bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distribution of serotonin‐immunoreactive paraneurons in the lower urinary tract of dogs
Authors: Hanyu Shugo , Iwanaga Toshihiko , Kano Kenichi , Fujita Tsuneo 
Published: February 2005

AbstractMorphological and quantitative studies were made on serotonin‐containing paraneurons throughout the lower urinary tract in male and female dogs. Using an anti‐serotonin antiserum, the cells were consistently demonstrated to be dispersed in the epithelium from the vesico‐urethral junction to the external urethral ostium. They occurred most frequently in the urethra proximal to the urogenital diaphragm in both sexes. The total number of the serotonin‐immunoreactive cells in the urethra, was estimated to be 36.2 × 104 (SD 9.9 × 104 in the male (n=3) and 15.6 × 104 2.1 × 104) in the female (n=3). Besides the urethra, the prostate and vaginal vestibule contained several sero‐tonin‐immunoreactive cells. The urethral serotonin cells were basically bipolar basal‐granulated cells that extended the basal cytoplasm too the basement membrane and reached the lumen with an apical process. Modified cell shapes were, however, also frequent, and included bifurcated apical and/or basal processes or a laterally directed basal process. Occasional serotonin cells possessed a threadlike basal process with varicos‐ities and a terminal bouton, reminiscent of a neuronal process. Immunoreactivity for chromogranin A, a carrier protein common to endocrine paraneurons, was demonstrated in all of the urethral serotonin cells. The chromogranin A‐immunoreactive granules accumulated more densely in the basal and perinuclear regions of the cell. It is hypothesized that the serotonin‐immu‐nopositive paraneurons may receive chemical and/or physical information from urine and, in response to it, secrete serotonin which presumably causes the contraction of the musculature of the urethra.
An assessment of posture in bipedal rats
Authors: Moravec Steven J. , Cleall John F. 
Published: February 2005

AbstractAlteration in posture was examined following foreleg amputation in rats. After the surgical induction of bipedal stance, a detailed, quantified, and longitudinal assessment of rat posture and the amount of time spent in the upright stance was undertaken.An experimental group of rats had both forelimbs amputated. A group of unaltered quadrupedal rats served as controls. A standardized series of photographs of altered and control rats was taken. Postural differences between the two groups of rats were analyzed through photographic analysis of their profiles in upright and in crouched positions.Analysis of the photographs showed that the percentage of rats assuming upright posture did not differ between the experimental and control groups. Foreleg amputation forced the rats to adopt an altered posture, but did not result in habitual assumption of upright stance to a greater degree than that of controls. Adaptation to bipedalism was marked by a tucking of the hindlimbs under the body, and a flexure of the vertebral column and the head.
Animal model of acute pericarditis and its progression to pericardial fibrosis and adhesions: Ultrastructural studies
Authors: Leak Lee V. , Ferrans Victor J. , Cohen Steven R. , Eidbo Elling E. , Jones Michael 
Published: February 2005

AbstractTo study the evolution of pericardial inflammation, we have developed a model of pericarditis in sheep by surgically injecting heat‐killed staphy‐lococci and Freund's adjuvant into the pericardial cavity under sterile conditions. The pericarditis evolved through the following phases: (1) inflammatory response, (2) mesothelial cell injury and desquamation, and (3) fibrotic phase. At 3–24 hr there was increased microvascular permeability, which resulted in the exudation of fluid, neutrophils, macrophages, ami fibrin into the pericardial cavity and the pericardial intersti‐tium. By 72 hr, large numbers of inflammatory cells were aggregated on the mesothelial surfaces and dispersed throughout the pericardial cavity, either as free‐floating cells or located between strands of fibrin. At 6 days, fibrinolysis was apparent along the mesothelial surfaces; and newly formed collagen fibrils were deposited throughout the interstitial spaces and among the aggregated cells. These fibrils provided a matrix for the growth of new blood and lymphatic vessels into new connective tissue on both parietal and visceral pericardial surfaces. At 2 weeks, intrapericardial fibrosis had produced focal adhesions between the pericardial surfaces. By 1 month, extensive areas of the pericardial cavity were obliterated. By 9 months, there was a marked reduction in the numbers of cells and blood vessels and increased deposition of collagen and elastic fibers. The intrapericardial injection of heat‐killed staphylococci and adjuvant provides a reproducible animal model to study the time course of pericardial inflammation.
On the origin of ganoine: Histological and ultrastructural data on the experimental regeneration of the scales of Calamolchthys calabaricus (osteichthyes, brachyopterygii, polypteridae)
Authors: Sire Y. , Géraudie J. , Meunter F. J. , Zylberberg L. 
Published: February 2005

AbstractIn order to understand the process of anoine formation on the ganoid scales, scale regener‐ation has been studied to overcome the lack of a growth cries of scale ontogeny. Seven stages of ganoid scale regeneration have been defined over a period of five months in the polypterid fish Calamoichthys calabariits. The study has been carried out using transmission electron microscopic techniques. After wound healing and differentiation of the osseous basal plate, a layer of vascular dentin is deposited at the upper surface of he basal plate owing to the presence there of odonto‐ilasts closely applied to the dentin. When these cells nove away, a close contact is then established between he stratified epidermis and the regenerating scale. Nu‐nerous alterations of the epidermal‐dermal boundary occur until its disappearance and a thick layer of pre‐canoine is formed. This layer is progressively mineral‐zed; and finally an organic intermediate layer differentiates between the ganoine, which is a hyper‐nineralized tissue, and the overlying epidermis.This ultrastructural study demonstrates rather un‐quivocally the involvement of the inner epidermal layer (EL) in the appearance and growth of the ganoine. It suggested that these epidennal cells can be compared functionally to the inner dental epithelium (IDE) described during mammal tooth morphogenesis. Consequently, our results allow us to propose that ganoine an be identified as true enamel, although additional lata are necessary to analyze the proteinaceous com‐ponent of its organic matrix.
Spontaneous regeneration of older dystrophic muscle does not reflect its regenerative capacity
Authors: Bourke Dianna L. , Ontell Marcia , Taylor Floyd 
Published: February 2005

AbstractYoung dystrophic (dy) murine muscle is capable of ( spontaneous) regeneration (i.e., regeneration in the absence of external trauma); however, by the time the mice are 8 weeks old, this regeneration ceases. It has been suggested that the cessation of regeneration in dystrophic muscle may be due to exhaustion of the mitotic capability of myosatellite cells during the early stages of the disease. To test this hyptothesis, orthotopic transplantation of bupivacaine treated, whole extensor digitorum longus muscles has been performed on 14 to 16‐week‐old 129 ReJ/++ and 129 ReJ/dydy mice. The grafted dystrophic muscle is able to produce and maintain for 100 days post‐transplantation 356 ± 22 myofibers, a number similar to that found in age‐matched dystrophic muscle. The ability of old dystrophic muscle to regenerate subsequent to extreme trauma indicates that the cessation of ( spontaneous) regeneration is due to factor(s) other than the exhaustion of mitotic capability of myosatellite cells. Moreover, there is no significant difference in myosatellite cell frequencies between grafted normal and dystrophic muscles (100 days post‐transplantation). Myosatellite cell frequencies in grafted muscles are similar to those in age‐matched, untraumatized muscles. While grafting of young dystrophic muscle modifies the phenotypic expression of histopathological changes usually associated with murine dystrophy, grafts of older dystrophic muscle show extensive connective‐tissue infiltration and significantly fewer myofibers than do grafts of age‐matched normal muscle. As early as 14 days post‐transplantation, it is possible to distinguish between grafts of old, normal and dystrophic muscles. It is suggested that the connective tissue stroma, present in the dystrophic muscle at the time of transplantation, may survive the grafting procedure.
Comparison of components of the testis interstitium with testosterone secretion in hamster, rat, and guinea pig testes perfused in vitro
Authors: Mendis‐Handagama S. M. L. C. , Zirkin B. R. , Ewing L. L. 
Published: February 2005

AbstractComponents of the testis and cytoplasmic organelles in Leydig cells were quantified with morphometric techniques in hamster, rat, and guinea pig. Testosterone secretory capacity per gram of testis and per Leydig cell in response to luteinizing hormone (LH) (100 ng/ml) stimulation was determined in these three species from testes perfused in vitro. Numerous correlations were measured among structures, and between structures and testosterone secretion, to provide structural evidence of intratesticular control of Leydig cell function.Testosterone secretion per gm testis and per Leydig cell was significantly different in the three species: highest in the guinea pig, intermediate in the rat, and lowest in the hamster. The volume of seminiferous tubules per gm testis was negatively correlated, and the volumes of interstitium. Leydig cell, and lymphatic space per gm testis were positively correlated with testosterone secretion. No correlations were observed between volumes of blood vessels, elongated spindle‐shaped cells, or macrophages per gm testes and testosterone secretion.The average volume of a Leydig cell and the volume and surface area of smooth endoplasmic reticulum (SER) and peroxisomes per Leydig cell were positively correlated, and the volume of lysosomes and surface area of inner mitochondrial membrane per Leydig cell were negatively correlated with testosterone secretion. No correlations were observed between volume and surface area of rough endoplasmic reticulum (RER), Golgi apparatus, and lipid, and volume of ribosomes, cytoplasmic matrix, and the nucleus with testosterone secretion per Leydig cell.These results suggest that Leydig cell size is more important than number of Leydig cells in explaining the difference in testosterone‐secreting capacity among the three species, and that this increase in average volume of Leydig cell is associated specifically with increased volume and surface are of SER and peroxisomes. An important unresolved question is what is the role of peroxisomes in Leydig cell steroidogenesis.
Amianthoid (Asbestoid) transformation: Electron microscopical studies on aging human costal cartilage
Authors: Mallinger R. , Stockinger L. 
Published: February 2005

AbstractThe present study reports on the fine structure of human costal cartilage at different ages in order to obtain information on the morphogenesis of amianthoid fibers. Our results reveal an overall increase of collagen fibril diameter with increasing age, even in areas with no signs of amianthoid transformation. Ultrastmctural evidence is presented that this increase in diameter is due to a gathering of the preexisting collagen fibrils. The age‐related change in collagen fibril diameter is paralleled by changes in the composition and ultrastructural appearance of cartilage proteoglycans (as revealed by acridine orange staining). Acridine‐orange‐positive filaments indicative for proteoglycans are markedly reduced in size with advancing age in centrally located regions of costal cartilage. Treatment with testicular hyaluronidase previous to acridine‐orange staining leaves these small proteoglycan filaments unaffected. By contrast, the filaments visible after acridine‐orange staining in the extracellular matrix near to the perichondrium are susceptible to hyaluronidase treatment. Infrequently, a sharp increase in collagen fibril diameter can be observed in territorial matrix areas of degenerating chondrocytes. This observation is conspicuous at ages of 10 and 20 years. Amianthoid transformation is characterized by the appearance of collagen fibrils strictly arranged in parallel. These amianthoid fibers are embedded in a matrix rich in small acridine‐orange‐positive filaments similar to the proteoglycan filaments observed in centrally located matrix regions. It can be concluded that extensive remodelling not only of the collagen fibrils but also of the cartilage proteoglycans is involved in the development of amianthoid transformation.
Developmental heterogeneity of mesenchymal glycosaminoglycans (GAG) distribution in chick embryo lung anlagen
Authors: Becchetti E. , Evangelisti Rita , Stabellini G. , Pagliarini A. , Borrello Elia Del , Calastrini Carla , Carinci P. 
Published: February 2005

AbstractThe presence and distribution of mesenchymal components in the extracellular matrix during lung development in the chick embryo (from 5½/6 to 18 incubation days) has been examined histochemically. Attention is focused mainly on glycosaminoglycans (GAG). Morphological reconstructions show three main stages: first (5½/6–8 days), formation of 2nd‐order branching; second (9–12 days), proliferation of para‐bronchi and third (from 13th day on), formation of air capillaries. In the first phase, hyaluronic acid (HA) prevails around the mesobronchus, but chondroitin sulfate (CS) dominates the 2nd‐order branches. Basement membranes of 2nd‐order branches are strongly positive for sulphated GAG. In the second phase, CSA increases in the ground substance of mesenchyme. This increase is irregular, being smaller in older areas (mesobronchus, branches of 2nd order) and larger in the more recent parabronchi, which extend into the lateral and dorsal areas of the rudiment. An increase in both sulfated GAG and glycoprotein (GP) occurs in basement membranes. In the third phase, GAGs are uniformly distributed in the mesenchymal septa and around the interlobular vascular network. This concentration decreases while the GP concentration increases. Basement membranes around every branch of the 1st, 2nd, and 3rd orders possess large quantities of GP. Mesenchymal GAG occurs in every stage of lung development, temporally correlating with the morphogenesis and differentiation of epithelium. Our results provide necessary information, which has not been available so far. Experimental studies specifically designed to clarify the developmental significance of such a heterogeneous distribution may be interpreted in the light of this information.
Maturation antigen of the mouse sperm flagellum. I. Analysis of its secretion, association with sperm, and function
Authors: Feuchter F. A. , Tabet A. J. , Green M. F. 
Published: February 2005

AbstractWe report here recent findings on the sperm maturation antigen SMA4, which is secreted by holocrine cells of the distal caput epididymis and binds to the flagellar surface of mouse sperm during epididymal transit.Washed sperm from the caput and corpus epididymides of mice were examined by immunofluorescence and SDS‐PAGE using wheat germ agglutinin, which binds specifically to SMA4 as a primary probe. Results indicate that sperm first exhibit WGA reactivity on their flagellae in the region of the distal caput, and that the appearance of WGA receptors is due to the binding of a 54‐Kd glycoprotein (SMA4) to the cell surface. Extracts of epididymis containing SMA4 were tested for their ability to bind to the surfaces of caput and corpus sperm. Caput sperm surfaces bound SMA4 in & temperature‐independent manner, and binding occurred in the presence of enzyme inhibitors., suggesting a nonenzymatic process. Biochemical studies revealed that SMA4 contains disulfide bonds which stabilize it on the sperm surface and restrict its mobility. Terminal carbohydrate residues of the molecule are sialic acids. The addition of SMA4 to caput sperm flagellae prevented tail‐to‐tail agglutination, normally seen when caput sperm are diluted into saline; and SMA4 was able to disperse clumps of agglutinated caput sperm. The data suggest that a primary function of SMA4 is to prevent tail‐to‐tail agglutination of sperm during storage in the epididymis.
The development of the sexually indifferent gonad in the prosimian, Galago crassicaudatus crassicaudatus
Authors: Yoshinaga Kazuya , Hess David L. , Hendrickx Andrew G. , Zamboni Luciano 
Published: February 2005

AbstractThe morphogenesis of the sexually indifferent gonad of the primate Galago crassicaudatus crassicaudatus was studied by high‐resolution light microscopy and electron microscopy in 15 embryos aged 26 to 33 days. Onset of gonadal development follows the morphogenesis of the mesonephros by a conspicuous interval and is identified as the time when the first primordial germinal cells arrive in the region ventral to the central third of the mesonephros; this is followed by intense proliferation of the coelomic mesothelial cells lining the area. They become organized into short piles that deepen in the underlying mesenchyme, enclosing the germinal cells in the process. Rapidly, the piles become confluent forming a compact mass, the gonadal blastema, which is soon cleaved into gonadal cords by stroma and vascular lacunae. The mesonephros becomes involved in the morphogenesis of the gonad only in late stages of development when anatomic continuities become established between the capsules of its regressing glomeruli and the elongating gonadal rete cords. These observations show that in the Galago the somatic cells of the gonadal blastema, i.e., the precursors of the definitive testicular and ovarian sustentacular cells, derive from the coelomic mesothelium in contrast to other mammals, e.g., ruminants and rodents, where they are of mesonephric derivation. This important point is discussed in light of the differences that exist among species with regard to the structural complexity, functionality, and stages of differentiation/ involution of their mesonephroi on the one hand, and the time of gonadal development on the other.
Ultrastructural cytochemistry of complex carbohydrates in developing feline neutrophils
Authors: Fittschen C. , Parmley R. T. , Austin R. L. 
Published: February 2005

AbstractThe feline species provides animal models for at least six congenital lysosomal disorders. Since knowledge of normal feline neutrophils is a prerequisite for studies of their abnormalities, the present report describes the morphology and cytochemistry of normal feline neutrophils and compares the subcellular distribution of sulfate‐ and vicinal‐glycol‐containing complex carbohydrates to that of peroxidase and acid phosphatase. Immature feline primary granules, formed in promyelocytes, were stained for peroxidase, acid phosphatase, sulfate, and vicinal glycols. During maturation, primary granules retained strong staining for peroxidase, but staining for vicinal glycols decreased, and acid phosphatase and sulfate reactivity was lost. Secondary granules formed in myelocytes lacked peroxidase, acid phosphatase, and sulfate staining, but stained intensely for vicinal‐glycol‐containing complex carbohydrates. No analogues of tertiary granules previously described in rabbits and humans were demonstrated in feline neutrophils. However, a new sequential staining technique for peroxidase and vicinal glycols has suggested the formation in myelocytes and late neutrophils of a third granule type that contained peroxidase, acid phosphatase, and vicinal glycols but lacked sulfate staining. Thus, the staining characteristics of primary and secondary granules in cats closely resembled those in humans and rabbits. The third (late‐forming) type of granule has not previously been described in other species.
Ultrastructure of the pineal body of the common vampire bat, Desmodus rotundus
Authors: Bhatnagar Kunwar P. 
Published: February 2005

AbstractThe type AB pineal body of the common vampire bat, Desmodus rotundus was recessed and lobulated, was extensively vascularized and intimately related to great veins, and was unassociated with the epithalamic region. The habenular and the posterior commmissures coursed anteriorly and were unassociated with the pineal. The saccular suprapineal recess of the third ventricle extended dorsally juxtaposed to the pineal body. These anatomical features are likely to make pinealectomies in the vampire more difficult to manage.The pineal parenchyma consisted of light pinealocytes surrounded by canaliculi of various sizes, often transmitting unmyelinated nerve fibers and glial processes. Desmosomes were common. The pinealocyte nuclei were large and highly infolded; characteristic cytoplasmic constituents included abundant dilated Golgi complexes associated with clear vesicles, numerous polyribosomes, few single cisternae of ribosome‐studded rough endoplasmic reticulum, mitochondria, and occasional multivesicular bodies and lysosomes. Almost all pinealocytes exhibited centrioles and some, in addition, displayed basal bodies but rarely ciliary shafts. A conspicuous feature of the pinealocyte cytoplasm was the presence of branched bundles of intermediate filaments, especially in the perinuclear zone.Siderotic macrophages, lipofuscin‐pigment‐containing phagocytic cells, mast cells, myelin bodies, and both fenestrated and continuous capillaries were present. The perivascular compartment was densely packed with unmyelinated nerve bundles containing small to large fibers exhibiting axoaxonic densities. Other constituents of the perivascular compartment were club‐shaped pinealocyte processes filled with clear vesicles, microtubules, an occasional mitochondrion, glial processes, and collagen fibers. “Synapselike” contacts were observed between the axons and pinealocyte processes. Abundant pinocytotic vesicles in the capillary endothelium indicated active pinocytosis. Myelinated nerve fibers were lacking. The pineal ultrastructure of Desmodus is in part unlike that reported for other mammals, including bats.
Gross and cellular analysis of 6‐mercaptopurine‐induced cleft palate in hamster
Authors: Burdett David N. , Shah Ravindra M. 
Published: February 2005

AbstractThe present study analyzes the morphological, histochemical, and ultrastructural aspects of the pathogenesis of 6‐mercaptopurine (6MP)‐induced cleft palate in hamster fetuses. Gross and light microscopic observations indicated that 6MP stunts the growth of vertical palatal shelves and thus induces cleft palate. Ultrastructural analysis showed that, in contrast to controls, 6MP‐induced alterations were first seen in the mesenchymal cells 24 hr after drug administration. The initial alterations were characterized by swelling of the nuclear membrane. During the next 12 hr, lysosomes were seen first in the mesenchymal cells and then in the cells of the medial edge epithelium (MEE) of the developing palatal primordia. The appearance of lysosomes was temporally abnormal and was interpreted as a sublethal response to 6MP treatment. Subsequently, the nuclear alterations and the lysosomes diminished; and 48 hr after 6MP administration, they were absent from the palatal tissues. Ninety hours after 6MP administration, unlike the controls (in which the palatal shelves were already fused), changes were seen at the epithelial‐mesenchymal interface in the developing cleft palatal shelves. These changes were characterized by breakdown of the basal lamina and epithelial‐mesenchymal contacts. Eventually, at term, the MEE of the vertical shelf stratified. It was suggested that 6MP affected cytodifferentiation in the palatal tissues during the critical phase of early vertical shelf development and thereby induced cleft palate.