bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lymphatic endothelium isolation, characterization and long term culture
Authors: Leak Lee V. , Jones Michael 
Published: February 2005

AbstractUsing a collagenase trypsin‐EDTA treatment, we have been able to successfully isolate and grow primary cultures of the lymphatic endothelium (LEC) that were subcultured, frozen for storage, subsequently thawed with good recovery and growth, and serially subcultured. The morphological features of cultured LEC were consistent with that observed for the endothelium of intact lymphatic vessels. A prominent feature of growing cultures was the appearance of large vacuoles in the perinuclear region of the cytoplasm, which became filled with fluid and cell debris engulfed from the culture medium. The basal cell surface lacked a well defined basal lamina and anchoring filaments were observed extending from the basal plasmalemmal surface into the underlying substratum. LEC in cultures were also positive for Factor VIII‐related antigen. However, specific granules, characteristic of Weibel‐Palade bodies were not observed in ultrathin sections of confluent cultures. F‐actin was identified in LEC cultures using fluorescein phalloidin, and in confluent cultures actin filaments were located at the periphery of the cell as a continuous circumferential thin band and short filamentous bundles in the central part of the cell. By using heparin and endothelial cell growth supplement in the culture medium we have been able to grow stable cultures of lymphatic endothelial cells that could be maintained when serially subcultured for over two years. These LEC cultures provide an in vitro model for investigating the function and biochemical properties of the lymphatic endothelium. © 1993 Wiley‐Liss, Inc.
Transport pathways for macromolecules in the aortic endothelium: I. Transendothelial channels revealed by three‐dimensional reconstruction using serial sections
Authors: Ogawa Kazushige , Watabe Tomoyoshi , Taniguchi Kazuyuki 
Published: February 2005

AbstractThree‐dimensional organization of structures labeled by horseradish peroxidase as a tracer molecule in rat aortic endothelium was examined to elucidate the transport pathways for macromolecules. Aortic endothelium was divisible morphologically into four distinct parts, i.e., the parajunctional region (JR), peripheral region (PR), organelle region (OR), and nuclear region (NR). Almost all vesicles, intercellular clefts, and phagosomes were labeled by horseradish peroxidase. Peroxidase‐positive vesicles tended to gather in the PR, occasional JR, and the upper part of the NR. Ultrathin serial micrographs revealed the transcellular channels composed of vesicles in the PR and JR, and the paracellular channels composed of the intercellular cleft without constrictions of tight and gap junctions. Transcellular channels were subdivided into three morphologically different types, where not only vesicles but invagination of abluminal membrane and intercellular cleft occasionally participated in their formation. Three‐dimensional reconstructions from three series of consecutive electron micrographs revealed that almost all peroxidase‐positive vesicles were connected directly or indirectly with the cell surface. These results indicate that the transcellular and paracellular channels are the transport pathways for macromolecules in the aortic endothelium and may suggest that the “shuttle” hypothesis is unsuitable to explain transport system for macromolecules because it postulates the existence of many free vesicles in the cytoplasm. © 1993 Wiley‐Liss, Inc.
Structure of the Golgi apparatus in stimulated and nonstimulated acinar cells of mammary glands of the rat
Authors: Clermont Y. , Xia L. , Rambourg A. , Turner J. D. , Hermo L. 
Published: February 2005

AbstractThe structural features of the Golgi apparatus of acinar cells of mammary glands were examined with the electron microscope in 3 groups of rats: (1) in lactating female animals at 8 days postpartum, which served as controls; (2) in female rats sacrificed at various intervals from 2 to 30 hours following separation from their 8‐day old pups; and (3) in females separated from their 8‐day‐old pups for a period of 12 hours and returned to their litters for durations of 1, 2, 4, and 8 horus. In animals of group 2, the Golgi stacks remained identical to that of controls between 2 and 8 hours. At 12 hours and later, the Golgi stacks decreased progressively in size, but the number of elements composing the stacks remained similar to that of lactating females and all contained casein submicelles. At 24 and 30 hours, typical secretory granules containing casein micelles disappeared from the trans aspect of the stacks. The earliest and most striking changes observed in the Golgi apparatus of the rats of group 2 took place at 12 hours. At this time, the prosecretory and secretory granules decreased considerably in volume and lost most of their electron‐lucent content. This indicated that the delivery of small molecules, i.e., lactose and H2O, to these structures was soon altered following arrest of the sucking stimulus. In animals of group 3, the size of prosecretory and secretory granules and the amount of their electron‐lucent content reverted to normal at 4 hours. Thus the influx of lactose and H2O into these structures appears to be rapidly restored after returning the pups to their mothers. The decrease in size of the Golgi stacks noted at 12, 18, and 24 hours following arrest of lactation (group 2), was accompanied by an increase in number of small vesicles that formed clusters next to the Golgi stacks and in “wells.” Thus in these regressing Golgi stacks, many of the associated small vesicles appear to arise by vesiculation of the saccules. © 1993 Wiley‐Liss, Inc.
Glucocorticoid regulation of surfactant‐associated proteins in rabbit fetal lung in vivo
Authors: Durham Paul L. , Wohlford‐Lenane Christine L. , Snyder Jeanne M. 
Published: February 2005

AbstractThe effects of a maternally administered synthetic glucocorticoid, betamethasone, on the levels of mRNA for the surfactant proteins SP‐A, SP‐B, and SP‐C and on the levels of SP‐A protein were investigated in day 27 gestational age rabbit fetal lung tissue. Betamethasone administration to the pregnant rabbit caused approximately a twofold increase in the fetal lung level of SP‐A protein and a threefold increase in fetal lung SP‐A mRNA levels when compared to levels in fetuses obtained from saline‐treated or uninjected animals. SP‐B mRNA was increased fourfold in fetal lung tissue obtained from glucocorticoid‐treated pregnant does when compared to levels in fetuses of uninjected pregnant does. However, SP‐B mRNA levels in fetal lung tissue from saline‐injected controls were also significantly elevated, ∼twofold, when compared to fetal lung SP‐B mRNA levels in the uninjected control condition. SP‐C mRNA levels in lung tissue of fetuses from both saline‐injected and betamethasone‐injected pregnant does were increased similarly, ∼twofold, over SP‐C mRNA levels in fetal lung tissue obtained from uninjected control does. These data are suggestive that betamethasone treatment increases fetal lung SP‐A and SP‐B mRNA levels and that maternal stress alone can increase the expression of SP‐B and SP‐C mRNA in rabbit fetal lung tissue. Using in situ hybridization, SP‐A mRNA was shown to be present primarily in alveolar type II cells in fetuses of control and saline‐injected does. However, SP‐A mRNA was easily detected in both alveolar type II cells and bronchiolar epithelial cells of rabbit fetal lung tissue following maternal betamethasone treatment. In contrast, SP‐B and SP‐C mRNA were present only in alveolar type II cells of lung tissue obtained from fetuses of control, saline, or betamethasone‐treated does. Thus maternal administration of glucocorticoids increased SP‐A protein as well as SP‐A and SP‐B mRNA levels in rabbit fetal lung tissue. SP‐A mRNA was localized to both alveolar type II cells and in smaller amounts in bronchiolar epithelial cells of rabbit fetal lung tissue. However, SP‐B and SP‐C mRNA were detected only in alveolar type II cells. © 1993 Wiley‐Liss, Inc.
Cardiac neural crest contribution to the pulmonary artery and sixth aortic arch artery complex in chick embryos aged 6 to 18 days
Authors: Waldo Karen L. , Kirby Margaret L. 
Published: February 2005

AbstractPrevious studies of cardiac neural crest (CNC) migration in early chick embryos demonstrated CNC cells in the media of pharyngeal arch arteries three, four, and six, and in the most proximal part of the developing pulmonary arteries. The objectives of this study were to learn (1) to what extent the CNC is involved in the later development of the pulmonary arteries, (2) how the CNC cells are distributed in the sixth aortic arch artery including the wall of the ductus arteriosus in the older embryo, and (3) what happens to the CNC as the pulmonary artery/sixth arch complex grows into its adult configuration. Quail‐to‐chick chimeras were used to study CNC distribution in embryos aged 6 to 18 days. Controls (undisturbed chick embryos) were collected with chimeras. Each was fixed, processed, sectioned, stained with Feulgen‐Rossenbeck stain, and analyzed. The results demonstrated that CNC disappeared from the proximal pulmonary arteries by embryonic day 9 and played no further role in pulmonary artery development. With the exception of the endothelium, CNC completely filled the wall of the sixth aortic arch artery as far distally as its junction with the dorsal aorta in younger embryos and with the aorta in older embryos, thus suggesting the possibility of proximodistal migration of CNC along the sixth aortic arch. The ductus wall, filled with CNC, was intimately associated with the recurrent laryngeal nerve, also filled with CNC, thereby strongly suggesting a role for CNC in ductal closure. © 1993 Wiley‐Liss, Inc.
Cytologic structures unique to deiters cells of the cochlea
Authors: Spicer Samuel S. , Schulte Bradley A. 
Published: February 2005

AbstractDeiters cells in the gerbil cochlea disclosed unusual ultrastructural features. A sharp transition zone separated the cell body underlying outer hair cells into an upper compartment with numerous organelles and a lower part devoid of structures other than the microtubule stalk. Deiters cells exhibited a unique structure, the rosette complex, which consisted of a core of densely fibrillar trabeculae, enclosed in a filamentous meshwork and surrounded by tubulocisternal endoplasmic reticulum. The dense trabeculae radiated in columns downward from an apical translucent area toward a lucent zone around the nucleus. They also spread to the medial plasmalemma enveloping nerves and upward into the base of the phalanx. Frequent, small Golgi complexes bordered the tubular reticulum. The distinctive mitochondria of Deiters cells frequently paralleled the plasmalemma, revealed an elongated, often arched profile, and contained sparse, longitudinally aligned cristae. The stalk, composed of characteristic microtubule bundles resembling those in pillar cells, ascended from basal to apical plasmalemma of the cell body and into the phalanx and reticular lamina as previously described. The stalk appeared also to ramify into smaller microtubule bundles in apical cytosol penetrating the rosette complex. Nuclei in Deiters cells differed from those in hair cells in their location high in the cell and in showing chromatin dispersion indicative of more active protein synthesis. © 1993 Wiley‐Liss, Inc.
The name cranial ovarian suspensory ligaments in mammalian anatomy should be used only to indicate the structures derived from the foetal cranial mesonephric and gonadal ligaments
Authors: van der Schoot P. 
Published: February 2005

AbstractThe term ovarian suspensory ligament appears ambiguous when human adult anatomy textbooks are compared with human embryology or with general mammalian anatomy textbooks. The term ovarian suspensory ligament in laboratory rodents and domestic animals indicates homologous structures during foetal (the cranial mesonephric and gonadal ligaments) and later life (the cranial mesonephric ligament derivatives). In human foetal anatomy textbooks ovarian suspensory ligament is generally applied to this same ligament. However, in human adult anatomy textbooks ovarian suspensory ligament is widely applied to the part of the (uterine) broad ligament which contains the uterine and ovarian blood and lymphatic vessels and nerves. This inconsistency in human anatomy books raises confusion on the nature of the foetal and adult ovarian suspensory ligaments and inconsistencies in the description of the normal anatomical relationships of the ovaries between humans and other mammals. For the proper understanding of normal gonadal growth and development within the abdomen, it is important to maintain a consistent nomenclature of the cranial ovarian structures. The current practice in veterinary and other mammalian textbooks offers a solid point of departure. © 1993 Wiley‐Liss, Inc.
Vagal nerve maturation in the fetal lamb: An ultrastructural and morphometric study
Authors: Hasan Shabih U. , Sarnat Harvey B. , Auer Roland N. 
Published: February 2005

AbstractThe maturation of the left vagal nerve was studied in the fetal lamb by transmission electron microscopy and by computer‐assisted morphometry of sections of the entire nerve at seven gestational ages between 79 and 145 days (term is 147 days) and in the adult ewe. The number of unmyelinated axons per Schwann cell progressively decreased from 25 to 55 at 79 days to 1 to 5 at near‐term. Unmyelinated axons of various sizes were enclosed within a single Schwann cell at all ages, but the mean axonal diameter increased in inverse relation to the number of unmyelinated axons. A few Schwann cells enclosed two myelinated axons, but in most instances myelination did not begin until a 1:1 ratio was achieved; some single axons with a Schwann cell remained unmyelinated in the adult. Myelinated fibers were rare at 79 days but myelination progressed rapidly thereafter until the adult ratio of myelinated: unmyelinated fibers was reached at about 100 days; myelinated axons were not uniformly distributed. The myelin sheaths and axons of small fibers progressively increased in diameter in late gestation, but new large fibers were not added. Early myelinating fibers and immature unmyelinated axons contained more microtubules than neurofilaments; neurofilaments predominated in mature axons with or without myelin. Cross‐linkages between neurofilaments were already evident by 79 days. Maturation of the vagal nerve thus occurs first by an increase in number of myelinated fibers and then by an increase in the size of each fiber in this fixed population. The bimodal distribution in the size histogram of myelinated fibers is not achieved until 134 days gestation and correlates well with physiological maturation of respiratory patterns. © 1993 Wiley‐Liss, Inc.
Functional morphology of the vascular plexuses associated with the cetacean uterus
Authors: Rommel Sentiel A. , Ann Pabst D. , McLellan William A. 
Published: February 2005

AbstractThe cetacean reproductive system is surrounded by thermogenic locomotory muscle and insulating blubber. This arrangement suggests elevated temperatures at the uterus that could induce detrimental effects on fetal development. We present anatomical evidence for a complex countercurrent heat exchange system that could function to regulate the thermal environment of the uterus and a developing fetus. Cooled venous blood from the surfaces of the dorsal fin and flukes enters the abdominal cavity via the lumbo‐caudal venous plexus. This plexus is juxtaposed to the arterial and venous plexuses associated with the uterus. The morphology of the lumbo‐caudal venous plexus suggests that it acts as a “heat sink” for the adjacent tissues. Heat may be transferred to the cool, lumbo‐caudal venous plexus from the warm blood in the arterial and venous plexuses supplying the uterus. Heat may also be transferred from adjacent locomotory muscles to the cool lumbo‐caudal venous plexus. The countercurrent heat exchanger created by the juxtaposition of the lumbo‐caudal venous plexus with the uterovarian arterial plexus is similar in design to that of the countercurrent heat exchanger described for male cetaceans. The functional implications of introducing cool superficial blood into the abdominal cavity of a diving, and locomoting female cetacean are discussed. © 1993 Wiley‐Liss, Inc.
Differentiation of clara cells and pneumocytes of the rat by means of enzyme‐ and immunohistochemistry
Authors: Kudo Shigeharu 
Published: February 2005

AbstractLocalization of non‐specific esterases, Cu‐Zn superoxide dismutase and dehydropeptidase‐I, in rat lung was investigated enzymecytochemically or immunohistochemically. Esterase was demonstrated in Clara cells, type II pneumocytes, and septal cells (or vitamin A‐storing lung cells), to a somewhat lesser extent in type I pneumocytes and ciliated epithelial cells of the bronchioles, and to a minor extent in interstitial fibroblasts of the alveolar septum. Large amounts of esterase reaction product were deposited in the rough endoplasmic reticulum and the nuclear envelope in Clara cells, type II pneumocytes, and septal cells, in addition to smaller amounts in other organelles. No reaction product was found in macrophages (histiocytes) in alveolar septi and alveolar macrophages, except for the primary lysosomes or phagolysosomes and trace amounts in the Golgi vesicles, and none in endothelial cells of alveolar blood capillaries, except for primary lysosomes. Immunolocalization of Cu‐Zn superoxide dismutase was generally limited to a particular area of Clara cells. A constriction occurred in the apical cytoplasm of Clara cells between an immunoreactive dome‐like protrusion and the non‐immunoreactive cytoplasm of the supranuclear area, and the dome‐like protrusion appereared to be pinched off in a ball‐like or oval from. Immunolocalization of dehydropeptidase‐I was demonstrated in a dome‐like protrusion or supranuclear area of Clara cells or throughout the cytoplasm and in the surface plasma membrane of mesothelial cells. The presence of these enzymes in Clara cells suggests a contribution to the detoxification system of the lung, together with cytochrome p‐450‐dependent monooxygenase systems. © 1994 Wiley‐Liss, Inc.
Neoformation of blood vessels in association with rat lung fibrosis induced by bleomycin
Authors: Peão Mário N. D. , Águas Artur P. , de Sá Carlos M. , Grande Nuno R. 
Published: February 2005

AbstractWe have used intratracheal instillation of bleomycin in rats to study the microanatomical changes of blood vessels associated with lung fibrosis. Bleomycin is a toxic cytostatic drug employed in classical models of lung fibrosis. Wistar rats were submitted to intratracheal injection of 1.5 units of bleomycin and sacrificed 2.5 months later, a timing when marked fibrosis of the lung is observed. We casted the vascular tree of the rat lungs by perfusion with a methacrylate resin. These caste were studied by scanning electron microscopy. Lung tissue was also studied by light microscopy and thin section electron microscopy. The major vascular modifications observed in the bleomycin‐treated rats were: (1) neoformation of an elaborate network of vessels located in the peribronchial domains of the lung, and (2) distortion of the architecture of alveolar capillaries. By light microscopy, it was clear that the newly formed vascular network was located in regions of fibrosis (which in the resin casts were digested away). These neoformed vessels appeared to originate from bronchial arteries. Thin section electron microscopy revealed that endothelial cells of the neoformed vessels were plump, presented large nuclei, and showed numerous pinocytotic vesicles that were also observed in subendothelial pericytes. The alveoli of the bleomycin‐treated rats were heterogeneous in size and shape in contrast with the homogeneity of alveoli of control animals. The alveolar capillaries of fibrotic lungs appeared to occupy a larger volume of the alveolar wall than alveolar capillaries of control rats. Our findings indicate that lung fibrosis encompasses marked changes of the vascular system, namely, the neoformation of vessels and the rearrangement of alveolar capillaries. These structural changes suggest that fibrotic transformation of the lung is associated with the local generation of angiogenic stimuli. © 1994 Wiley‐Liss, Inc.
Septation of the respiratory and digestive tracts in human embryos: Crucial role of the tracheoesophageal sulcus
Authors: Sutliff Katharine S. , Hutchins Grover M. 
Published: February 2005

AbstractEsophageal atresia and tracheoesophageal fistula, common malformations of the respiratory and digestive tracts, are of unsettled pathogenesis. Part of the difficulty in understanding these abnormalities arises from the uncertainties about the normal developmental processes in the region. This study examined the development and fate of the tracheoesophageal septum. Normal human embryos from the Carnegie Embryological Collection and fetuses from the Hopkins Pathology Collection were examined, and reconstructions of selected specimens were made from photomicrographs of serial histologic sections. The results show that the lung bud appears in Carnegie stage 12, rapidly enlarges, and bend caudally, thereby producing a sulcus between the foregut and the respiratory system on its caudal aspect. The cranial aspect of this tracheoesophageal sulcus remains fixed at the levels of the first cervical vertebra throughout subsequent embryonic and fetal development. At the same time the trachea and esophagus elongate to bring those parts of the respiratory and digestive systems into their definitive anatomic positions. Examination of the tracheoesophageal sulcus shows that its growth‐limiting properties may be explained by its catenoidal configuration. Catenoidal, or saddle‐shape, sulci have been shown to have similar regional growth‐limiting properties in the embryonic heart. These regions contrast with outwardly convex regions in both the developing heart and lung where growth of the tissues occurs. The observations made here suggest that the origin of the tracheoesophageal malformations must be sought in a configurational abnormality in the area of the developing lung bud in Carnegie stage 12. © 1994 Wiley‐Liss, Inc.
High field magnetic resonance imaging of normal and pathologic human medulla oblongata
Authors: Vandersteen M. , Beuls E. , Gelan J. , Adriaensens P. , Vanormelingen L. , Palmers Y. , Freling G. 
Published: February 2005

AbstractHigh field proton magnetic resonance (MR) imaging has been applied to depict the MR appearaance of the normal excised human cervicomedullary junction, based on which neuropathologic specimens can be described. More specifically, two normal cases and one case of Chiari deformity were imaged in the transverse, sagittal, and coronal dimensions using a 9.4 Tesla vertical bore magnet. The MR images of the normal specimens reveal most of the neuroanatomical microstructures described in literature. An accurate description of the Chiari deformity could be made by comparing the MR reference images with those of the pathologic specimen. All MR detected abnormalities were confirmed by histopathology, by which no additional lesions could be found. © 1994 Wiley‐Liss, Inc.