bluuebunny/crossref_metadata_2025_split huggingface dataset:
Autoradiographic localization of [3H]‐thymidine incorporation in developing human esophagus
Authors: Arsenault Pierre , Menard Daniel 
Published: February 2005

AbstractCell proliferation in the developing human esophagus was investigated by by autoradiography using organ culture. The sites of [3H]‐thymidine uptake were localized in the epithelium, the mesenchyme, and the muscularis externa of fetal esophageal explants from 10 to 16 weeks of gestation. Proliferating cells were abundant throughout the stratified epithelium at 10 weeks of gestation. Many labeled nuclei in the mesenchyme and the muscular layer were observed. With the development of the stratified columnar ciliated epithelium, a confinement of the proliferating zone in the basal cell layers occurred, and ciliated cells never appeared labeled. The quantitation of proliferating cells showed a labeling index at its highest value between 10 and 12 weeks; this drastically decreased between 12 and 14 weeks' gestation. A similar pattern was noted for the mesenchyme, while the labeling index in the muscularis externa peaked during the 11–14 weeks period. In all fetuses, the highest labeling index was always recorded in the epithelium. The biochemical quantitation of the [3H]‐thymidine uptake into the total esophageal DNA clearly supported the continuous decrease of the cell proliferation determined by autoradiography between 10 and 16 weeks of gestation. The present investigation provides for the first time basic quantitative data regarding cell proliferation during a particular developmental phase of the human esophagus.
Human intervertebral disc: Structure and function
Authors: Humzah M. D. , Soames R. W. 
Published: February 2005

AbstractThis review begins with a brief introduction in which the development, blood supply and innervation of the intervertebral disc is considered, particularly as these may influence the following sections on structure and function. The three regions within the disc—that is, the nucleus pulposus, annulus fibrosus, and cartilage end plates—are considered in some detail. There appears to be no distinct border between the central nucleus pulposus and the outer annulus fibrosus, the main difference being in their fibrous structure. The fluid space is important in the nutrition of the disc, showing plastic deformation and recovery characteristics. The structural elements, both macroscopically and microscopically, together with the biochemical elements, are intimately related to function.The intervertebral disc should not be thought of as a homogeneous and static structure; it has a heterogeneous composition and responds dynamically to applied loads. Neither should it be considered as an isolated structure because it interacts with the vertebral bodies, together constituting the vertebral unit. Furthermore, changes within the disc can, and do, have dramatic effects on vertebral column kinematics. The intervertebral disc is not inactive; it is capable of self‐maintenance; in injury it can repair itself and has considerable regenerative properties.
Variation of mouse intestinal epithelial whole population cell kinetics during the estrous cycle
Authors: Cheng Hazel , Bjerknes Matthew 
Published: February 2005

AbstractThere are contradictory reports on the effect of the estrous cycle on cell proliferation in the intestinal epithelium. We reexamined estrous‐cycle‐related changes in the epithelium by using flow cytometry and Coulter particle counting. We found significant estrous‐cycle‐related variations in both the distribution of epithelial cells through the cell cycle as well as the number of epithelial cells per unit area in mouse jejunal and colonic epithelium.
Presence of glial cells in the rat pineal gland: A light and electron microscopic immunohistochemical study
Authors: Calvo J. , Boya J. , Borregon A. , Garcia‐Mauriño J. E. 
Published: February 2005

AbstractImmunoperoxidase methods for the demonstration of three glial antigens, vimentin, glial fibrillary acidic protein, and S‐100 protein, were applied to routine‐fixed paraffin sections of rat pineal gland. A pre‐embedding electron microscope immunoperoxidase method was also used to study the ultrastructural localization of S‐100 protein in pineal cells. Light and electron microscopic results showed the presence of these antigenic glial markers in the second pineal cell type. The term glial cell is proposed for the second of parenchymatous cell in rat pineal gland.
Early morphogenesis of the canine lens, hyaloid system, and vitreous body
Authors: Boevé M. H. , van der Linde‐Sipman J. S. , Stades F. C. 
Published: February 2005

AbstractThis study deals with the early morphogenesis, from day 25 to day 35 post coitum (D25–D35), of the canine lens, lens capsule intraocular vascular system, and vitreous body. The breeding method used provides a higher accuracy as to the gestational age of the obtained fetuses than employed previously.The development of the lens, the intraocular vascular system, and the vitreous body of the dog's eye is analogous to that in other mammal species. The findings of this study, combined with data obtained from the literature, suggest that the period during which ocular development takes place is earlier in larger mammalian species than in the smaller ones.Previous descriptions of ocular development in other mammalian species, and one in the dog, reported that the development of the lens capsule starts posteriorly and proceeds towards the anterior part of the lens vesicle. In the present study, the periodic acid—Schiff positive anlage of the capsule was observed to fully surround the lens vesicle at D25, a development that is different and earlier than described previously in the dog and different from that described in other mammals. Moreover, a clear thickening of the capsule was not observed until capillaries of the tunica vasculosa lentis had reached its proximity.
Immunocytochemical localization of a kallikrein‐like serin protease (Esterase A) in rat salivary glands
Authors: Simson J. A. V. , Condon J. , Fenters R. , Chao L. , Chao J. 
Published: February 2005

AbstractLight and electron microscopic (EM) immunocytochemical methods have been used to localize arginine esterase A, a kinin‐generating enzyme immunologically similar to tissue kallikrein, in rat salivary glands. Both polyclonal and monoclonal antibodies to arginine esterase A were used in these studies. By means of a polyclonal antiserum, esterase A was found in granular tubules of submandibular glands and in striated ducts of all three major salivary glands, in a distribution similar to that of tissue kallikrein. With recently developed specific monoclonal antibodies to esterease A, this enzyme was localized in the granules of some (but not all) granular convoluted tubule cells (GCT) and along the basal membranes (but not in apical granules) of striated ducts. By an EM immunoperoxidase method, esterase A was localized subcellularly in granules of some GCT cells and along the basal cell membranes of the tubule and duct system. Thus, this enzyme is found in some sites (GCT granules) shared with tissue kallikrein, but in some unique sites, i.e., basal membranes of striated ducts. The polyclonal antibody used in the present study cross‐reacted with tissue kallikrein, but when absorbed with kallikrein, it gave the staining pattern characteristic of monoclonal antibody to esterase A.
Lung lamellar body amphiphilic topography: A morphological evaluation using the continuum theory of liquid crystals: II. Disclinations, edge dislocations, and irregular defects
Authors: Zasadzinski J. A. N. , Stratton C. J. , Rudolphi R. 
Published: February 2005

AbstractThe bilayers in normal mammalian and human lung multilamellar bodies (LMB) are parallel, equally spaced, and continuous—a configuration that minimizes the large elastic strain energy associated with changing the equilibrium bilayer separation and the hydrophobic–hydrophilic repulsion energy between the hydrocarbon tails of phospholipid and the aqueous phase. This ideal behavior is disrupted at a limited population of large Burgers vector edge dislocations dissociated into ± 1/2 disclination pairs. The configuration and interaction of the defects are explained by the continuum theory of liquid crystals and shown to be identical to defects observed in in vitro surfactant liposomes and bilayers. We report the first observations with molecular resolution of the core structure of a liquid crystal dislocation. Defect cores are shown to be located between both headgroups and tailgroups in human LMB, suggesting that both types of core are similar in energy. This may be the result of partitioning of proteins or other nonlipid impurities in the LMB to the defect cores, which might also change the stability of the dislocations to favor their preservation. The edge dislocation defects interact in ways that minimize their overall strain energy. A population of edge dislocations may play an important role in the transport or localization of certain molecules through the lamellar body. Certain defects were observed in lung multilamellar bodies that have not been observed in in vitro systems; these are probably due to the complex, multicomponent nature of the LMB surfactant and the dynamic, in vivo environment of the LMB.
Tracheobronchial epithelium of the sheep: III. Carbohydrate histochemical and cytochemical characterization of secretory epithelial cells
Authors: Mariassy Andrew T. , St. George Judith A. , Nishio Susan J. , Plopper Charles G. 
Published: February 2005

AbstractWe examined histochemically (light microscopy‐LM) and cytochemically (electron microscopy‐EM) the secretory epithelial cells in the tracheobronchial mucosa of sheep. Six morphologically distinct, granule‐containing cells have been described, on the basis of their morphology and airway distribution: four mucous (M1–M4), serous (SC), and Clara (CC). Stereological and morphometric data indicated that M3, M4, SC, and CC were distinctly different from each other and from M1 and M2 cells. Mucous cells M1 and M2 differed in granule morphology. Samples of tracheas, sixth‐generation bronchi, distal bronchi, and terminal bronchioles of 18 adult sheep were examined. At the LM level, methacrylate sections were reacted with an alcian blue (pH 2.5), periodic acid Schiff (PAS) sequence to differentiate neutral from acidic glycoconjugates (GC), and a high‐iron diamine (HID), alcian blue sequence to differentiate sulfated from nonsulfated (sialated) GC. At the EM level the periodic acid–thiocarbohydrazide localized hexose‐rich, neutral GC. Dialyzed iron (DI) and high‐iron diamine localized carboxylated and sulfated GC, respectively. Granules of all but Clara cells were PAS‐positive. All mucous cells contained acidic groups, but only M1 and M4 cells had LM‐detectable sulfated GC. At the ultrastructural level, minimal but discernible HID and LID reaction product was observed on granule profiles of M2, M3, and SC, indicating acidic and sulfated GC not detected at the LM level. Histochemically, the sheep tracheobronchial epithelium was more similar to that of humans than some other examined mammalian species.
Contribution of the golgi apparatus components to the formation of the acrosomic system and chromatoid body in rat spermatids
Authors: Thorne‐Tjomsland G. , Clermont Y. , Hermo L. 
Published: February 2005

AbstractThe cytochemical distribution of two different acid phosphatases, nicotinamide adenine dinucleotide phosphatase (NADPase) and cytidine monophos phatase (CMPase), was analyzed within the Golgi apparatus, acrosomic system, and chromatoid body of early spermatids. Within the saccules composing the Golgi cortex, the phosphatases were localized in specific and nonoverlapping compartments: the cis‐tubular network, or cis‐element, and the first underlying saccule were unreactive for both enzymes, the following four to five saccules were reactive for NADPase, and the last three saccules were reactive for CMPase. Vesicles of various sizes and short membranous tubules, present near the edges of saccules and in the medulla of the Golgi apparatus, were NADPase‐ and/or CMPase‐positive. The acrosomic system showed a weak but significant NADPase reactivity and a strong CMPase reactivity. The vesicles associated with the chromatoid body were reactive for NADPase and/or CMPase. The combined observations indicate that the two cytochemically distinct compartments of the Golgi cortex, the NADPase‐ and CMPase‐positive saccules, independently contribute to the formation of the acrosomic system and the vesicular component of the chromatoid body.
Localization of actin in human, bull, rabbit, and hamster sperm by immunoelectron microscopy
Authors: Flaherty Sean P. , Winfrey Virginia P. , Olson Gary E. 
Published: February 2005

AbstractMammalian spermatozoa have previously been shown to contain actin, but its subcellular localization and function have not been elucidated. In this study, actin has been localized at the ultrastructural level in human, bull, rabbit, and golden hamster spermatozoa by a monoclonal antiactin antibody and a preembedding immunogold labeling technique. Specific labeling was localized 1) around the connecting piece in the neck region of sperm from all four species, although a species‐specific pattern was evident; 2) on the external surface of the fibrous sheath of human sperm; 3) in the perinuclear space underlying the postacrosomal sheath of bull and rabbit sperm; and 4) between the plasma membrane and outer acrosomal membrane along the concave margin of the hamster sperm head. SDS‐PAGE and Western blots immunostained with the monoclonal antibody confirmed the presence of actin in SDS extracts of Percoll‐purified sperm from each species.
Observations of vascularization in the spinal cord of mouse embryos, With special reference to development of boundary membranes and perivascular spaces
Authors: Nakao Taisuke , Ishizawa Akimitsu , Ogawa Reiko 
Published: February 2005

AbstractThe early stages of vascularizations of the spinal cord of the mouse were studied by graphic reconstruction techniques and electron microscopy. Vascular sprouts arise from the perineural vascular plexus (PNVP) to invade the cord of 10‐day embryos. These enter the cord most frequently via the lateral surface between the dorsal root and the ventral root; less frequently, they enter via the ventral and/or dorsal surfaces and anastomose with sprouts that have entered via the lateral surface.During the development of intramedullary blood vessels there are essential changes both in the basal laminae covering the neural parenchyma of the cord and in the relationship between the neural tissue and vascular walls. The basal laminae of the developing spinal cord were classified into three categories. The first is the perineural, external, or primary neural, basal lamina (PNBL), which is the earliest of the three in formation and covers the entire external surface of the cord. The second one is the internal, or secondary neural, basal lamina (INBL), which invests the internal surface of the neural tissue facing the walls of invading blood vessels. The third type is the perivascular basal lamina (PVBL), which surrounds the vascular wall.Blood vessels enter the spinal cord by penetrating the PNBL. Since the PVBL and INBL are absent or incomplete in early stages of vascularization, the neural tissue is in direct contact with intramedullary blood vessels. However, following their development, boundary membranes are formed, separating the neural tissue from neighboring vessels, a situation characteristic of capillaries in the mature CNS. Perivascular spaces are seen along the course of developing vessels and secondarily become continuous with the extramedullary connective tissue space. They are neither artifact nor intramedullary extensions of extramedullary connective tissue space along invading sprouts. The boundary membranes are formed by connection of membrane plaques or by fusion of the INBL and PVBL.
Development of arteries in embryonic chick bone marrow with special reference to the appearance of periarterial granulopoietic sheaths
Authors: Michael Sorrell J. 
Published: February 2005

AbstractArterial development was studied in embryonic chick bone marrow starting on day 11 of incubation and continuing until day 18. Arteries first appear on day 11 as vessels with two components to their wall structure, namely a thin, complete endothelium and a nearly complete pericyte layer. With advancing age, three distinct layers—an endothelium, a complete muscularis, and adventitia—appear. Long, narrow endothelial cells from cellular junctions at their basal surfaces. Smooth muscle cells remain relatively undifferentiated and do not consist of more than three layers even in the largest arteries. The adventitia consists of a hypocellular zone containing fibroblasts and a collagenous extracellular matrix. Unmyelinated nerves are located at the peripheral margin of the adventitia. All of the larger arteries are surrounded by a sheath of heterophilic granulopoietic cells. These cells do not intrude into the adventitia, but basophilic or mast cells often do intrude. The stromal cells of the periarterial granulopoietic sheaths remain as either fibroblastic cells or as multilocular preadipocytes. They, unlike those stromal cells beyond the sheath, never become unilocular adipocytes. By day 18, granulopiesis is restricted to the periarterial sheaths and to the endosteal regions of the marrow. These studies indicate that fibroblastic stromal cells and preadipocytes, but not fully developed adipocytes, support granulopoiesis in the chick marrow. The stromal cells in the periarterial sheaths either represent a subpopulation of cells that do not develop into adipocytes or represent cells whose development into adipocytes is locally inhibited.
Electron microscopic cytochemical localization of Ca‐ATPase in the rod outer segments of the toadBufo marinus
Authors: Davis Walter L. , Hagler H. K. , Farmer Gene R. , Martin James H. , Bridges George 
Published: February 2005

AbstractTransmission electron microscopy and ultracytochemistry were employed in an attempt to localize the enzyme calcium adenosine triphosphatase (Ca‐ATPase) in the rod outer segments (ROS) of the toad retina. Utilizing a one‐step incubation procedure, Ca‐ATPase was identified as an electron‐dense precipitate in the intradiskal spaces of the rod disks (vesicles) of the ROS. Analytical microscopy identified the reaction product as lead phosphate. The formation of the reaction product was dependent on the presence of ATP (the substrate) and calcium ions. However, calcium ions could be substituted for by magnesium ions. In addition, the reaction was vanadate sensitive. The latter is known to inhibit Ca‐ATPase activity. Such data appear to indicate the presence of a Ca‐Mg‐ATPase in association with the rod disks. Since cyclic guanosine monophosphate (cyclic GMP), rather than calcium ions, is currently believed to be the primary intracellular messenger associated with phototransduction, the presence of an ROS Ca‐ATPase may indicate other functions for this cation in the physiology and biochemistry of the visual process. Ca‐ATPase might play a role in directional calcium fluxes between intracellular compartments.
Involvement of cathepsins B and H in lysosomal degradation of horseradish peroxidase endocytosed by the proximal tubule cells of the rat kidney: II. Immunocytochemical studies using protein A‐gold technique applied to conventional and serial sections
Authors: Yokota Sadaki , Kato Keitaro 
Published: February 2005

AbstractImmunoelectron microscopic localizations of cathepsins B and H and injected horseradish peroxidase (HRP) in the lysosomal system of rat kidney proximal tubules were investigated by a protein A‐gold technique. Kidneys were fixed by perfusion at fixed intervals after intravenous injection of HRP. At 5 to 15 minutes after the injection, the endocytic apparatus—including the apical vesicles, tubules, and vacuoles (endosomes)—were stained for HRP, but they were negative for cathepsins. Within 15 to 30 minutes after the HRP injection, HRP‐containing endosomes were fusing with preexisting lysosomes. In the S1 segment, they accumulated in the apical cytoplasm and formed giant phagosomes, which increased markedly in number and size after 1 hour. These phagosomes were composed of a peripheral clear matrix and electron‐dense inclusions. The clear matrix was stained heavily for cathepsins and HRP, whereas the electron‐dense inclusions were consistently negative for cathepsins and HRP. The same results also were obtained after the double‐labeling and serial sectioning techniques. The dense inclusions were fragmented gradually as the phagosomes decreased in size. After 3 hours, the size and number of phagosomes returned to their normal state (before the HRP injection). These results indicate that the endocytic apparatus of the proximal tubule cells does not contain cathepsins. Phagosomes are formed by the fusion of endosomes containing the internalized protein with the preexisting lysosomes. The degradation of HRP in giant phagosomes occurred rapidly. The coexistence of cathepsins B and H with the endocytosed HRP suggests that these cystein proteinases are involved in the degradation of protein in heterophagosomes of the proximal tubule cells.
Existence of vocal folds in the larynx of odontoceti (toothed whales)
Authors: Reidenberg Joy S. , Laitman Jeffrey T. 
Published: February 2005

AbstractOdontocetes (toothed whales) vocalize for communication and echolocation. The mechanisms of sound production, however, remain unclear. Their larynx has long been thought to lack vocal folds and, thus, was considered incapable of generating sounds. This study investigates internal anatomy of the odontocete larynx to: 1) describe the morphology of any fold found, 2) determine any structural homologies between these folds and the vocal folds of terrestrial mammals, and 3) assess their possible function in sound production. Larynges of 24 odontocetes representin ten genera (Delphinus, Stenella, Lagenorhynchus, Tursiops, Grampus, Delphinapterus, Globicephala, Kogia, Mesoplodon, and Phocoena) were studied post mortem. Nine specimens were cut midsagittally, and the remainder were dorsally opened to reveal internal anatomy. Results show that, contrary to established belief, vocal folds are consistently present. They are not isolated bands or “cords” but appear continuous with the internal laryngeal membrane. The attachments of these folds are the same as in terrestrial mammals, thus indicating homology with true mammalian vocal folds. These folds extend from the midline of the thyroid cartilage to the base of the arytenoid cartilages, sometimes to a discrete process. The vocal folds are elongated and oriented in a vertical plane, parallel to airflow direction. Vocal fold morphology varies, appearing as true bifurcated structures, a trifurcated fold, or a single midline fold. Laryngeal ventricles and vestibular folds are also consistently found lateral to the vocal folds. The vocal folds may divide the airstream within the into three separate air currents. Fold vibrations may produce initial laryngeal sounds used in echolocation or communication.
The mouse pericardium: It allows passage of particulate matter from the pleural to the pericardial cavity
Authors: Fukuo Yoshifumi , Nakatani Toshio , Shinohara Harumichi , Matsuda Takeshi 
Published: February 2005

AbstractFrog erythrocytes injected into the pleural cavity of mice reached the pericardial cavity. Pericardial pores that connect the two cavities were the routes of the migration. As soon as 5 minutes after injection, frog erythrocytes were surrounded and phagocytosed by attached macrophages in milky spots facing the pericardial cavity. The pericardial pores may function in an allied self‐defense mechanism between the pleural and pericardial cavities in this species.