bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of sex steroids on the development of sexual dimorphism in mouse innominate bone
Authors: Uesugi Yasuo , Taguchi Osamu , Noumura Tetsuo , Iguchi Taisen 
Published: February 2005

AbstractThe sexual dimorphism of the innominate bone was examined in 14 strains of mice. In female mice of all strains, the pubis was significantly longer and thinner than that in the strain‐matched males. In 13 of 14 strains, the ischium in the male was longer and thicker than in the female. In the testicular‐feminized male (Tfm) mouse, the ischium was longer and thinner than that in the wild‐type male, resembling that of the wild‐type female. The pubis of the Tfm mouse was longer than in the wild‐type males. The pubis width in the Tfm mouse was between those of the wild‐type male and female. Gonadectomy at ages of 5, 10, 20, 30, and 60 days in both sexes showed that the ischium develops as the female type when sex hormones are absent. In contrast, postnatal testicular androgen induces the male‐type ischium. Gonadectomy at 60 days had a slight effect on the pubis, indicating that sexual dimorphism of the pubis was determined before 60 days of age. Estrogen receptors (ER) were immunohistochemically demonstrated in bone cells of 0‐ to 60‐day‐old mice. ER was found exclusively in the periosteum of the pubis at the day of birth; however, it appeared in bone cells of all parts of pelvis at 10–60 days. These results indicate that sexual dimorphism of the pubis is consistent for the 14 mouse strains examined, and that the shape of the pubis is determined by sex steroids before 60 days of age. Since ER exist in the bone cells, morphogenesis of the pelvis may be regulated by these sex steroids.© Willey‐Liss, Inc.
Ultrastructure of epididymal interstitial reactions following vasectomy and vasovasostomy
Authors: Flickinger Charles J. , Herr John C. , Sisak John R. , Howards Stuart S. 
Published: February 2005

AbstractThe response of the male reproductive tract to vasectomy includes inflammation of the interstitial tissue of the epididymis. The pathogenesis of epididymal interstitial reactions and characteristics of the responding cells were studied by electron microscopy in Lewis rats at intervals following bilateral vasectomy, vasectomy followed 1 month later by vasovasostomy, or sham operations. In areas of interstitial reaction, numerous macrophages, monocytes, lymphocytes, neutrophils, and plasma cells occupied the connective tissue. Macrophages, containing many lysosomes and vesicles, aggregated and assumed the appearance of epithelioid cells. Processes of adjacent macrophages interdigitated with one another and closely approached the surfaces of lymphocytes. Many plasma cells with distended rough endoplasmic reticulum appeared in the interstitium. The majority of animals in the vasectomy and vasovasostomy groups exhibited epididymal interstitial changes by 2–3 months; the cauda epididymidis was the region most often affected. The ultrastructural features were indicative of chronic granulomatous inflammation and were consistent with an immune response that includes antigen presentation by macrophages to lymphocytes, lymphocyte differentiation, and local antibody production by plasma cells. The nearly complete absence of sperm or recoghizable parts thereof in the interstitial tissue in the areas of the reactions suggests that these lesions formed in response to soluble antigens leaking from the duct. Vasovasostomy was not effective in reversing or retarding epididymal inflammation at the intervals studied. © 1993 Wiley‐Liss, Inc.
Comparative ultrastructural morphometric analysis of atrial specific granules in the bat, mouse, and rat
Authors: Tagoe C. N. B. , Ayettey A. S. , Yates R. D. 
Published: February 2005

AbstractSize, incidence, and volume density of atrial specific granules (ASG) in right atrial cells from five animals each of the rat (average weight 210 g), mouse (average weight 28 g), fruit‐eating bat Megaloglossus woermanni (BMW;average weight 35 g), and the insect‐eating bat Pipistrellus pipistrellus (BPP; average weight 6 g) have been compared via ultrastructural morphometry. In all three parameters of granule measurement, significantly higher figures were obtained in the rodents than in the bats. However, between the rat and the mouse, as also between the two species of bats, no significant differences were noted in any of the measurements. These results therefore do not support the prevalent view that the number and size of the granules decrease with increase in size of the animal species. The low content of ASG in atrial cells of the bats is probably an indication of low demand for the natriuretic hormone of the granule, because, in such animals, and particularly in flight, conservation of fluid and electrolytes is of paramount importance. This suggests that granule content is adapted to fluid and electrolyte regulation in relation to the functional capacity of the animal. We also observed ASG‐like sgtructures in endothelial cells of capillaries of bat tissue but not in rodents. The function of these granules or whether or not they represent atrial specific ones is not clear from the present study. © Wiley‐Liss, Inc.
Distribution, morphology, and central projections of mesencephalic trigeminal neurons in the frog Rana ridibunda
Authors: Muñoz Margarita , Muñoz Alberto , González Agustín 
Published: February 2005

AbstractThe distribution, morphology, and central projections of the mesencephalic trigeminal neurons in the frog Rana ridibunda were studied with tracing techniques. Retrograde tracing with horseradish peroxidase (HRP) or the fluorescent tracer Fluorogold, and anterograde tracing by means of Phaseolus vulgaris leucoagglutinin, the fluorescent dye Dil, and HRP were used. The mesencephalic trigeminal nucleus (MesV) of Rana ridibunda is formed by a population of 100 to 125 unipolar or multipolar cells that are scattered on both sides of the rostral mesencephalic tectum. Subpopulation of Mes V cells were labeled after tracer application to ophthalmic, maxillary, and mandibular trigeminal branches, separately. Differences in the morphology and distribution of cells in these experiments were not evident but the number of neurons labeled via the maxillary nerve was always the highest. Mes V cells have a single central branch that courses caudally in the brainstem. At different levels, it bifurcates into a peripheral branch, which leaves the brain via the trigeminal root, and a descending branch, which terminates in a region in, or close to, the trigeminal motor nucleus and in a supratrigeminal location. The lack of a distinct somatotopy in the distribution of Mes V cells and the lack of projections caudal to the trigeminal motor nucleus as revealed in this study with a wide variety of tracers are in striking contrast to previous data provided for other amphibians. © 1993 Wiley‐Liss, Inc.
Cryofixation of basement membranes followed by freeze substitution or freeze drying demonstrates that they are composed of a tridimensional network of irregular cords
Authors: Chan Franky L. , Inoue Sadayuki , Leblond Charles Philippe 
Published: February 2005

AbstractSince conventional chemical fixation may extract tissue components and thus alter structural organization, cryofixation was used to reexamine the ultrastructure of three thick basement membranes: lens capsule, Reichert's membrane, and Engelbreth‐Holm‐Swarm (EHS) tumor matrix, and two thin basement membranes, those of epididymis and seminiferous tubules. Cryofixation was achieved by slam freezing followed by either freeze substitution in dry acetone containing 1% osmium tetroxide and 0.05% uranyl acetate or freeze drying in a molecular distillation dryer. The results by both procedures demonstrate that thick basement membranes and the lamina densa of thin basement membranes are composed of a network of anastomosing strands referred to as cords. The cords vary in density and distinctiveness, but their thickness averages 3 to 5 nm in every tissue examined. The spaces separating the cords vary within wide limits, but their mean diameter is ∼15 nm in every case. Two other common features are (1) the presence within the network of a few 1.5–3.0‐nm‐thick filaments and (2) 4.5‐nm‐wide sets of parallel lines referred to as double tracks. When these results are compared with those previously described after conventional fixation, no significant difference is observed in either the cord network or the associated filaments and “double tracks.” However, in the thin basement membranes processed by cryofixation, the lamina densa is in direct contact with epithelial cells, whereas, after conventional fixation, the lamina densa is separated from the epithelial cells by a pale layer referred to as lamina lucida or lamina rara. Immunogold labeling of three basement membranes after cryofixation and freeze substitution in acetone containing 0.3% glutaraldehyde yields strong reactions for laminin, type IV collagen, and heparan sulfate proteoglycan. Comparison with previous results indicates that conventional formaldehyde fixation adequately preserves laminin and type IV collagen but causes the loss of some proteoglycan. It is concluded that, except for this loss and the absence of lamina lucida in cryofixed thin basement membranes, the morphological and antigenic features obtained after cryofixation are similar to those observed in the past after conventional fixation. © 1993 Wiley‐Liss, Inc.
Bone growth and periosteal migration control masseter muscle orientation in pigs (Sus scrofa)
Authors: Herring Susan W. , Muhl Zane F. , Obrez Ales 
Published: February 2005

AbstractDuring growth the muscles of mastication alter their lines of action. Research on long bones indicates that the apparent migration of muscle attachments is due to the movement of the periosteum relative to the underlying bone. To assess whether the pig masseter muscle follows the periosteum during growth, implants of titanium granules in a gelatin matrix were placed simultaneously in various parts of the masseter muscle and its periosteal and bony attachments. Growth movements of these tissues were followed radiographically for 2 months. Granule position was verified histologically. Periosteal movement was the dominant growth process at the insertion of the masseter. All implants migrated caudally relative to the mandible. However, a strong position effect was seen dorsoventrally: implants placed high in the ascending ramus migrated dorsally as well as caudally; low implants migrated only caudally. This differential migration, ascribed to the influence of the condyle, accounts for the increasing horizontal orientation of dorsal fibers. A similar differential was seen along the rostrocaudal axis of the ramus. In contrast to the insertion, the origin of the masseter from the zygomatic arch shows no periosteal movement. Rather, the entire bone‐muscle complex becomes displaced by sutural growth, leading to increasing vertical orientation of the masseter. Thus two different aspects of skull growth are responsible for the change in muscle anatomy. © 1993 Wiley‐Liss, Inc.
Developmental differences in the ossification process of the human corpus and ramus mandibulae
Authors: Merida‐Velasco J. A. , Sanchez‐Montesinos I. , Espin‐Ferra J. , Garcia‐Garcia J. D. , Roldan‐Schilling V. 
Published: February 2005

AbstractA correlation was sought between the organization of the dental crest and the ossification of the corpus mandibulae in 14 human embryos and 13 human fetuses. The different types of ossification between the corpus and the ramus mandibulae suggest that the cartilago mandibularis (meckeliensis) guides the formation of the mandibula, while the dental crest acts as a coorganizer. In the area of the foramen mentale, the lamina dentalis begins to invaginate (to give rise to the dental crest), and at this level intramembranous ossification of the corpus mandibulae commences. These findings, together with the presence of the cartilago mandibularis before the appearance of the dental crest, and the fact that the former is seen along the entire length of the mandibula (from the symphysis mandibulae to the capsula otica), support the hypothesis that the dental crest, rather than the cartilago mandibularis, acts as the coorganizer in the corpus mandibulae. © 1993 Wiley‐Liss, Inc.
Diarthroses in the mouse: From different cellular structure to similar joint appearance
Authors: Livene Erella 
Published: February 2005

AbstractThe structure and function of two major joints, the humeroscapular and the squamoso‐mandibular joints in mice, are compared. The specific roles that these two joints fulfill during early postnatal period are reflected in a different cellular organization observed in them. Following maturation, when similar functional needs are stressed upon these two joints, similar homologous structures are detected in both of them. A possible conceptual explanation for these observations and their relatedness to the human equivalent joints are discussed. © 1993 Wiley‐Liss, Inc.
Morphometric study of the human ovary during compartmentalization
Authors: Sforza Chiarella , Ferrario Virgilio F. , De Pol Anto , Marzona Laura , Forni Marco , Forabosco Antonino 
Published: February 2005

AbstractThe volumetric composition of the human ovary during the compartmentalization stage has been investigated using current stereological methods. Eight left ovaries removed from three fetuses (developmental age 20–25 weeks), four neonates, and one 8‐month‐old child all with a 46, XX karyotype, free from malformations of the genital apparatus, were completely cut obtaining serial sections and one 1 μm‐thick section every 1,000 μm was examined. Ovarian volume was 30 mm3 at the 20th week of development, 36 mm3 at the 25th week, 129 mm3 at birth, and 287 mm3 at the eighth postnatal month. The primitive cortical tissue was the largest component of the fetal ovaries (17 mm3, corresponding to 60.2% of the organ). The second component was the interstitium (21% of the organ), followed by the medulla (11.8% of the organ). The primordial follicles occupied a small part of the organs: 1.8 mm3 at 20 weeks and 3.4 mm3 at 25 weeks (respectively 6.7% and 5.4% of the volumes of the relevant ovaries). At birth, most of the organ was composed of interstitial tissue (57 mm3, 44.2% of the volume) followed by the medulla (25 mm3, 20.3% of the volume). The germinal tissue occupied 46 mm3, mainly primitive cortical tissue (14.9% of the ovary) and primordial follicles (16.3% of the ovary), with a minor contribution from the antral follicles (about 3% of the ovary). At 8 months, the somatic tissue formed the majority of the organ (143 mm3 of stroma, corresponding to about 50% of the volume, and 43 mm3 of medulla, about 15% of the volume); the germinal tissue occupied about 101 mm3: most of this volume was given by the antral follicles (28.6% of the ovarian volume). © 1993 Wiley‐Liss, Inc.
Nerve growth factor receptor immunoreactivity in Meissner and Pacinian corpuscles of the human digital skin
Authors: Vega J. A. , Del Valle M. E. , Haro J. J. , Calzada B. , Suarez‐Garnacho S. , Malinovsky L. 
Published: February 2005

AbstractThe presence of nerve growth factor receptors (NGFr) in sensory nerve corpuscles of human digital skin, primarily Meissner and Pacinian corpuscles, was investigated immunohistochemically using two monoclonal antibodies directed against human‐NGFr. To ensure the localization of NGFr immunoreactivity (IR) alternative sections to that processed for NGFr detection were assayed for neurofilament protein (NFP) and S‐100 protein which selectively label the axon and the periaxonic specialized cells (lamellar cells of Meissner's corpuscles; inner‐core cells of Pacinian corpuscles), respectively. Occurrence of NGFr IR was observed in both types of sensory corpuscles. In Meissner's corpuscles NGFr‐IR was found in the lamellar cells, whereas in the Pacinian corpuscles the lamellae of the inner core, outer core, and capsule displayed NGFr IR. Moreover, a positive IR was observed in the central axon of some Pacinian corpuscles. However, remarkable differences were encountered among Pacinian corpuscles in the pattern of NGFr IR distribution. Present results demonstrate puscles in the pattern of NGFr IR distribution. Present results demonstrate the presence of NGFr IR in sensory nerve corpuscles of the human digital skin, suggesting that NGFr could be involved in the concentration of NGF and in the conveying of this molecule from the cutaneous sources to the cell body of NGF‐dependent primary sensory neurons. However, the mechanisms involved in this process remain to be clarified. © 1993 Wiley‐Liss, Inc.
Immunolocalization of collagen type I and laminin in the uterus on days 5 to 8 of embryo implantation in the rat
Authors: Clark Dawn E. , Hurst Peter R. , McLennan Ian S. , Myers Don B. 
Published: February 2005

AbstractThis study investigated the immunohistochemical distribution of collagen type I and laminin during remodeling of the uterine extracellular matrix in response to embryo implantation in the rat. Collagen type I was found to be virtually absent around the embryo on the evening of day 5 of pregnancy. On days 6 to 8 of pregnancy the areas of primary and secondary decidualized tissue contained very little collagen in contrast to the outer nondecidualized stroma and myometrial tissues in which the staining patterns did not appear to alter. Day 8 of pregnancy was also notable for the appearance of collagen type I at the site of the developing placenta. Localization of laminin corresponded to areas of basement membrane and was associated with the redistribution of blood vasculature during implantation. By day 7 laminin staining was diminished in the basal areas of the lumenal epithelium around the implanting embryo. Laminin was also located in a punctate fashion at the margins of the primary decidual cells on day 6 of pregnancy, but by days 7 and 8 this staining pattern was no longer evident. This study has provided further evidence for a decline in a major fibrillar collagen during natural decidualization and also revealed a localized and transient expression of laminin in association with the differentiation of cells during primary decidual formation. © 1993 Wiley‐Liss, Inc.
Short‐term oral phosphate and bone remodeling in beagles
Authors: Shih Mei‐Shu , Anderson Colin 
Published: February 2005

AbstractAttempts to increase bone volume in osteoporotic patients are still in the experimental stage. The coherence therapy, proposed by Frost, suggests that the activated bone units can remodel bone matrix in tandem. The cells (i.e., osteoclast and osteoblast which compose the remodeling units) are manipulated through specific medications timed to each of their duration of actions. The current study was to examine the effect of withdrawal of oral phosphate on bone in ovariectomized dogs.The present report demonstrates the capability of short‐term oral phosphate to activate bone remodeling in the ovariectomized animal model. Results from biochemical and histomorphometric analyses confirm that remodeling units are activated following the release of parathyroid hormone. This transient scenario inflicts a shift of mineral density distribution in cancellous bone matrix of the iliac crest. Nevertheless, the bone remodeling units appear to be synchronized with each other and thus their resorptive and formative phases should be amenable to further pharmacological manipulation. © 1993 Wiley‐Liss, Inc.
The epithelial attachment and the dental junctional epithelium: Ultrastructural features in porcine molars
Authors: Marks S. C. , McKee M. D. , Zalzal S. , Nanci A. 
Published: February 2005

AbstractThe region of epithelial apposition with a tooth surface is the site of an unusual stratified integument, the junctional epithelium, which combines tight attachment to the tooth, cell turnover, tissue permeability, and epithelial versatility into the first line of defense against periodontal destruction by oral pathogens. To better understand the structure and function of the junctional epithelium we have reviewed its developmental and cell biology, and undertaken a multidisciplinary analysis of its composition in the pig, an omnivore whose dietary and dental development and occlusion patterns are similar to the human condition, and which, because of its size, is more readily amenable to experimental manipulation. The porcine junctional epithelium was also compared with this well‐described epithelium in the rat. Morphological analyses by light microscopy and scanning and transmission electron microscopy showed the porcine junctional epithelium and epithelial attachment were similar to that in the rat except that apically, extracellular matrix lamellae associated with the internal basal lamina were more complex, and more coronally there was extensive layering of a dental cuticle‐like material. Biochemical analysis of the porcine junctional epithelium by dissociative extraction and SDSPAGE revealed the presence of some proteins not present in gingival epithelium. Together, these studies show that the porcine junctional epithelium has predictable morphological and biochemical features which establish the pig as an advantageous model to study the basic and clinical biology of this unique epithelium. © 1994 Wiley‐Liss, Inc.
Morphological changes and cellular proliferation in mouse colon during fetal and postnatal development
Authors: Ménard Daniel , Dagenais Pierre , Calvert Raymond 
Published: February 2005

AbstractTo document regional structural and cellular proliferation changes in the developing mouse colon, tissues from fetal, sukling, and weanling mice were analyzed by light microscopy (LM), transmission electron microscopy (TEM), scanning electron microscopy (SEM), [3H]‐thymidine incorporation studies, and radioautography. The proximal and distal colon were studied independently at all ages. At 17–18 days of gestation, the mouse proximal colonic mucosa was projected into high and low longitudinal folds disposed in a V‐shaped pattern. From birth up to 9 days, the mucosal folds observed by SEM can easily be misinterpreted as being a succession of high and low villus‐like structures at LM level. TEM study confirmed the presence of highly specialized absorptive cells in the upper halves of the mucosal folds during this period. No recognizable crypts were noted at birth. Instead, LM and radioautography showed the presence of cell aggregates developing at the base of the epithelium at all levels of the mucosal folds. These cell aggregates evolved into rudimentary crypts giving fully differentiated crypts by day 16 with radiolabeled cells located in the midcrypt portion. As opposed to the proximal segment, a flat mucosa interspersed with well defined short crypts at birth was observed in the distal colon. During the following days, crypts further developed and by 16 days, the radiolabeled epithelial cells were still exclusively located at the base of the crypt. TEM observations illustrated that specialized cells as those found in the proximal segment did not differentiate in this segment. From birth up to 30 days, the labeling indices continuously decreased in the external muscle layer while increasing in the crypt epithelium at different time intervals in both colonic segments. The results show that true villus structures do not develop in proximal colonic mucosa and document regionally related morphological and cellular proliferation changes during mouse colonic maturation. © 1994 Wiley‐Liss, Inc.