theodor M. 
Published: February 2005

AbstractThe lengths of 491 long bones of the extremities derived from 193 freshly delivered human fetuses of 7 to 22 weeks fertilization age were measured. Fetuses delivered after spontaneous abortion, twin pregnancy, or known maternal disease were excluded. The correlation between fetal age (measured by crown‐rump length) and bone length was linear. The term “developmental age” was used for bone length‐derived age values. Developmental age can be determined from the length of even a single bone, i.e., when mechanical injury of the delivered fetus inhibits crown‐rump length measurement. The results could aid researchers dealing with human embryology, clinicians performing fetal tissue transplantation, and could be applied in forensic medicine as well.
Postpartum regeneration of the guinea pig endometrium: Relationship to serum estradiol and progesterone concentrations
Authors: Garris David R. 
Published: February 2005

AbstractThe pattern of cell mitotic activity in the uterus of postpartum, pregnant guinea pigs was correlated with the associated changes in serum progesterone and estradiol levels between days 1–8 of pregnancy. Stromal and glandular epithelial mitotic patterns mimicked the associated fluctuations in serum progesterone and estradiol levels, respectively. No changes in myometrial mitotic activity were observed. The luminal epithelial mitotic index was apparently sensitive to the relative change in the ratio of progesterone‐to‐estradiol in circulation. These studies indicate that postpartum, endometrial preparation for blastocyst implantation depends on the proper priming of the uterus by both progesterone and estradiol in the guinea pig.
Pigmented cells in the leptomeninges of the cat
Authors: Morse Dennis E. , Cova John L. 
Published: February 2005

AbstractCells laden with pigment granules are described in the leptomeningeal tissues of the cat and kitten. These cells can be identified consistently by gross observation following vascular perfusion. The fusiform or stellate pigmented cells are most often found in association with the outermost layers of the arteries of the subarachnoid space. They are typically separated from the cerebrospinal fluid by an attenuated layer of pial cells. Vessels that are described as having pigmented cells along their course are the anterior and posterior cerebellar; the anterior, middle, and posterior cerebral; and the basilar. Electron microscopic studies confirm the presence of abundant pigment granules. The pigment granules are the predominant component of the cytoplasm. Few organelles are demonstrable except for a large central nucleus. The data provide suppport for the concept of neural crest contribution to leptomeningeal structures. Identification of this isolated, easily defined population of melanocytes may provide a model for further studies of neural crest distribution as well as experimental approaches to melanogenesis and melanoma production and control.
The secretory pathway in the mouse epididymis as shown by electron microscope radioautography of principal cells exposed to monensin
Authors: Flickinger Charles J. , Wilson Kathleen M. , Gray Helen D. 
Published: February 2005

AbstractThe secretory pathway in principal cells of the mouse epididymis was studied using in vitro labeling and electron microscope radioautography of tissue exposed to the ionophore monensin. After a 5‐minute pulse of 3H‐leucine, control samples of caput epididymidis were incubated in a modified Krebs‐Ringer solution (MKRH medium), while experimental specimens were placed in the same medium, to which 1 μM monensin had been added. At intervals between 5 minutes and 4 hours, samples were fixed and prepared for electron microscope radioautography. Analysis of control specimens revealed heaviest labeling of the rough and the sparsely granulated endoplasmic reticulum early in the experiment followed by a fall in radioactivity, maximal labeling of the Golgi apparatus at 30 minutes, and a pronounced rise in the percentage of grains associated with the apical cell surface and the epididymal lumen beginning 1 hour after administration of precursor. In monensin‐treated epididymides, radioactive material accumulated in the Golgi region while the normal increase in labeling of the apical surface and the lumen was completely inhibited for at least 2 hours. The percentage of grains attributed to coated vesicles was also reduced in samples exposed to monensin. In contrast, labeling patterns of the abundant, sparsely granulated, endoplasmic reticulum and the rough endoplasmic reticulum were very similar in monensin‐treated and control specimens. The concomitant alterations in labeling of the Golgi apparatus and the lumen demonstrate that the Golgi apparatus participates in intracellular transport of secretory proteins in epididymal principal cells, and is not bypassed as previously suggested. The percentage of grains associated with the sparsely granulated endoplasmic reticulum suggests that much of the synthesis of secretory protein in the principal cells occurs in this organelle, and the lack of alteration of its labeling in the presence of a monensin‐induced block at the level of the Golgi apparatus indicates that the sparsely granulated endoplasmic reticulum lies before the Golgi apparatus in the secretory pathway. It is speculated that vesicles play a role in transport of secretory pathway. It is speculated that vesicles play a role in transport of secretory protein from the Golgi apparatus to the lumen.
Immunohistochemical analysis of the distribution of vimentin in human peripheral lymphoid tissues
Authors: Giorno Ralph 
Published: February 2005

AbstractThe distribution of the intermediate filament protein vimentin in peripheral lymphoid tissues was determined using a monoclonal antibody. Frozen sections of tissue were stained using an avidin‐biotin immunoperoxidase method. The antibody stained endothelial cells in spleen, lymph node, and tonsil. Unusual rod‐like structures were revealed in the sinusoid‐lining cells of the spleen. A variety of reticulum cells was detected, including fibroblastic reticulum cells, histiocytic reticulum cells (tingible body macrophages), and splenic marginal zone macrophages. Very few lymphocytes were immunoreactive. Only weak cytoplasmic immunoreactivity was observed in lymphocytes of the periarteriolar lymphocyte sheath of the spleen. The monoclonal antibody employed appears to be of limited usefulness in detecting normal lymphocytes, but is strongly reactive with endothelial structures and some types of reticulum cells.
Ultrasonic microdissection of the mouse mandible: Exposure of the vasculature of alveolar bone and myelinated axons of the pulp
Authors: Johnson Roger B. , Highison Gregory J. 
Published: February 2005

AbstractThe present scanning electron microscopic study describes a new method for the exposure of blood vessels of mouse alveolar bone and myelinated nerves of the dental pulp. This technique differs from others because it does not remove the periodontal ligament, allowing study of the vascular continuity between alveolar bone and periodontal ligament. Fixed and demineralized mandibles are digested with bacterial collagenase (1 mg/ml) at 37°C for 12 hours, exposed to buffered osmium tetroxide for 24 hours, and ultrasonicated at 80 kHz for 5 minutes. The technique demonstrates that the vascular distribution of the interdental and interradicular septa is different. Vessels pass horizontally through the interdental septum and are continuous with vessels of the adjacent periodontal ligament. Vessels of the interradicular septum branch from a central vessel, pass toward the adjacent periodontal ligament, and become continuous with its vessels. Thus, the pattern of vessel distribution of the interdental septum of the mouse has little similarity to that of man or of research animals. The present study provides an improved method for demonstration of bone vasculature and pulpal axons while retaining valuable anatomical landmarks.
Muscle fiber necrosis and regeneration induced by prolonged weight‐lifting exercise in the cat
Authors: Giddings C. J. , Neaves W. B. , Gonyea W. J. 
Published: February 2005

AbstractFor periods ranging from 26 to 87 weeks, the morphological characteristics of the flexor carpi radialis (FCR) muscle were examined in four cats trained to perform weight‐lifting exercise. Four untrained, sex and weight‐matched cats served as controls. The right FCR from each cat was surgically isolated, attached to a tension transducer, and set at its optimal length. The forelimb was perfused with 2% glutaraldehyde in 0.1 M cacodylate buffer. Small bundles of fibers were teased from their origin and insertion tendons and embedded in Epon. Spaced serial sections were used to examine the morphological features of the fibers for trained and control animals. Ultrastructural examination revealed muscle fiber degenerative changes, such as pyknotic nuclei, disruption of the sarcolemma, vacuolation, and disorganization of myofilaments. Such changes were observed at a higher frequency in trained muscle than in control muscle. Spaced serial sections of fiber bundles showed that the degree of degeneration varied along the length of the fiber. Fiber area measurements showed that trained muscle had both larger and smaller fibers than control samples. The very small fibers observed in the trained muscle were considered to be regenerating or “new” fibers since they had not undergone degenerative changes. “Satellite‐like” cells were observed in trained muscle. Such cells resembled satellite cells but also contained developing myofilaments. Since evidence of degeneration‐regeneration was observed in control samples, but at a lower frequency, it was postulated that weight‐lifting exercise accelerates muscle fiber turnover in the cat FCR.