bluuebunny/crossref_metadata_2025_split huggingface dataset:
Scanning electron microscopy of mouse muscle microvasculature
Authors: Holley John A. , Fahim Mohamed A. 
Published: February 2005

AbstractThe surface morphology of the microvasculature from mouse skeletal muscle was studied by scanning electron microscopy. Cell surfaces were exposed by digesting away extracellular collagen and other matrix by a simple HCl treatment. Four distinct subdivisions of the microvasculature (arterioles, precapillary arterioles, capillaries, and venules) were identified based on marked differences in surface features. Arterioles of 20–10 μm diameter had a discontinuous, single layer of smooth muscle cells encircling the vessel. These smooth muscle cells had an uneven surface with shallow grooves and depressions that were often oriented parallel to the longitudinal cell body axis. The underlying arteriolar endothelial surface was also rough with long ridges separating shallow furrows that were oriented parallel to the vessel length. As the arteriolar size decreased, the perivascular cell were found further apart, they became smooth surfaced, and were oriented preferentially parallel to the vessel. The endothelium of the precapillary arterioles, as well as, capillaries and venules had smooth surfaces. Venules had a discontinuous layer of flat, smooth surfaced pericytes. Morphologically distinct groups of smooth muscle cells (i.e., precapillary sphincters) were not found. Although pericytes normally associated with capillaries and other vessels were often removed during tissue processing, most cells and their surface feature were generally well preserved.
Epidermal growth factor, renin, and protease in hormonally responsive duct cells of the mouse sublingual gland
Authors: Gresik Edward W. , Barka Tibor 
Published: February 2005

AbstractIn the striated ducts of the sublingual glands of normal adult male, but not female, Swiss‐Webster mice a few scattered cells have apical secretion granules. These sublingual duct cells resemble the granular convoluted tubule (GCT) cells of the submandibular glands of adult female mice, in that they are smaller than submandibular GCT cells of adult males, and contain fewer apical granules, and prominent basal striations. These cells stain immunocytochemically for epidermal growth factor (EGF), renin, and protease A. Such granular striated duct cells could be induced in the sublingual glands of adult female mice by treatment with either testosterone propionate or thyroxine; the two hormones give simultaneously acted synergistically in this induction.
An electron microscopic analysis of the left phrenic nerve in the rat
Authors: Langford Lauren A. , Schmidt Robert F. 
Published: February 2005

AbstractIn this electron microscopic study, the axonal categories in the left phrenic nerve at its entrance to the diaphragm have been determined. At a level 3 mm rostral to the diaphragm, the left phrenic nerve contains approximately 700 axons: 57% are myelinated and 43% are unmyelinated. The dorsal root ganglion cells give rise to 31% of the myelinated axons and the ventral root contributes 69%. Of the unmyelinated axons, the dorsal root ganglion cell contributes 59%, the cervical sympathetic chain 24%, and 17% course through the ventral roots. These ventral root unmyelinated axons are presumably preganglionic efferents since the proximal stump of the ventral root showed no decrease in unmyelinated axons after ventral rhizotomy.
A simple method of lung perfusion fixation
Authors: Coalson Jacqueline J. 
Published: February 2005

AbstractA simple perfusion apparatus modified from procedures used and published in renal studies is presented and discussed. The buffer and fixative solutions to be perfused are placed in closed reservoirs under 20 mm of Hg pressure which is provided by a constant inflow of air from an air inflow valve present in any routine laboratory. The pressure is monitored by a sphygmomanometer gauge and adjusted with an air control valve. The perfusate solutions are kept at 37°C. The oncotic‐osmotic characteristics of routine buffer and fixative perfusates are presented and discussed. The perfusion technique utilized in a cat model is detailed. The technique does not require sophisticated equipment and yet perfusion conditions can be carefully monitored and controlled.
Structural and cytochemical changes in astrocytes from the brain periventricular zone of the copper‐deficient blotchy mouse
Authors: Terr L. I. , Weiner L. P. 
Published: February 2005

AbstractPorphyrin‐ and endogenous peroxidase‐containing accumulations of cytoplasmic inclusions in astrocytes of the hypothalamic periventricular and arcuate nuclei and periventricular areas of the lateral ventricles except for ependymal astrocytes were observed by fluorescent microscopy and histochemical techniques in the wild type, C57BL/6J, and tabby mice. These cells can be also visualized with phase contrast and dark‐field techniques or by staining sections embedded in polymerized resin with toluidine blue. The brains of heterozygous females and hemizygous males for the blotchy allele (mottled locus on the X‐chromosome) failed to show this specific class astrocytes. The findings described are possibly due to defective copper metabolism in mottled mutants which may include a number of other related abnormalities, including reduced activity of copper‐dependent enzymes such as porphyrin‐containing peroxidases. Sexual differnce in the number of the accumulations in the anatomically and physiologically normal tabby mouse was clearly expressed.
The blood–testis barrier in the toad (Bufo arenarum hensel): A freeze‐fracture and lanthanum tracer study
Authors: Cavicchia Juan C. , Moviglia Gustavo A. 
Published: February 2005

AbstractIntercellular junctions between Sertoli cells in the toad testis were studied by freeze‐fracture and electron‐opaque intercellular markers. These junctional specializations are characterized in thin sections by a series of focal fusions on the outer leaflets of both adjacent cell plasmalemmas, associated with bundles of fine filaments in the subjacent Sertoli cell cytoplasms. However, the wide subsurface cisterna of the endoplasmic reticulum, a component constantly associated with Sertoli cell junctions in mammals, is absent in the toad. The intravascularly injected lanthanum hydroxide, used as a tracer compound, gains access to the seminiferous tubules and surrounds spermatogonia and leptotene spermatocytes, but is persistently excluded from germ cells in later stages of development. This indicates that, as is the case in the mammalian testis, a permeability barrier to lanthanum is established which isolates all germ cells beyond leptotene spermatocytes.Freeze‐fracture reveals the characteristic occluding junctions between Sertoli cells, but a variation in their geometric patterns was clearly observed in different regions of the toad seminiferous epithelium. The membrane‐fractured faces of Sertoli cells embracing differentiating spermatids exhibit a deep junctional complex: up to 50 rows of particles between adjacent Sertoli cells separate these late germ cells from the periphery of the seminiferous tubules. Sertoli cells surrounding early germ cells generally exhibit, instead, a discontinuous, poorly developed network of interconnected rows of particles with few widely spaced strands. This seems to permit the percolation of the intercellular marker in areas of the seminiferous epithelium containing spermatogonia and leptotene spermatocytes.
Effects of prior culture or isoproterenol injections on the regeneration of rat submandibular gland autografts
Authors: O'Dell Norris L. , Sharawy Mohamed , Pennington Catherine B. 
Published: February 2005

AbstractThis study compares the acinar cell regnerative response in submandibular gland (SMG) autografts that were cultured before grafting to the rat tongue with the acinar cell regenerative response in direct SMG autografts to the tongue. In addition, the effects of isoproterenol on direct SMG autografts were studied. A portion of the left SMG was excised from each rat and cut into fragments which were autografted either immediately into the middle one‐third of the rat's tongue; or were cultured for 1, 4, or 7 days and then autografted to the donor's tongue. After 8 weeks the rats were killed and the tongues were removed and processed for light microscopic study. The histologic preparations showed evidence of cytodifferentiation into acinar cells in four of the previously cultured SMG autografts. Some of the direct SMG autografts did not contain acinar cells, whereas other direct. SMG autografts contained numerous acinar cells and even straited ducts. In the SMG autografts that were cultured for 1 day before autografting and in the direct SMG autografts, that contained ductlike structures that were apparently connected to the epithelial surface of the tongue. Lastly, isoproterenol appeared to accelerate the regenerative responses in some of the direct SMG autografts, and the drug caused acinar cell hypertrophy in two of the direct SMG autografts.
Afferent and efferent axons in the medial and posterior articular nerves of the cat
Authors: Langford Lauren A. , Schmidt Robert F. 
Published: February 2005

AbstractThe goal of this study is to determine the average numbers of afferent axons and postganglionic autonomic (sympathetic) efferent axons supplying the cat knee joint through the medial and posterior articular nerves. Interestingly, both nerves are composed primarily of unmyelinated axons. Only 20% of the axons in the medial articular nerve are myelinated, with the overwhelming majority, 80%, being unmyelinated. The posterior articular nerve has 78% unmyelinated and 22% myelinated axons. Neither nerve contains ventral root efferent axons. The sympathetic chain, in both nerves, contributes no myelinated and only 50% of the unmyelinated axons. The medial and posterior articular nerves are therefore predominantly afferent, since all myelinated and the remaining 50% of the unmyelinated axons arise from the dorsal root ganglion cell. The ratio of afferent unmyelinated to myelinated axons is 2:1. The roles of these afferent unmyelinated axons must now be considered in regard to joint kinesthetics and pain.
Morphological relations between the receptor neurons, sustentacular cells and Schwann cells in the olfactory mucosa of the salamander
Authors: Rafols José A. , Getchell Thomas V. 
Published: February 2005

AbstractThe morphological characteristics of olfactory receptor neurons and their relations to the sustentacular cells and to the sheath cells of Schwann in the olfactory mucosa of the salamander (Ambystoma maculatum et tigrinum) were studied using a modification of the rapid Golgi technique. The bipolar receptor neurons had a fusiform‐shaped cell body whose apical pole gave rise to a surface‐reachig dendrite and a basal pole which gave rise to an axon. The length and width of the dendrite, although variable, were positively correlated with the relative depth at which the cell body was located in the sensory epithelium. Beyond the initial segment, the axon had a sinuos course prior to its entrance into the lamina propria. Within the lamina propria, the axons were associated with the sheath cells of Schwann to for the olfactory nerve fascicles. The processes of adjacent sheath cells formed an elaborate network of continous cavities through which the axons coursed.Two morphologically distinct varieties of sustentacular cells, designated types I and II, were found in the sensory epithelium. Both types had a columnar profile cnsisting of an elongated cell body, a central stalk, and a basilar expansion of the stalk found at the junction of the epithelium with the lamina propria. The central stalk of type I sustentacular cells was unbranched, whereas that of type II cells gave rise to riblike processes from which cytoplasmic veils extended to envelop the cell bodies of receptor neurons. The basilar expansions were found in close apposition to the wall of capillaries or to acinar cells of Bowman's glands located in the most superficial region of the lamina propria. The morphological relationships and possible interdependencies among receptor neurons, the types of sustentacular cells, and the sheath cells are discussed.
A numerical identification syterm for airways in the lung
Authors: Mortensen J. D. , Young Johanne D. , Stout Lisa , Stout Alison , Bagley Barry , Schaap Robert N. 
Published: February 2005

AbstractA numerical sytem for identifying airways at any level in the tracheobronchial tree has been develop which appears to be simple, logical, and accurate. The system has successfully used in the author' laboratory to expedite morphometric studyes of the conduciting airways in the tracheobronchial tree.Three simpe and direct criteria or rules have been fomulated for assignment of an airway identification number (AIN) to any specific pulmonary airway, according to this identification system.Some specific applications of this AIN system have been enumerated and several limitations that the authors have recoginzed have been described.Workers in the fields of bronchial morphometry and anatomy are invited to consider the possible theoretic and practical utility of this airway identification system.
Development of a method for quantitative stress analysis in bones by three‐dimensional photoelasticity
Authors: Bianchi Rossella , Clerici Paolo , Vizzotto Laura , Miani Alberto 
Published: February 2005

AbstractComparative critical examination of methods suitable for studying stress in bones have shown that the three‐dimensional photoelastic method is one of the most reliable. Described herein is the method for obtaining, by fusion, full‐scale models in epoxy resin, that are exactly equivalent to external shape of the prototypes.This technique offers the advantages of being applicable without variation to any bone segment and of enabling a large number of additional resin castings to be made from the same mould. Hence it is possible to produce a very large number of copies of the same bone segment that will be suitable for comparative studies of different load situations.As an example, quantitative data expressing both surface and internal tension trends in the proximal third of a normal human femur are given.
Blood vessels of the Peyer's patch in the mouse: II. In vivo observations
Authors: Yamaguchi K. , Schoefl G. I. 
Published: February 2005

AbstractA technique was developed that allowed the in vivo observation of Peyer's patches in the mouse for several hours. Untreated animals and animals depleted of lymphocytes were used. In this species, blood vessels associated with the lymphoid nodules are readily visible through the thin serosal muscle coat. High‐endothelium venules are recognized by the large number of refractile cells that adhere to the luminal surface. A colloidal carbon suspension injected intravenously labeled high‐endothelium venules and was only rarely seen in arterial and capillary segments or in venules of the gut parenchyma. When fluorescein isothiocyanate‐labeled (FITC‐labeled) syngeneic spleen cells were injected, they appeared in vessels of the Peyer's patch within a few seconds and began to adhere to the luminal surface of high‐endothelium venules. In untreated animals, peak numbers of fluorescent cells were reached after about 20 min. Many adhered but some were swept away. In lymphocyte‐depleted animals, however, peak numbers were reached after only a few minutes and most cells remained attached.
Blood vessels of the Peyer's patch in the mouse: III. High‐endothelium venules
Authors: Yamaguchi K. , Schoefl G. I. 
Published: February 2005

AbstractHigh‐endothelium venules of mouse Peyer's patches were examined by scanning electron microscopy, and a quantitative assessment was made of the location of lymphocytes in relation to endothelial cells. Untreated mice and mice with markedly depressed levels of circulating lymphocytes were used. Lymphocytes were divided into adhering and migrating cells and as to association either with the body of the endothelial cell or with its cell border. Over 90% of all adhering cells and the great majority of migrating lymphocytes were located at the cell border. The exception was one animal in which most migrating lymphocytes appeared to penetrate the endothelial cells. Our data lend strong support to the currently held view that most migrating lymphocytes traverse the endothelium by following an intercellular path but that, under certain conditions, lymphocytes may penetrate the cytoplasm of endothelial cells.
The soleal line
Authors: Mysorekar Viswanath Ramrao , Nandedkar Asha Narayan 
Published: February 2005

AbstractThe soleal line in 167 left and 163 right tibiae has been studied. The line often does not follow the textbook description. It commences well below the fibular facet and ends well down nearer the middle of the bone on the medial border. It generally shows mixed characters of a line, a wide line, a ridge, ora groove. The line is frequently absent in the upper third. In the middle third, it is seen as a wide line or as a ridge varying from 1 to 2 mm in height. In the lower third the line presents itself as a ridge. In the middle and lower thirds, the line is often seen as a depression varying from 1 to 2 mm in depth. The line shows a left‐sided dominance.
Response of epididymal duct to the temporary depletion of spermatozoa induced by testicular irradiation in mice
Authors: Abe Kazuhiro , Takano Hiroko , Ito Takashi 
Published: February 2005

AbstractThe mouse epididymal duct can be histologically divided into five segments (I‐V), and the principal cells in segment II appear to secrete periodic acid‐Schiff (PAS)‐positive material into the lumen. In this study, male dd‐mice received one, two, or four 800‐R doses of radiation beginning at age 50 days. Mice receiving multiple doses were irradiated at 1‐week intervals.After irradiation, marked depletion of spermatozoa, or aspermia, occurred in the epididymal duct for 2 to 16 weeks after a latency period of 3 to 4 weeks according to the times of irradiations. During oligospermia or aspermia, PAS‐positive inclusions apeared in the principal cells in segment IV. The inclusions occupied a supranuclear position and appeared as round granules and globules measuring 2–15 μm in diameter, and increased in number, size, and staining intensity with time. They disappeared after reappearance of spermatozoa. The findings suggest that PAS‐positive material may bind to spermatozoa and, if not bound, is reabsorbed by the principal cells in segment IV and deposited as intracellular inclusions, and the prinicipal cells in segment IV and capable of digesting the accumulated PAS‐positive mateial.
Actin filaments in the ameloblast of the rat incisor
Authors: Nishikawa Sumio , Kitamura Hironori 
Published: February 2005

AbstractThe distribution of actin filaments in the inner enamel‐secretory ameloblast of the rat incisor was examined by labelling with heavy meromyosin. Actin filaments were mainly located in the long axis of the cell beneath the cell membrane. They tended to be more numerous in Tomes' process than in the cell body. Some filaments were associated with microtubules, with other actin filaments, and coated vesicles. Possible relation of the actin filaments to cell motility, stabilization of some, and movement of other cellular components is discussed.
Ultrastructural evidence for a reabsorptive role by intrarenal veins
Authors: Jones Warren R. , O'Morchoe Charles C. C. 
Published: February 2005

AbstractIntrarenal veins, although known to have thin walls, are considered to be simple conducting vessels. Using light‐ and electron microscopy, the distribution and structure of named intrarenal veins was examined qualitatively and quantitatively in rat kidneys fixed by retrograde arterial perfusion. Although the venous system follows the pattern of arterial branching in general, a class of intracortical veins similar in appearance to interlobular veins but without a companion artery was found in the present study. It is suggested that these vesels be designated intralobular veins. Structurally, we have found intrarenal veins to be surprisingly similar to peritubular capillaries both in respect to their spatial relations to renal tubules as well as ultrastructurally. Like peritubular capillaries, the majority of the wall of intrarenal veins is intimately apposed to renal tubules. This fraction decreases centrally, values of 0.83 being obtained in intralobular veins, 0.69 in interlobular veins, and 0.56 in arcuate veins. The walls of intrarenal veins are comprised of little more than an endothelium, which, like peritubular capillaries, is remarkable for its thinness, high density of fenestrae, and lack of extraintimal elements. Endothelial thickness was not significantly greater in either interlobular or arcuate veins than in peritubular capillaries; the fenestrae were, however, about twice as frequent in peritubular capillaries as in interlobular or arcuate veins and 35 times more frequent than in interlobar veins. The size and numerical and volume densities of uncoated endocytotic vesicles did not differ significantly between peritubular capillaries and any of the intrarenal veins. Based on their marked qualitative and quantitative similarities to peritubular capillaries, we conclude that, like the latter, intrarenal veins are capable of sustaining passive transport between plasma and interstitium.
Morphometric analysis of the remodeling of the rat pulmonary epithelium during early postnatal development
Authors: Vidić Branislav , Burri Peter H. 
Published: February 2005

AbstractIn the rat lung the alveoli are formed in the early postnatal period. Within 3 weeks the alveolar surface area increases more than five‐fold and the saccular lung reaches its mature structure. In order to analyse the changes in the compartments of the parenchymal tissue, the lungs of three animals per group aged 4, 13, and 21 days, respectively, were investigated by means of electron microscopic morphometry.Whereas the capillarisation of the interalveolar septa almost doubled in the period investigated, the endothelium and alveolar epithelium increased their share of the septal tissue at the expense of the interstitial compartment. The cellularity of the interstitium decreased markedly with age, the ratio of cells to interstitial spaces falling from 5.1 to 1.7. Within the epithelium, the type II cell population increased its mass almost six times, representing 58% of the alveolar epithelial volume at 3 weeks. Accordingly, the portion of alveolar surface area covered by type II cells was highest on day 21, with 9% versus 5.6% on day 4, and around 3% in a normal adult lung.The observed quantitative structural changes are discussed in the light of the functional demands of the organ: the need for an expanding alveolar surface area to be covered by a thin epithelial lining layer, the maintenance of a thin air‐blood barrier, and a quantitatively adapted secretion of alveolar surfactant.