bluuebunny/crossref_metadata_2025 huggingface dataset:
SEM of capillary pericytes prepared by ultrasonic microdissection: Evidence for the existence of a pericapillary syncytium
Authors: Wagner Roger C. , Hossler Fred E.
Published: February 2005

Retia mirabile of the eel swimbladder were exsanguinated, perfusion‐fixed and subjected to prolonged osmication. They were then microdissected by ultrasonication which delaminated the capillary bed along planes which revealed the surfaces of arterial and venous capillaries. This procedure resulted in cleaned capillary surfaces largely free of connective tissue elements and basement membrane material. The arterial capillary segments were heavily invested with pericytes characterized by plump cell bodies containing nuclei and an extensive system of processes encircling the capillary wall. These processes exhibited a hierarchical organization consisting of primary, secondary, and tertiary elements arising roughly at right angles to each other. Primary and secondary processes exhibited frequent anastomoses and resulted in cytoplasmic continuity between adjacent cell bodies. Processes were also observed to form connections between pericytes on adjacent capillaries. These observations are evidence for the existence of a pericapillary syncytium in which cell bodies may be connected in series and in parallel throughout the arterial capillary bed. This syncytial organization would provide for a coordinated and global contractile response of pericytes to vasoactive hormones and other effectors. It may also provide for synchrony of nuclear division during developmental spread of pericytes along capillary surfaces.© Willey‐Liss, Inc.
Evidence for the glyoxyiate cycle in human liver
Authors: Davis Walter L. , Goodman David B. P.
Published: February 2005

The enzymatic activities unique to the glyoxylate cycle of higher plants and certain lower invertebrates, isocitrate lyase and malate synthase, have been demonstrated in homogenates prepared from human liver. Human liver can also carry out cyanide‐insensitive fatty acid oxidation from palmitate. Utilizing light microscopic immunocytochemistry with an antibody produced against Euglena malate synthase, this enzyme localizes in numerous ovoid granules in human hepatocytes. Also, immunocytochemistry using antibodies produced against rat fatty acyl‐CoA oxidase showed that this enzyme was localized in similar structures. With routine cytochemistry, catalase was seen in identical granular bodies. Both catalase and fatty acyl‐CoA oxidase are peroxisomal enzymes. The presence of malate synthase in liver homogenates was further confirmed by Western blot analysis. These data suggest that the human liver may be capable of utilizing the carbon backbone of fatty acids for carbohydrate synthesis since the glyoxylate cycle in lower organisms subserves this anabolic function.© Willey‐Liss, Inc.
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

The 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

The 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

Size, 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

The 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

Since 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

During 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

A 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

The 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

The 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

The 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

This 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

Attempts 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

The 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

To 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.
Proliferative responses of endothelial cell populations to experimentally induced inflammatory lesions of gingival connective tissues in the cynomolgus monkey (Macaca fascicularis)
Authors: Nemeth E. , Kulkarni G. V. , McCulloch C. A. G.
Published: February 2005

Background: Endothelial cells exhibit heterogeneous and tissue‐selective responses to injury and inflammation. The regulation of the size of endothelial populations in specific tissue sites is poorly characterized, particularly in soft connective tissues adjaceent to bone. To investigate the effect of a primarily lymphocytic infiltrate on endothelial cell proliferation and growth of blood vessels, a primate model was used that reliably exhibits localized, distinct inflammatory, and destructive lesions in isolated sites of mucosal connective tissues adjacent to bone and epithelium around teeth. Methods: Three Cynomolgus monkeys with healthy periodontium and two with spontaneously occurring inflammation or induced connective tissue destruction were pulse labeled with 3H‐thymidine. Morphometric analyses of radioautographs from mid‐sagittal supra‐alveolar gingival connective tissues of incisor teeth were performed in sites subjacent to junctional, sulcular, and oral epithelium, in the body of the lamina propria and just superior to the alveolar bone crest. Results: Subjacent to the sulcular epithelium there was a statistically significant (P < 0.01) increase in lymphocyte density between health and inflammation. The percentage of endothelial cells incorporating 3H‐thymidine label (LI) and the number of blood vessels per unit area were significantly increased in this same site in inflamed samples (P < 0.02) but were not elevated further in lesions in which there was destruction of soft connective tissues. However, there was no increase of the numbers of the cross‐sectional areas of blood vessels between samples of inflamed and destroyed tissues. Conclusions: (1) Experimentally induced inflammation and connective tissue destruction in the gingival connective tissues of Cynomolgus monkeys is associated with site‐specific perturbations in the turnover of endothelial cells that is closely linked to lymphocytic infiltration; (2) the vascular response is a generalized increase in endothelial cell proliferation and blood vessel numbers but not lumen size or number of endothelial cells, suggesting the existence of homeostatic controls for preservation of the whole population in a steady state. © 1994 Wiley‐Liss, Inc.
Occurrence and localization of calbindin‐D28kin kidney and cerebellum of the slider turtle,Trachemys scripta
Authors: Mutema George K. , Rhoten William B.
Published: February 2005

Backgrouns: Since its initial discovery in the avian intestine, calbindin‐D28khas been reported to occur in various species and tissues. Although calbindin‐D28kbinds calcium ions in the physiologically relevant range of intracellular calcium, its functional role in the various cell types where it has been localized remains unknown.

Methods: We examined the occurrence of calbindin‐D28kin the brain and kidney of the testudine reptile,Trachemys scripta, by immunoblotting and immunocytochemistry using rabbit anti‐sera directed against rat renal calbindin‐D28kand chicken intestinal calbindin‐D28k.

Results: Immunoblotting revealed the presence of calbindin‐D28kin the turtle tissues. A single immunoreactive band in the 28,000 relative molecular mass region was visualized in cerebellar and renal homogenates. Immunocytochemistry revealed reaction product for the presence of calbindin‐D28kin the Purkinje cells of the cerebellum, and in the distal tubular cells of the nephron. Processes as well as the perikaryon of the Purkinje cell were immunoreactive.

Conclusion: This study describes the occurrence and cellular localization of calbindin‐D28kin a reptilian cerebellum, and confirms the phylogenetic distribution of renal calbindin‐D28kto the oldest major reptilian group. © 1994 Wiley‐Liss, Inc.
Microangioarchitecture of the guinea pig common bile duct and duodenal papilla: A scanning electron and light microscopic study
Authors: Aharinejad S. , Lametschwandtner A. , Böck P. , Firbas W.
Published: February 2005

Background: The microvascular pattern of the duodenal papilla is unknown. Since the duodenal papilla is located in the transition zone between the stomach and duodenum, and because it regulates bile transfer into the duodenum, a particular microangioarchitecture can be expected. Therefore, we examined the microvasculature of the papilla using guinea pigs as a model.

Methods: The microvascularization of the duodenal papilla and common bile duct was studied in 26 adult guinea pigs (Cavia porcellus), using scanning electron microscopy of microvascular corrosion casts and critical point dried specimens, and light microscopy of tissue sections.

Results: The duodenal papilla is located in the cranial portion of the duodenum, approximately 5 mm beyond the pyloric valve. At the most luminal aspect of the cast papilla, ring‐shaped capillaries, resembling those of the cast gastric mucosa, are present. Deeper parts of the papilla are provided with villi. Subepithelial capillaries of the papilla are 15 μm thick in average. These capillaries have a dual blood supply either via the straight long arterioles arising from the submucosa or by the pericryptal capillaries. The common bile duct comprises numerous mucoid glands with their pits surrounded by ring‐shaped capillaries in corresponding casts.

Conclusions: The special arrangement of different capillary patterns, together with their luminal size and the dual blood supply, favor their protective role from the gastric chyme. © 1994 Wiley‐Liss, Inc.
Analysis of a tension/compression skeletal system: Possible strain‐specific differences in the hierarchical organization of bone
Authors: Skedros John G. , Bloebaum Roy D. , Mason Mark W. , Bramble Dennis M.
Published: February 2005

Background: Examination of a simple skeletal cantilevered beam‐like bone (artiodactyl calcaneus) suggests that regional differences in strain magnitude and mode (tension vs. compression) reflect regional adaptation in the structural/material organization of bone. The artiodactyl (e.g., sheep and deer) calcaneus has a predominant loading condition typified by the unambiguous presence of prevailing compressive and tensile strains on opposite cortices. Bone habitually loaded in bending may accommodate regional disparities in loading conditions through modifications of various aspects of its organization. These include overall bone build (gross size and shape), cross‐sectional shape, cortical thickness, and mineral content.

Methods & Results: Cross‐sections taken along the calcaneal body exhibited cranial‐caudal elongation with the compression (cranial) cortex thicker than the tension cortex (P < 0.01). Mineral content (ash fraction) was significantly greater in the compression cortex (P < 0.01), averaging 6.6% greater than in the tension cortex. Strong positive correlations were found between mineral content and section location in both the tension (r2 = 0.955) and compression (r2 = 0.812) cortices. These correlations may reflect functional adaptations to the linear increases in stress that are known to occur in the distal‐to‐proximal direction in simple, unidirectionally loaded cantilevered beams. According to engineering principles, the roughly triangular transverse cross‐sectional geometries and thicker compression cortex are features consistent with a short cantilevered structure designed to resist unidirectional bending.

Conclusions: Known differences in mechanical properties of bone in tension vs. compression suggest that these regional differences in cortical thickness and mineralization may be related to differences in strain mode. These structural/material dissimilarities, however, may be related to regional variations in strain magnitude, since bending and axially directed stresses in a simple cantilevered structure produce greater strain magnitudes in the compression domain. It is possible that the superimposed habitual strain magnitudes enhance strain‐mode‐specific adaptive responses. We hypothesize that these structural/material differences reflect the capacity of bone to process local information and produce a regionally heterogeneous organization that is appropriate for prevailing loading conditions. © 1994 Wiley‐Liss, Inc.

This article is a US Government work and, as such, is in the public dotmain in the United states of America

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Ultrastructure of nonspecific cytotoxic cells in teleosts. I. Effector‐target cell binding in a marine and a freshwater species (Seabream: Sparus aurata L., and Carp: Cyprinus carpio L.)
Authors: Meseguer Jose , Esteban M. Angeles , Lopez‐ruiz Antonio , Bielek Edith
Published: February 2005

Background: Fish cytotoxic effectors form a cell population whose ultrastructure and properties of conjugation with target cells have not been completely established. We report the ultrastructure of the non‐specific cytotoxic cells in a seawater teleost (Sparus aurata L.) and compare it to a freshwater species (Cyprinus carpio L.).

Methods: Blood leucocytes were incubated with HeLa or B16 melanoma cells. Samples were processed for transmission electron microscopic study.

Results: Conjugates consisting of leucocytes binding targets were regularly observed after 30 min, 1 hr, or 2 hr of incubation. In both species leucocytes binding to targets showed ultrastructural features of either monocyte‐like or lymphocyte‐like cells. Monocyte‐like cells usually appeared flattened against the targets and seemed to enclose fragments of the target to form cytoplasmic vesicles and the content of their scarce cytoplasmic granules seemed to be delivered into these vesicles. In the seabream lymphocyte‐like cells, dense cytoplasmic granules occurred only occasionally, and neither microvilli nor cell processes were present at the contact areas with the targets. In the carp, the contacts were more numerous and formed regularly interdigitating contact areas and the lymphocytes showed granules with characteristic dense and fibrillar contents.

Conclusions: We conclude that seabream and carp have a leucocyte cell population with ultrastructural features of either monocytes or lymphocytes showing nonspecific cytotoxic ability. © 1994 Wiley‐Liss, Inc.
Regional variations in the ultrastructural features of secretory cells in the rat oviductal epithelium
Authors: Abe Hiroyuki
Published: February 2005

Background: In mammals, the oviductal secretory cells and their secretions play important roles in reproductive and developmental events. Therefore, many electron microscopic studies of mammalian oviductal epithelial cells have been performed.

Methods: The secretory cells in various regions of the rat oviduct during the estrous cycle were examined by transmission electron microscopy.

Results: In the fimbriae, the secretory cells contained small secretory granules with moderately electron‐dense matrices and many large bodies that resembled lipid droplets. In the ampullar cells, small secretory granules with moderately electron‐dense matrices were observed in the apical cytoplasm. In the isthmus, the secretory cells contained numerous secretory granules with moderately electron‐dense matrices. Electron‐dense areas were frequently observed in many of the granules of the isthmic cells. Vesicles, partially filled with a dense substance, frequently were observed in the isthmic cells and occasionally in the ampullar cells. Very long stereocilia projected from the surfaces of the isthmic secretory cells into the lumen. Exocytosis of the secretory granules was observed. In addition, there was evidence to suggest the release of the bodies that resembled lipid droplet occurred. Cysts and ciliated vacuoles that appeared to be intraepithelial were frequently observed in the fimbrial and ampullar epithelia. No dramatic changes in the relative numbers of ciliated and secretory cells in any oviductal segment were observed during the estrous cycle.

Conclusions: Our ultrastructural observations of the rat oviduct revealed marked regional variations in the morphological features of secretory cells. These results may provide insight into regional and cellular differences in the function of the rat oviduct. © 1994 Wiley‐Liss, Inc.
Developmental expression of immobilin in the rat epididymis
Authors: Hermo L. , Barin K. , Oko R.
Published: February 2005

Background: Immobilin is a protein secreted by principal cells of the distal initial segment, intermediate zone and caput epididymidis of adult rats, which serves to immobilize spermatozoa. In the distal cauda, epithelial clear cells are involved in its endocytosis. The objective of this study was to correlate the developmental events in the maturation of the epdidymis with the timing of immobilin secretion and endocytosis in order to evaluate the testicular or epididymal factors which may influence or regulate immobilin expression.

Methods: Our approach was to follow and compare the developmental expression of immobilin by light microscope immunocytochemistry in control and efferent duct ligated rats of different postnatal ages.

Results: Coincident with the morphological maturation of the principal cells by postnatal day 39, immobilin displayed the characteristic secretory immunostaining pattern found in adults. This adult‐like expression occurred despite the absence of spermatozoa in the lumen but was coincident with high levels of circulating and luminal androgens. In contrast, immobilin secretion in rats whose efferent ducts were ligated at day 15 was weak to non‐existent in the principal cells of the caput epididymidis at day 28 and remained so into adulthood, indicating that principal cells of this region of the epididymis are dependent either directly or indirectly upon testicular factors present in the lumen for immobilin expression. However, secretion of immobilin in the principal cells of the distal initial segment was unaffected by ligation and unlike the case in control rats high levels of immobilin also continued to be secreted into adulthood by the principal cells of the proximal initial segment. Thus in the distal initial segment immobilin secretion is not regulated by luminal factors originating from the testis, while in the proximal initial segment the normal suppression of immobilin that occurs by postnatal day 39 is. Despite ligation, endocytosis of immobilin by clear cells of the distal cauda epididymidis occurred by day 49, indicating that luminal testicular factors are not essential for stimulating the uptake of immobilin by these cells.

Conclusions: The results taken together suggest that there are stimulatory and inhibitory luminal testicular factors involved in the regional development of immobilin secretion in the epididymis. There are also immobilin secreting regions in the epididymis, whose secretory development is independent of luminal testicular factors. © 1994 Wiley‐Liss, Inc.
Ultrastructural differentiation of the first hensen cell in the gerbil cochlea as a distinct cell type
Authors: Spicer Samuel S. , Schulte Bradley A.
Published: February 2005

Background: The mammalian cochlea contains beneath and lateral to outer hair cells, several types of supporting cells. The function of these cells has not been explained beyond providing a structural base.

Methods: The supporting cells of gerbil cochlea were examined by electron microscopy with a view to elucidating their biologic activity on the basis of cytologic structure.

Results: Ultrastructural examination differentiated the laterally located Hensen cells from their medial neighbor connected to the third Deiters cell. The later cell formed a cover to the outer tunnel between Hensen and Deiters cells, appeared not to reach the basilar membrane, and exhibited a denser cytosol and more mitochondria, compared to Hensen cells. In these respects the cell observed here to cover the outer tunnel, corresponded with the tectal cell described by Henson et al. (1983) in the mustache bat, but not heretofore documented in other animals.

Conclusions: This distinctive cell in the gerbil differend in displaying unique villus‐like structures which projected from the basomedial surface and are referred to as fimbriae. The fimbriae and interspersed filopodia largely filled outer tunnel space and expanded the cell's basal surface. The amplification of basal plasmalemma by fimbriae and their content of mitochondria testify to a role for the tectal cell in ion resorption and an influence on ion content and volume of outer tunnel fluid. © 1994 Wiley‐Liss, Inc.
Cartilago cordis in serpents
Authors: Young Bruce A.
Published: February 2005

Background: The cartilago cordis, a cartilaginous element present within the heart, has been found in a number of vertebrates. The present study provides a detailed description and comparative analysis of the cartilago cordis in snakes.

Methods:Transverse sections through the hearts of 42 snakes and three monitor lizards were examined.

Results: A cartilago cordis was found near the roots of the aortic trunk and pulmonary artery in eleven species of snakes. There is substantial variation in the size, shape, and precise location of the cartilago cordis.

Conclusions: The presence of a cartilago cordis does not correlate with body size, taxonomic relationships, or habitat preference. The cartilago cordis may simply represent an illustration of the potential for chondrification that is present in the connective tissue of the aorticopulmonary septum. © 1994 Wiley‐Liss, Inc.
Hamster supraoptic nucleus: Cytoarchitectural, Morphometric, and three‐dimensional reconstruction
Authors: Navarro Ana , Tolivia Jorge , Alvarez‐Uría Manuel
Published: February 2005

Background: The present paper describes the cytoarchitectonic, morphometric, and three‐dimensional characteristics of the golden hamster supraoptic nucleus (SON) in order to provide an anatomical basis for subsequent morphofunctional studies that use this species as an experimental animal. The dimensions (volume and length) and the number of cells of each part of the supraoptic nucleus were obtained, as well as morphometric parameters of their neurons (cross‐sectional area and maximum and minimum diameters). A three‐dimensional reconstruction of hamster SON has been made in order to know the spatial morphology of this nucleus and to reveal the structural differences between both parts.

Methods: Ten male adult golden hamsters (Mesocricetus auratus) were used. Animals were anaesthetized and transcardially perfused with 4% paraformaldehyde in 0.1 M phosphate buffer at pH 7.2. The hypothalamic area from seven animals was dissected out, dehydrated, and embedded in paraffin. Serial sections of 10 μm were cut in a coronal plane. Sections were stained with thionin, dehydrated, cleared in eucalyptol, and mounted with Eukitt. To prove the neurosecretory nature to the SON, every fourth section was immunostained against neurophysin by using the peroxidase‐antiper‐oxidase method. To study the neuronal morphometric parameters, all magnocellular neurons of the SON were drawn in sections separated 80 μm with the aid of a camera lucida under 500× magnification. Serial 50 μm thick frozen sections of the hypothalamus from three animals were drawn with camera lucida to determine the volume of the two parts of the SON and to make the three‐dimensional reconstruction.

Results: The SON extends rostrocaudally 1.98 ± 0.03 mm from the preoptic area to the tuberal hypothalamic area. Two classical parts can be clearly delimited: principal (SONp) and retrochiasmatic (SONr). The neuronal population of the two parts of the SON appears constituted only by magnocellular neurons. The volume of the SONp is 0.039 ± 0.03 mm3 and contains about 762 ± 93 magnocellular cells with a density of 19,151.8 cells/mm3. The volume of the SONr is 0.126 ± 0.03 mm3 and contains about 1,296 ± 132 neurons with a density of 10,536.6 cells/mm3. The three‐dimensional reconstruction reveals that the SONp appears located in a more cephalic, lateral, and dorsal position than the SONr, and a clear discontinuity between the two parts is observed.

Conclusions: The present study shows that the classically termed SON, in the hamster, clearly consists of two spatially separated neural populations. The SONr is longer than SONp and has the larger volume and higher number of neurons; however, the neurons of the SONr are smaller in cell area than those of the SONp. © 1994 Wiley‐Liss, Inc.
Statistical analysis of compositional data in anatomy
Authors: Howel Denise
Published: February 2005

Background: Variables which describe the composition, or relative size of components, of an organism need to be analysed in an appropriate manner.

Methods: A few of the appropriate descriptive and inferential techniques have been described and applied to a number of anatomical data sets.

Results: When applied to data on the composition of the vastus medialis in adults, a small but significant difference in average muscle fibre type distribution was demonstrated between males and females. There was little evidence for a relationship between fibre type distribution and age over the range considered.

Conclusions: Graphical displays via ternary diagrams are a simple way of illustrating compositional data simultaneously between and within groups. Numerical analysis is likely to involve transformation of original variables before standard univariate or multivariate statistical techniques can be used. © 1994 Wiley‐Liss, Inc.