bluuebunny/crossref_metadata_2025_split huggingface dataset:
An immunohistochemical approach to the intrafusal fibers of extraocular muscle spindles in sheep, cow, and pig
Authors: Scapolo P. A. , Costerbosa G. Lalatta , Barazzoni A. M. , Lucchi M. L. , Bortolami R. 
Published: February 2005

AbstractIntrafusal muscle fibers of the extraocular muscles (EOMs) of the sheep, cow, and pig were studied histochemically and immunohistochemically. In sheep and cow spindles, three intrafusal fiber types, namely the bag1, bag2, and chain fibers, were identified by a combination of standard histochemical methods and immunohistochemical staining with antibodies selective for slow‐tonic (antitonic ALD) and slow twitch (anti‐I BA‐D5) myosin. The bag1 and bag2 fibers appeared immunologically different on the basis of their differential reactivity with the two antisera. Anti‐tonic ALD preferentially stained the bag1 fibers, whereas anti‐I BA‐D5 labeled the bag2 fibers. Chain fibers did not react with either antisera. In the pig EOM spindles, in general, one bag and some chain intrafusal fibers were identified. The bag fiber was labeled by anti‐tonic ALD, but it did not react with the anti‐I BA‐D5. These findings point to the existence in pig EOM spindles of only one bag fiber antigenically similar to the bag1 fiber of the other species examined.
Ultrasound investigation of fetal human upper respiratory anatomy
Authors: Wolfson Victoria P. , Laitman Jeffrey T. 
Published: February 2005

AbstractAlthough the human upper respiratory—upper digestive tract is an area of vital importance, relatively little is known about either the structural or functional changes that occur in the region during the fetal period. While investigations in our laboratory have begun to chart these changes through the use of postmortem materials, in vivo studies have been rarely attempted. This study combines ultrasonography with new applications of video editing to examine aspects of prenatal upper respiratory development.Structures of the fetal upper respiratory—digestive tract and their movements were studied through the use of ultrasonography, and detailed frame‐by‐frame analysis. Twenty‐five living fetuses, aged 18–36 weeks gestation, were studied in utero during routine diagnostic ultrasound examination. These real‐time linear array sonograms were videotaped during each study. Videotapes were next analyzed for anatomical structures and movement patterns, played back through the ultrasound machine in normal speed, and then examined with a frame‐by‐frame video editor (FFVE) to identify structures and movements. Still images were photographed directly from the video monitor using a 35 mm camera.Results show that upper respiratory and digestive structures, as well as their movements, could be seen clearly during normal speed and repeat fram‐by‐frame analysis. Major structures that could be identified in the majority of subjects included trachea in 20 of 25 fetuses (80%); larynx, 76%; pharynx, 76%. Smaller structures were more variable, but were nevertheless observed on both sagittal and coronal section: piriform sinuses, 76%; thyroid cartilage, 36%; cricoid cartilage, 32%; and epiglottis, 16%. Movements of structures could also be seen and were those typically observed in connection with swallowing: fluttering tongue movements, changes in pharyngeal shape, and passage of a bolus via the piriform sinuses to esophagus. Fetal swallows had minimal laryngeal motion. This study represents the first time that the appearance of upper airway and digestive tract structures have been quantified in conjunction with their movemements in the living fetus.
Electron microscopic evaluation of the occurrence of matrix vesicles in cartilage
Authors: Mitchell Nelson S. , Shepard Nora L. 
Published: February 2005

AbstractTroubled by variations in the descriptions of shape, appearance, and content of matrix vesicles and the conflicting reports of increased numbers of vesicles in the mineralizing regions of the growth plate contrasted with larger numbers in the resting zone, we embarked on a review of matrix vesicles in the growth plate using a comparison of different fixation techniques. We found matrix vesicles resembling cell debris at all levels of the growth plate, with no particular association with mineral. Lipid bodies surrounded by a membrane of proteoglycan have also been seen in large numbers. The cell debris–like matrix vesicles have been the common finding in reports of digested centrifuged cartilage and may represent cytoplasmic processes. Lipid bodies surrounded by proteoglycan may be similar to the membrane‐bound vesicle described by Ali (Fed. Proc., 35:135–142, 1987) and by Bonucci (Clin. Orthod., 78:108–133, 1971).
Patterns of cell movement in early organ primordia of the chick embryo
Authors: Robert Hilfer S. , Marrero Leslie , Sheffield Joel B. 
Published: February 2005

AbstractPurse‐string constriction of the cytoskeleton at cell poles is generally accepted as the causal mechanism for invagination during early stages of organ formation. However, it is known that other cell movements, including intercalation, play a role in the organotypic shape changes that occur during gastrulation and neurulation. Such cell movements have not been investigated in pouching and branching epithelial primordia. There is reason to suspect that cells within these organ primordia might exchange their neighbors for others, that is, intercalate or translocate, at sites of sharp folding such as borders with the surrounding epithelial sheet or where a bend occurs within the primordium. The greatest difficulty in identifying these movements has been the need to use intact embryos so that the processes are not distorted. This study explores the possibility of using time‐lapse video recording to identify cell movement at these locations. Three organ primordia were tested: otic and thyroid placodes, which had not been tested previously, and neural plate as a control, where movements of this sort have been documented. Embryos or parts containing the primordia were immobilized and cell apices visualized with Hoffman modulation contrast optics. Recordings to an optical memory disc recorder were transferred to a microcomputer for image analysis. The viewing procedure allows reasonably clear visualization of cell apices, and image analysis permits tracking of a number of adjacent cell apices over an extended time period. Several types of movement were found to occur within cell sheets, and the relative abundance of each type depends on the specific primordium. In the neural plate, some cells move many cell diameters from their neighbors. In the other two primordia, most cells show limited shifts in position relative to their neighbors except at regions where folds are formed. In other regions, adjacent cells move as a unit. Knowledge of the movements which occur in any particular primordium is essential to an understanding of the mechanisms controlling its formation.
Glycoconjugate expression of cells of human anagen hair follicles during keratinization
Authors: Ohno Jun , Fukuyama Kimie , Epstein William L. 
Published: February 2005

AbstractChanges in the expression of glycoconjugates in cells of the inner root sheath (IRS) and outer root sheath (ORS) of human anagen hair follicles were investigated by lectin histochemistry. Concanavalin A (Con A) and Ricinus communis (RCA‐I) stained hair follicle cells regardless of their differentiation stages. In IRS, Ulex europeaus‐I (UEA‐I) bound to the surface of the cells as soon as they were morphologically defined, and Glycine max (SBA) stained as their differentiation progressed. Innermost (IM) cells of ORS layers were reactive with UEA‐I at the stage where Henle's cells were keratinized, while the reactivity of UEA‐I was lost at the site of the completion of IRS keratinization where SBA reaction was detected. Staining of both UEA‐I and SBA was prominent in other ORS cells at the levels where SBA binding in IM cells became strong. The staining intensity increased up to the position of the follicular isthmus. In addition, a sugar residue recognized by Dolichos biflorus (DBA) was detected in differentiaed cells of ORS. In contrast, the DBA reaction was not found at all in cells of IRS, infundibulum, and epidermis. These findings identified a complexity of carbohydrate metabolism in the cells of different layers at various stages of keratinization. IM cells differentiate independently from other ORS cells but seem responsive to the degree of IRS keratinization. All ORS cells possess a unique sugar moiety not found in other keratinocytes either in the hair or epidermis.
Immunofluorescent studies for α‐actinin in cultured cardiomyopathic hamster heart cells
Authors: Li Jian , Lemanski Larry F. 
Published: February 2005

AbstractPrimary cultures of cardiac myocytes from normal and genetically cardiomyopathic (CM) newborn hamsters (strain UM X7.1) were analyzed by indirect immunofluorescent microscopy after 3, 5, 7, and 9 days in culture. The cultures were fixed in cold acetone and immunostained by an indirect method using FITC‐labelled anti‐α‐actinin to label the myofibrillar Z bands. Most normal and CM myocytes appeared round in shape after 3 days in culture. Normal cardiac myocytes began to exhibit cytoplasmic projections after 5 days in culture and their myofibrils usually showed parallel arrangements with respect to each other. The cardiac cells from CM hearts showed an obvious myofibril disarray. Moreover, projections formed later than normal. As the size of the cells increased, more and more projections formed in normal hamster myocytes during development. By contrast, most of the cardiomyopathic myocytes showed few projections even as late as 9 days in culture. Hence, the number of projections per cell was much less in cardiomyopathic myocytes than in normal, especially after 7 and 9 days in culture. These results suggest that cardiomyopathic cells have abnormal shapes in culture and, in particular, fail to form projections as in normal cells. Whether this unusual behavior is related to an abnormality of the membranes or cytoskeletal system in cardiomyopathic heart cells or to some other factor requires further study.
Whole population cell kinetics of jejunal and colonic epithelium in lactating dams
Authors: Cheng Hazel , Bjerknes Matthew 
Published: February 2005

AbstractPrevious studies make it likely that the response of the intestinal epithelium as a whole to lactation is different from that observed in the crypt population alone. We confirm this difference by whole population cell kinetics measurements of jejunal and colonic epithelium in mice that have been suckling pups for various lengths of time. We found that the fraction of cells in S phase in jejunal epithelium was significantly increased after only 1 week of lactation, maintained this elevated level after 2 weeks of lactation, but returned to normal during the third week of lactation. The cell number density in jejunum was also significantly higher after 2 and 3 weeks of lactation before returning to normal by 4 weeks. In the colonic epithelium no changes were found in the distribution of cells in G1, S, and G2 + M phases. However, a significant increase in cell number density was observed after 2 weeks of lactation, followed by a sharp decrease to a level significantly below that of normal mice after 3 and 4 weeks of lactation.We conclude that the observed significant increase in the fraction of S phase in jejunal epithelium of lactating mice is probably due to a smaller relative expansion of the villus population when compared with the expansion of the crypt population. Our data also indicate that a number of cell kinetic parameters in the intestinal epithelium of lactating mice are changing throughout the period of lactation. Thus the intestinal epithelium is probably not in a steady state during lactation.
High‐resolution scanning electron microscopic studies on the three‐dimensional structure of the transverse‐axial tubular system, sarcoplasmic reticulum and intercalated disc of the rat myocardium
Authors: Ogata Takuro , Yamasaki Yuichi 
Published: February 2005

AbstractThe three‐dimensional structure of the transverse‐axial tubular system, sarcoplasmic reticulum (SR), and intercalated disc of the rat left ventricle was examined by high‐resolution scanning electron microscopy after removal of the cytoplasmic matrices by the osmium‐DMSO‐osmium procedure. In the intermyofibrillar space, the transverse tubules (T‐tubules) are accompanied by longitudinally oriented axial tubules and together form a transverse‐axial system. The junctional SR is usually small but occasionally medium or large in size and couples with the T‐ or with the axial tubules. On the surface of the junctional SR facing the T‐ or the axial tubule, tiny junctional processes are seen. One or two sarcotubules, the so‐called Z‐tubules, frequently run parallel to the T‐tubule. The sarcotubules derived from the junctional SR or from the Z‐tubule run longitudinally or obliquely and form polygonal meshes around the myofibrils. On the surface of the SR at the H‐band level, small fenestrations of 12–40 nm in diameter, and tiny hollows 8–20 nm in diameter are seen. Bulbous swellings of the SR, the corbular SR, are preferentially seen near the Z‐band. The large and flat SR, known as the cisternal SR, intercalates among the SR meshes. In the subsarcolemmal space, the sarcotubules form a multilayered network (peripheral SR). The cisternal SR is frequently intercalated in these meshes and closely associated with the inner surface of the sarcolemma. The intercalated disc appears as a prominently undulated membrane demarcating the border between two adjacent heart muscle cells, and occasionally small projections 60–90 nm in diameter and 200–600 nm in length display on its surface.
Distribution pattern of acetylcholinesterase in early embryonic chicken hearts
Authors: Lamers Wouter H. , Geerts Willie J. C. , Moorman Antoon F. M. 
Published: February 2005

AbstractTo study the developmental appearance of acetylcholinesterase in early embryonic hearts, an enzyme‐histochemical study was carried out in chicken embryos ranging from cardiogenic plate to late tubular stages. Initially acetylcholinesterase is present in all cells of the (future) myocardium. When 13–14 pairs of somites have developed, i.e., shortly before blood propulsion starts, acetylcholinesterase selectively disappears from the ventral and lateral wall of the developing ventricle. Slightly later, when 18–19 pairs of somites have developed, acetylcholinesterase also disappears from the dorsal and anterior wall of the atrium. High concentrations of acetylcholinesterase remain present in the outflow tract and lower concentrations in a continuous tract along the lesser curvature of the heart, the atrial side of the atrioventricular canal, and the left wall of the atrium. In late tubular stages of heart development, acetylcholinesterase is reexpressed in the inner myocardial layer of the ventricle, i.e., in the developing trabeculae and the ventricular side of the atrioventricular canal, where it is continuous with the acetylcholinesterase‐expressing cells of the atrial side of the atrioventricular canal. The expression pattern of acetylcholinesterase in early embryonic chick hearts coincides with that of areas that control the conduction of the impulse and may reveal a cholinergic signal transduction system that is responsible for a coordinated contraction pattern of the myocardium prior to the development of the definitive conductive system.
Morphometry and frequency of afferent synaptic terminals in the rabbit dorsal–lateral geniculate nucleus
Authors: Carmona Ramón , Calvente Ruth , Abadía‐Molina Francisco , Abadía‐Fenoll Francisco 
Published: February 2005

AbstractMorphological and morphometric features of the retinal synaptic terminals (RLP) and cortical synaptic terminals (RSD) were analyzed in the αE sector of the rabbit dorsal–lateral geniculate nucleus (dLGN). A methodological approach was selected which allowed us to determine volume of the neuropil and elsewhere record variations in the size and distribution of the two types of terminals found in the three zones (superior, middle, and inferior) from up to down into which the αE sector of the dLGN was divided. After obtaining an isotropic, uniform, and pseudorandom (IUR) sample, the terminals were examined on the basis of a set of morphometric parameters. An analysis of these data showed the retinal terminals (RLP) to be more numerous and to occupy a greater total area of the neuropil in the dorsal (superior) zone of the nucleus, whereas the number and total area occupied by cortical terminals (RSD) did not vary in the superior, middle, and inferior zones. Upon comparing the two types of terminals, the RLP were larger and more widely distributed, the greatest differences between the two appearing in the dorsal (superior) zone of the dLGN.
Ultrastructure of substance P immunoreactive elements in the periaqueductal gray matter of the rat
Authors: Gioia M. , Bianchi R. 
Published: February 2005

AbstractSubstance P (SP) is a non‐opioid peptide that generates a potent, analgesia when injected into the periaqueductal gray matter (PAG)The aim of this study was to investigate the fine neuronal structures and synaptic circuits involved in SP action in rats by means of electron microscopy, using immunocytochemical (ICC) pre‐embedding methods. A conventional ultrastructural study, carried out to interpret the ICC data correctly, shows small sized nerve cell bodies with a high nucleus–cytoplasmic ratio; absence of an extensive granular endoplasmic reticulum; and few axo‐somatic contacts having symmetrical and asymmetrical junctions in equal proportions. The large neuropil is characterized by numerous thin unmyelinated axons and axodendritic synapses mainly showing pleomorphic vesicles and asymmetrical junctions.The ICC analysis showed moderately labeled nerve cell bodies with the same structural, synaptic, and dimensional features as the negative cells. In the neuropil SP immunoreactivity is shown by dendrites, synapses, and thin elements which are unidentifiable structurally. No SP terminals synapsing on SP nerve cell bodies were found and only occasional SP light labeled terminals synapsing on negative perikarya were seen. The SP boutons generally have pleomorphic vesicles and asymmetrical junctions.On the basis of these data a possible excitatory activity of PAG SP synapses could be hypothesized. This activity would take place on postsynaptic neurons generally at a dendritic level. Our ultrastructural findings give support to an excitatory role carried out by SP neurons of the PAG, as suggested by the role of PAG circuitry on spinal nociception.
Organization and development of the mineral phase during early ontogenesis of the bony fin rays of the trout Oncorhynchus mykiss
Authors: Landis William J. , Géraudie Jacqueline 
Published: February 2005

AbstractCharacterization of mineral deposition has been studied by electron optical methods during early ontogenesis of lepidotrichia, the bony fin rays, of the trout Oncorhynchus mykiss (the former Salmo gairdneri). The fin rays consist of an extracellular granular ground substance containing in part a network of collagen fibrils within the basal lamella of the fin dermoepidermal interface. Growth of individual rays proceeds in a proximodistal direction. The mineral phase appears as electron‐dense needle or plate‐like particles and is associated with the collagenous matrix. On analysis of progressively maturing tissue, the mineral was characterized as a poorly crystalline hydroxyapatite with Ca/P molar ratios in the range of 1.0–1.4, corresponding to distal and proximal areas, respectively. With selected‐area electron diffraction and dark field imaging of lepidotrichia, the mineral particles were found to be about 3–10 nm thick and 12–20 nm in length (along their crystallographic c‐axes), possibly aggregated into larger crystals 35–40 nm long observed with bright field microscopy. No definitive relation was found between either the c‐ or a,b‐axes images of the crystals and the periodic structure of collagen, which forms the framework for mineral deposition in this and in other vertebrate calcifying tissues.
Mandibular and molar vascularization in guinea pigs. Scanning electron microscopic study of corrosion casts
Authors: Aharinejad S. , Franz P. , Firbas W. , Fakhari M. 
Published: February 2005

AbstractThe vascularization of the mandible, molar teeth, and periodontal ligament of adult male and female albino guinea pigs (Cavia porcellus) was studied by scanning electron microscopy of vascular corrosion casts. Main routes of mandibular blood supply and drainage are shown, and the intrinsic vascular patterns of the mandible, the molars, and the periodontal ligament are described. Results are compared to findings in man and in other mammals.
Ontogenic appearance of three fatty acid binding proteins in the rat stomach
Authors: Iseki Shoichi , Kanda Tatsuo , Hitomi Masahiro , Ono Teruo 
Published: February 2005

AbstractWith the use of specific antibodies against three structurally different fatty acid binding proteins (FABPs), viz, liver FABP (L‐FABP), heart FABP (H‐FABP), and intestinal FABP (I‐FABP), the localization and relative amount of the immunoreactive proteins were determined by immunoblotting and immunocytochemistry in the gastric epithelium of rats during prenatal and postnatal development. H‐FABP immunoreactivity was first detected at embryonic day 20 (E20), with predominant localization in the parietal cells, whereas I‐FABP immunoreactivity was detected at the day of birth in the surface mucous cells. Both immunoreactivities were continuously localized in the same cell types with increasing intensity into adulthood. In contrast, the immunoreactivity for L‐FABP showed remarkable changes in intensity and localization during development of the rat stomach. It was first detected in the surface mucous cells of E19. In the first 2 weeks of postnatal life, i.e., the suckling period, L‐FABP immunoreactivity reached a peak in intensity and was localized not only in the surface mucous cells, but also in some of the parietal cells, brush cells, and endocrine D cells. In the following few weeks of weaning, the reactivity of surface mucous cells and parietal cells disappeared, leaving only a small amount of total L‐FABP immunoreactivity in the adult stomach, which was localized exclusively in the brush cells and D cells. These results revealed that the appearance of the three types of FABPs in the rat stomach is specific to cell types and developmental stages.
The ischiourethralis muscle of the rat: Anatomy, innervation, and function
Authors: Dail William G. , Sachs Benjamin D. 
Published: February 2005

AbstractThe ischiourethralis (IU), a striated perineal muscle presumed to be involved in sexual reflexes, was studied in the rat. The paired muscle arises from the penile crus and the penile bulb and unites in a raphe over the deep dorsal vein of the penis. Retrograde tracing studies show that the muscle is innervated by neurons in the dorsolateral nucleus of the lumbar spinal cord, a pudendal nerve motor nucleus which also innervates the ischiocavernosus muscle. Excision of the IU muscle did not interfere with the ability of males to display normal copulatory behavior, nor did it affect significantly the number and intensity of reflexive erections. It nevertheless remains possible that the IU may contribute to intense glans erection by compressing the deep dorsal vein.