bluuebunny/crossref_metadata_2025_split huggingface dataset:
The architecture of adventitial elastin in the canine infrarenal aorta
Authors: Haas Kent S. , Phillips Steven J. , Comerota Anthony J. , White John V. 
Published: February 2005

AbstractAlthough the artery wall consists of three distinct layers, only the structures of the intima and media have been well characterized. The adventitia has generally been overlooked. Our examination focused on the organization of elastin and collagen which are the major components of this tunic. Canine infrarenal aortas were excised, stretched to their in vivo length, then pressure fixed in formalin. Transverse, longitudinal, and frontal sections were prepared with specific elastin and collagen stains. Areas of adventitia in these sections were examined with LM, and interconnections between collagen and elastin were photographed at various magnifications. Subsequently, the slides were fractured for attachment to SEM stubs, and the coverslips were demounted. The identical areas were then examined with SEM using the LM micrographs as a guide to identify elastin and collagen. Whole mount aortic ring preparations were digested in formic acid for 72 and 96 h at 45°C to confirm adventitial elastin architecture. The adventitia was organized in alternating lamellae of collagen and elastin. The elastin lamellae consisted of continuous sheets of elastin with a longitudinal fibrillar substructure. Finer circumferential elastin fibers were also identified. These attached to both longitudinal elastin and adjacent collagen lamellae. Collagen lamellae were arranged in broad corrugated bands of fibrils. The unique architecture of the adventitia may explain some of the visco‐elastic properties of the aorta in both normal and pathologic states.
Morphology of the enamel organ in the miniature swine
Authors: McKee M. D. , Aoba T. , Moreno E. C. 
Published: February 2005

AbstractIn recent years, the dentition of the pig has been increasingly used as a model for the study of amelogenesis. Indeed, much of our current knowledge on enamel formation derives from biochemical and physicochemical analyses of the organic and inorganic components, respectively, of porcine enamel. As an extension of this previous work, and as the first step in our attempt to correlate known enamel matrix and mineral changes with adjacent enamel organ morphology, the present study was undertaken to provide a description of the morphological events occurring in the enamel organ during porcine amelogenesis. Two‐week‐old miniature swine (minipigs) were fixed by vascular perfusion with glutaraldehyde, the deciduous teeth present at this age were embedded in Epon resin and sectioned, and the cells of the enamel organ at each of the various developmental stages of amelogenesis were examined by light and transmission electron microscopy. In many respects, the morphology of the porcine enamel organ was similar to that previously described in other mammalian species. On the other hand, several particularities were noted and these are discussed in the context of available data correlating cell ultrastructure with putative function during enamel formation.
Immunohistochemical comparison of T‐cell and macrophage populations in mammary tissue of control and Trichinella spirails‐infected rats
Authors: Kumar Shantha N. , Steven William M. , Stewart George L. , Seelig Leonard L. 
Published: February 2005

AbstractWe have shown that antigen‐specific T lymphocytes can mediate maternal‐to‐neonatal immunity during lactation. Present studies address the dynamics of lymphocyte accumulation in the mammary gland during normal and disease stimulated conditions. Monoclonal antibodies specific for total T cells, suppressor/cytotoxic and helper subsets, and macrophages were used in conjunction with immunohistochemistry to identify and count the individual cell types. In unstimulated mammary tissue, following a rise in T cells to maximal numbers in late pregnancy, the total number of T cells/high power field (HPF) was significantly diminished in early lactation and continued to decline to the late lactation period. Both the numbers of T cells/HPF located in the mammary alveolar epithelium and surrounding connective tissue were significantly reduced in early lactation as compared to late pregnancy. This indicates the possible passage of cells into the milk during lactation. Prior infection of the mother with Trichinella spiralis and a secondary challenge 48 h. before sacrifice caused a significant reduction in the number of T cells in the mammary tissue in early lactation as compared with unstimulated controls, indicating the possibility of an even greater outflow of T cells into milk. In controls, the T‐suppressor/cytotoxic subtype showed a reduction in early lactation versus late pregnancy but showed no shifts in total cells/HPF during infection. The T‐helper subtype in controls remained unchanged from late pregnancy to early lactation with a considerable decline in late lactation. However, the T‐helper cells were significantly decreased in T. spiralis‐treated animals as compared with noninfected controls in early lactation. The population of macrophages declined from late pregnancy to early lactation but remained unchanged between normal and T. spiralis‐infected animals.
Differential distribution of salivary agglutinin and amylase in the Golgi apparatus and secretory granules of human salivary gland acinar cells
Authors: Takano Kunio , Bogert Meredith , Malamud Daniel , Lally Edward , Hand Arthur R. 
Published: February 2005

AbstractThe secretory granules of salivary glands often display complex internal substructures, yet little is known of the molecular organization of their contents or the mechanisms involved in packaging of the secretory proteins. We used post‐embedding immunogold labeling with antibodies to two secretory proteins, agglutinin and α‐amylase, to determine their distribution in the Golgi apparatus and secretory granules of the human submandibular gland acinar cells. With monoclonal antibodies specific for carbohydrate epitopes of the agglutinin, reactivity was found in the trans Golgi saccules, trans Golgi network, and immature and mature secretory granules. In the granules, labeling was seen in regions of low and medium electron density, but not in the dense cores. Reactivity seen on the apical and basolateral membranes of acinar and duct cells was attributed to a shared epitope on a membrane glycoprotein. Labeling with a polyclonal antibody to amylase was found in the Golgi saccules, immature and mature secretory granules, but not in the trans Golgi network. In the granules, amylase was present in the dense cores and in areas of medium density, but not in the regions of low density. These results indicate that these two proteins are distributed differently within the secretory granules, and suggest that they follow separate pathways between the Golgi apparatus and forming secretory granules. Small vesicles and tubular structures that labeled only with the antibodies to the agglutinin were observed on both faces of the Golgi apparatus and in the vicinity of the cell membrane. These structures may represent constitutive secretion vesicles involved in transport of the putative membrane glycoprotein to the cell membrane.
A fine morphological study of germ cells in asymmetrically developing right and left ovaries of the chick
Authors: Ukeshima Atsumi , Fujimoto Toyoaki 
Published: February 2005

AbstractGerm cells of the chick ovary which develop asymmetrically on the right and left sides of the embryo were observed by electron microscopy from 7 to 17 days of incubation. Germ cells showed different patterns in the right and left‐ovaries, and also differences in the cortex and in the medulla. At 7 to 9 days, germ cells were individually present in both the right and left ovaries. They proliferated from 10 days onward and formed many cell aggregates. In each aggregate, germ cells were joined by intercellular bridges, and their cell cycles were synchronized. Although meiotic features of the germ cells were frequently found in the cortex of the left ovaries at 16 days, some germ cells exhibited these features at earlier days. In the meiotic germ cells, the “Balbiani body,” which was composed of a concentration of cell organelles shifted to one pole of the cell, was always seen. The apperance of a meiotic nucleus and Balbiani body was characteristic of germ cells located in the left ovarian cortex, whereas those were never seen in the left medulla and in the right ovary. At 16 and 17 days, some germ cells were released into the lacunae of the medulla of both the right and left ovaries. The meaning of this phenomenon is discussed. Degenerating germ cells were frequently observed in the right ovary, but rarely in the left.
Localization of Calmodulin in perinuclear structures of spermatids and spermatozoa: A comparison of six mammalian species
Authors: Kann Marie‐Louise , Feinberg Jacqueline , Rainteau Dominique , Dadoune Jean‐Pierre , Weinman Serge , Fouquet Jean‐Pierre 
Published: February 2005

AbstractThe distribution of Calmodulin was examined during spermiogenesis and sperm epididymal maturation in rabbit, hamster, mouse, rat, monkey, and human. An affinity‐purified antibody to Calmodulin was used to characterize this protein in sperm extracts by immunoblot analysis. Post‐embedding immunogold procedures were used to localize Calmodulin at the ultrastructural level. The pattern of Calmodulin distribution was similar in the six species studied. A diffuse labeling was observed in round spermatids. Gold particles accumulated first in the subacrosomal layer of elongating spermatids. The perinuclear ring was also labeled. During the maturation phase of spermatids, Calmodulin labeling extended to the postacrosomal sheath. Dramatic changes occurred at spermiation so that in testicular sperm Calmodulin immunostaining was predominant in the postacrosomal sheath. Some labeling was still detected in restricted areas of the subacrosomal layer. This feature varied from species to species. Calmodulin location did not change during sperm epididymal maturation. A role for Calmodulin in the control of manchette development and regulation of subacrosomal actin aggregation state during spermiogenesis is proposed. The unique location of Calmodulin in the postacrosomal sheath of all species that have been studied in this work, together with the known presence of calcium in this area suggest a pivotal role for Calmodulin in sperm‐egg fusion process.
Effect of basicranial flexion on larynx and hyoid position in rats: An experimental study of skull and soft tissue interactions
Authors: Reidenberg Joy S. , Laitman Jeffrey T. 
Published: February 2005

AbstractThe mammalian upper respiratory tract is a functionally dynamic region involved in respiration, deglutition, and phonation. As the structures of this area (e.g., larynx, hyoid) are suspended from the basicranium, changes in basicranial shape may affect both their anatomy and function. Although skeletal/ soft tissue relationships have been examined through descriptive, comparative anatomy, these relationships have remained largely unexplored via experimental study. In this study, mechanical relationships between basicranial shape and positions of the larynx and hyoid bone are investigated experimentally. Skull base flexion was induced by surgically ablating the spheno‐occipital synchondrosis in 13‐day‐old rats. Lateral radiograms were taken at 40, 60, 80, 100, and 120 days, and angular measurements made of basicranial shape and positions of the larynx and hyoid bone. Statistical analysis shows significant differences between experimental and control groups for skull base, hyoid, and larynx angles, and negative (inverse) correlations for basicranial shape change vs. hyoid position, and basicranial shape change vs. larynx position. Results show induced basicranial flexion caused inferior displacement of the larynx and hyoid bone, thus indicating a direct, mechanical relationship between skeletal and soft tissues. These observations may aid in understanding the basic biological, pathological, and evolutionary interactions of hard and soft tissues of the upper respiratory region.
Relationship between the articular surface area of a bone and the magnitude of stress passing through it
Authors: Pal G. P. , Routal R. V. 
Published: February 2005

AbstractThe present study investigates the relationship between the articular area of a bone and the magnitude of the stress it resists. An attempt was also made to find the correlation between the development of a bone and its articular area. The material of the study consisted of a large number of dry, macerated, adult male skeletons. The articular surface area of the bones was measured with the help of a planimeter.The magnitude of the force acting on the proximal articular surface of a bone is expected to go out of the bone through its distal articular surface in almost the same proportion. The present investigation is based on the assumption that if the articular area is related to the magnitude of stress, then the proximal and distal articular areas of a bone should also be correlated. A significant correlation was observed between the proximal and distal articular areas of axis vertebra; L4 and sacrum; and tibia‐fibula and talus. This indicated that the stress resisted by proximal and distal articular areas was in the same proportion. Similarly, a significant positive correlation between bone index and articular area in ribs, tibia, and laminae of vertebrae indicated that the bone mass (development) runs parallel to the articular area. Thus, the present investigation could reveal that the articular area and bone development are related to the stress acting on the bone.
Unusual mitochondria in the hepatocytes of rats treated with a vitamin B12 analogue
Authors: Tandler Bernard , Krahenbuhl Stephan , Brass Eric P. 
Published: February 2005

AbstractAdult male rats were administered hydroxy‐cobalamin (c‐lactam) (HCCL), a vitamin B12 analogue, by means of osmotic mini‐pumps. The metabolic effects of HCCL, are similar to those produced by simple dietary deficiency of vitamin B12 (Frenkel et al., 1976), but the morphological alterations in hepatic mitochondria are quite different in the two treatments. In HCCL‐treated animals, hepatic mitochondria showed significant increases in number. In one rat, the hepatic mitochondria frequently had a single, elongated, circumferentially‐oriented crista, with the inner compartment being occupied by a greatly augmented matrix. Such organelles appeared to be capable of division, as indicated by medially‐partitioned forms. Numerous hooded mitochondria were present in the hepatic cells of the same animal. Almost every mitochondrion of whatever morphology was partially or completely shrouded by a cistern of rough endoplasmic reticulum. These mitochondrial morphological changes may be related to the chronic metabolic changes in this animal model of methylmalonic aciduria.
Physiological and pathophysiological pulmonary responses to inhaled nuisance‐like or fibrogenic dusts
Authors: Warheit David B. , Hansen John F. , Hartsky Mark. A. 
Published: February 2005

AbstractA short‐term bioassay has been developed to assess pulmonary toxicity and predict pathological effects in animals exposed to aerosolized particulates. To test the reliability and predictive value of our bioassay, we have exposed rats to 2 materials with different biological activities. Rats were exposed for 1 or 3 days to selected concentrations of crystalline silica (a known fibrogenic dust), or to carbonyl iron (CI) particles (a material with activity reputedly similar to nuisance dusts). Pulmonary cells and tissues were evaluated at several time points after exposure. In a companion manuscript we reported that brief exposures of silica produced a sustained pulmonary inflammatory response, characterized by increases in biochemical indicators, whereas no significant effects were measured in CI‐exposed animals. In the current study, our results showed that although deposition patterns for the 2 dusts were similar (i.e., at alveolar duct bifurcations), brief doses of silica produced a sustained granulocytic inflammatory response at the sites of particle deposition, while CI particles were phagocytized and cleared from the lung by normal pulmonary macrophage mechanisms which included transport via the airway mucociliary escalator. Light, scanning, and transmission electron microscopy of silica‐exposed lung tissue revealed a chronically active pulmonary inflammatory response characterized by hyperplasia of type II alveolar epithelial cells and the infiltration of pulmonary macrophages and neutrophils into interstitial tissues and alveoli. The lesions were progressive leading to a granulomatous pneumonitis within 2 months postexposure. In contrast to the alterations in pulmonary tissues produced by silica, no CI‐related lesions were detected at any time postexposure. The results justify the utility of this bioassay as a reliable approach to evaluating the pulmonary toxicity of inhaled particulates.
FSH in testes of marmosets during development: Immunocytochemical localization and de novo biosynthesis
Authors: Garde Seema V. , Sheth Anil R. , Kulkarni Sujata A. 
Published: February 2005

AbstractImmunocytochemical localization of FSH was carried out in various cell types of marmoset testes during development using antisera generated against intact as well as β‐subunit of human FSH. Significant differences in the intensity as well as distribution of FSH in various cell types were observed in neonatal, pubertal, and adult marmosets. Intensity of staining in Leydig cells was maximum at day 1 and in adults (1–3 years), whereas it was minimum at 3 months. In seminiferous tubules (Sertoli cells), FSH was present in trace amount until puberty and subsequently increased at maturity. Further studies demonstrate de novo biosynthesis of FSH‐like moiety in vitro by testicular tissue, which was age dependent.
Characterization of the endocrine cells in the pancreatic‐bile duct system of the rat
Authors: Park In‐Sun , Bendayan Moïse 
Published: February 2005

AbstractSix types of endocrine cells showing immunolabelling against gut or pancreatic islet hormones were identified in the pancreatic‐bile duct system of the normal adult rat at the light and electron microscopic levels. They were located within the epithelial lining of the duct system from the intercalated portion to its duodenal opening. However, the distribution and frequency of each endocrine cell varied along the length of the duct system. While insulin, glucagon, somatostatin, and pancreatic polypeptide cells were widely distributed along the entire duct system, small numbers of cholecystokinin and serotonin cells were confined to the terminal portion. A considerable number of somatostatin cells were concentrated in gland‐like pouches of the terminal portion of the common pancreatic‐bile duct. When the accessory pancreatic duct was present, insulin, glucagon, and somatostatin cells were also found in its epithelial lining. Electron microscopically, the specific content of the secretory granules of all endocrine cells was confirmed by immunolabelling or cytochemical staining. Further the characteristics of the secretory granules of each endocrine cell type corresponded to those present in the same kind of endocrine cells in gut or pancreatic islet. The duct endocrine cells displayed a particular ultrastructural appearance. The “open type cells” were highly polarized, with their apical cytoplasmic process reaching the duct lumen, whereas “closed type cells” showed long basal cytoplasmic processes with no connection with the duct lumen. In general, insulin, and somatostatin cells were of the “open type,” while no morphological connection with the duct lumen was found for glucagon and pancreatic polypeptide cells. The presence of various duct endocrine cells with their particular ultrastructural appearance implies that they may take part in modulating the function of the duct system.
Position of the axillary nerve in the deltoid muscle
Authors: Kulkarni Roopa R. , Nandedkar Ashalata N. , Mysorekar V. R. 
Published: February 2005

AbstractThe relationship of the anterior branch of the axillary nerve to the deltoid muscle was studied on both sides in 66 adult cadavers. The nerve runs a course on the deep surface of the deltoid muscle about 2.2 cm above the midpoint on the vertical plane of the muscle.
Fibroblast contraction occurs on release of tension in attached collagen lattices: Dependency on an organized actin cytoskeleton and serum
Authors: Tomasek James J. , Haaksma Carol J. , Eddy Robert J. , Vaughan Melville B. 
Published: February 2005

AbstractThe generation of tension in granulation tissue undergoing contraction is believed to be a cell‐mediated event. In this study we used attached collagen lattices as a model system for studying the cellular mechanisms of tension generation by fibroblasts in an extracellular matrix. Fibroblasts in attached collagen lattices developed stress fibers, surface associated fibronectin fibrils, and a fibronexus‐like transmembrane association interconnecting the two structural components. Release of the attached collagen lattice from its points of attachment resulted in a rapid, symmetrical contraction of the collagen lattice. Rapid contraction occurred within the first 10 minutes after release of the lattice from the substratum, with greater than 70% of the contraction occurring within the first 2 minutes. Rapid contraction resulted in a shortening of the elongate fibroblasts and compaction of the stress fibers with their subsequent disappearance from the cell. Cytochalasin D treatment prior to release disrupted the actin cytoskeleton and completely inhibited rapid contraction. The removal of serum prior to release inhibited rapid contraction, while the re‐addition of serum restored rapid contraction. These results demonstrate that fibroblasts can develop tension in an attached collagen lattice and that upon release of tension the fibroblasts undergo contraction resulting in a rapid contraction of the collagen lattice. Fibroblast contraction is dependent upon an organized actin cytoskeleton and is promoted by the presence of serum.