bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vascular histodifferentiation in the chick chorioallantoic membrane: A morphometric study
Authors: Shumko John Z. , Defouw David O. , Feinberg Richard N. 
Published: February 2005

AbstractThis study presents a quantitative description of ultrastructural changes associated with focal histodifferentiation of the chick choriollantonic membrane (CAM) microvasculature. Early vessels (4–8 days of a 21‐day incubation period) were lined by a thin, but continuous endothelium which was characterized by punctate appositional contacts, an incomplete or absent basal lamina, and few plasmalemmal vesicles. During this stage, there was little ultrastructural distinction between CAM arterioles, capillaries, and venules. During the intermediate stage (9–13 days), the arteriolar endothelium displayed more extensive junctional apposition. In addition, the interstitial (periendothelial) space contained more collagen fibrils and increased cell volume densities, some of which resembled presumptive smooth muscle cells. In contrast to the arterioles, endothelial appositions of the venules and capillaries remained punctate during the intermediate stage. The interstitial space of the venules displayed an increase in cell and fibril densities but to a lesser extent than that observed in the arterioles. The capillaries did not exhibit any significant changes in their periendothelial spaces. By the late stage (14–18 days), a circular tunic containing several layers of presumptive smooth muscle cells surrounded only the arteriolar endothelium. The endothelium of both the arterioles and venules increased in mean thickness. The arterioles also displayed complex interdigitating endpthelial appositions. All CAM vessels exhibited a progressive increase in the number of endothelial plasmalemmal vesicles and a more complete basal lamina during the developmental stages. These observations served to distinguish differential patters of vessel maturation along the length of the microvascular system.
Response of the intermaxillary suture cartilage to alterations in masticatory function
Authors: Hinton Robert J. 
Published: February 2005

AbstractLike the condylar cartilage of the mandible, the cartilage at the intermaxillary suture in the rat is secondary in origin and persists well into adulthood. While the condylar cartilage is generally considered to be responsive to changes in its local biomechanical environment, little is known of the response of the intermaxillary suture cartilage to similar stimuli. In order to study the effect of changes in occlusal loads on intermaxillary suture cartilage metabolism, male weanling Sprague‐Dawley rats were divided into four groups: soft diet (to discourage molar mastication), incisor clipped (to discourage incision), incisor clipped/soft diet (both treatments), and control (untreated). At 39 days of age, the intermaxillary suture opposite the first molars was removed and compared to control tissue by using histological, histochemical, and biochemical analyses. Alcian blue—stained coronal sections demonstrated moderate decreases in staining intensity and decreased chondrocyte hypertrophy in the soft diet and incisor‐clipped groups. However, sutures in the incisor‐clipped/soft diet group showed a considerably reduced extent of cartilage and greatly diminished cartilage hypertrophy. [35S]‐sulfate incorportion (dpm/μg DNA) into acid‐insoluble proteoglycans was significantly reduced (P≤.01) in all three experimental groups compared to controls. [35S] incorporation was further reduced in the incisor‐clipped/soft diet group relative to both of the other experimental groups. Staining for alkaline phosphatase activity showed decreased intensity in the experimental groups and was almost absent in the incisor‐clipped/soft diet group. These data demonstrate the plasticity of the intermaxillary suture cartilage and provide circumstantial evidence that the observed changes in cartilage morphology and metabolism may be attributable to alterations in the local biomechanicla environment of the suture.
Lung lamellar body amphiphilic topography: A morphological evaluation using the continuum theory of liquid crystals: I. Closed surfaces: Closed spheres, Concentric tori, and Dupin cyclides
Authors: Stratton C. J. , Zasadzinski J. A. N. , Elkins D. 
Published: February 2005

AbstractThe structure and symmetry of the bilayers of in vivo phospholipid lung lamellar bodies is shown to be analogous to thermotropic smectic‐A liquid crystals and in vitro lyotropic multilamellar liquid crystalline liposomes. This structural similarity has led us to extend biophysical and geometrical principles that have long been used to predict the layer conformations in these in vitro systems to in vivo lung lamellar bodies. These configurations were demonstrated by electron micrographs of thin sections of rodent, monkey, and human lung lamellar bodies prepared by lipid‐retaining embedment procedures. The bilayer configurations in all species were consistent with the two geometries predicted by minimal energy solutions of a continuum theory of liquid crystals subject to the boundary conditions imposed by the amphiphilic nature of lung surfactant lipid: concentric (either closed or partially closed) spheres and Dupin cyclides. These bilayer arrangements in lung lamellar bodies were virtually identical to the bilayer configuration of in vitro multilamellar liposomes. The agreement between the two predicted configurations and our observations shows that multilamellar liquid crystalline bilayer aggregate organization is universal in any aqueous environment.
Microtubule‐granule relationships in motile human polymorphonuclear leukocytes
Authors: Ryder Mark I. , Weinreb Robert N. , Niederman Richard 
Published: February 2005

AbstractWe examined the relationship of microtubules to the granule organization in stimulated human polymorphonuclear leukocytes (PMNs). Electron microscopic (EM) observations of critical‐point‐dried PMNs revealed that only a portion of the granules appeared in close association to microtubules. These closely associated granules appeared to be attached to the microtubule via smaller‐diameter filaments. The remaining granules appeared either attached to microtubules at a further distance, via smaller‐diameter filaments such as actin, or unassociated with microtubules. EM observations of PMNs treated with either the microtubule promoter drug taxol or the mocrotubule depolymerization drugs nocodozole and colchincine revealed a redistribution of granules towards the nucleus. Granule clustering at the periphery of the cell was also noted with nocodozole and colchicine. With cytochalasin B, a uniform distribution of granules was noted. However, granule clustering was noted when PMNs were coincubated with cytochalasin B and colchicine. These results indicate that microtubules may have both a direct and indirect role (through other cytoskeletal elements) in the organization of PMN granules.
Ultrastructural evidence that specialized regions of the murine oviduct contribute a glycoprotein to the extracellular matrix of mouse oocytes
Authors: Kapur Raj P. , Johnson Lincoln V. 
Published: February 2005

AbstractPrevious studies have identified a glycoprotein (GP215) that is secreted by the murine oviductal epithelium and subsequently becomes sequestered within the perivitelline space of oocytes and developing embryos (Kapur and Johnson, Dev. Biol. 112:89–93, 1985; J. Exp. Zool. 238:249–260, 1986). The ultrastructural localizations of GP215 in the perivitelline space of ovulated oocytes and in the oviductal epithelium are described here. The glycoprotein is shown to be associated with a morphologically discrete extracellular matrix that provides a unique microenvironment for fertilization and early developmental events. In addition, putative secretory granules that contain this glycoprotein are observed in specific segments of the murine oviductal epthelium, suggesting regional differences in the composition of oviductal secretions.
Construction of a flexible airway model for teaching
Authors: Wang P. M. , Kraman Steve S. 
Published: February 2005

AbstractA method of producing flexible and strong models of canine airways is described. The animal's lungs are dried in inflation by using compressed air and then filled with silicone sealer. After this compound dries, the lung tissue is removed by corrosion by using NAOH. The result is a rugged, flexible, and anatomically faithful model of canine airways that is suitable for use in teaching.
Tracheobronchial epithelium of the sheep: IV. Lectin histochemical characterization of secretory epithelial cells
Authors: Mariassy Andrew T. , Plopper Charles G. , George Judith A. St. , Wilson Dennis W. 
Published: February 2005

AbstractConventional histochemical characterization of the mucus secretory apparatus is often difficult to reconcile with the biochemical analysis of respiratory secretions. This study was designed to examine the secretory glycoconjugates in airways using lectins with biochemically defined affinities for main sugar residues of mucus. We used five biotinylated lectins—DBA (Dolichos biflorus) and SBA (Glycine max) for N‐acetyl galactosamine (gaINAc), BSAI (Bandeiraea simplicifolia) and PNA (Arachis hypogea) for galactose (gal), UEA I (Ulex europeus)—for detection of fucose (fuc) in HgCl2 ‐fixed, paraffin‐embedded, serially sectioned trachea, lobar and segmental bronchi and bronchioles of nine sheep. Lectins selectively localized the carbohydrate residues in lumminal secretions, on epithelial cell surfaces, and in secretory cells. Inp proximal airways, the major carbohydrate residues in luminal secretions, cell surfaces, goblet cells, and glands were fuc and gal‐NAc. PNA reacted mainly with apical granules of < 10% of goblet cells, and gal residues were only detected in some of the mucous cells and on basolateral cell surfaces. Distal airways contained sparse secretion in the lumen, mucous cells containde weakly reactive fuc and gal‐NAc, and the epithelial surfaces of Clara cells contained gal. Sugars abundant in the airway secretions were also the major component of cells in glands. We conclude that there is a correlation between specific sugar residues in secretory cells, glycocalyx, and luminal secretions in proximal and distal airways. This suggests that lectins may be used to obtain information about airway secretory cell composition from respiratory secretions.
Characterization of prenatal growth and development in the crab‐eating macaque (macaca fascicularis) by ultrasound
Authors: Tarantal Alice F. , Hendrickx Andrew G. 
Published: February 2005

AbstractDiagnostic ultrasound is a valuable tool for the examination of various anatomical structures in vivo. Improvements in technology have increased its effectiveness and provided a noninvasive method for the in utero observation of a variety of structural and functional events. Ultrasound is utilized in our laboratory to monitor a variety of studies during embryonic and fetal development. Basic to these evaluations is the ability to assess normal growth and development. The cynomolgus, or crab‐eating macaque (Macaca fascicularis), has been observed in utero by ultrasound from early gestation to term. The earliest detection of implantation is by the identification of a developing gestational sac (GS), which may be visualized on gestational day (GD) 14–15. Positive identification of the GS on GD 16–18 and appearance of the embryo, yolk sac, and cardiac motion on GD 21–25 confirms pregnancy. Once the embryo is evident, measurements of the greatest length (GL) may be used to assess normal growth or to aid in the prediction of gestational age. During the fetal period, a variety of growth parameters aid in fetal evaluation. The gender of the fetus can be accurately identified as early as GD 70–75. An assessment of viability and condition can be determined by the observation of embryonic and fetal heart rates and gross body movement.
Inflammation of rat molar pulp and periodontium causes increased calcitonin gene‐related peptide and axonal sprouting
Authors: Kimberly C. L. , Byers M. R. 
Published: February 2005

AbstractWe have studied the response of nerve fibers containing calcitonin gene‐related peptide immunoreactivity (CGRP‐IR) to inflammation using a rat dental experimental system. Inflammation was induced by drilling tooth cusps to create pulpal exposures; the induced pulpitis and subsequent periapical lesions were studied 1–35 days later using standard CGRP immunohistochemistry and the avidinbiotin peroxidase method. The injury and resulting inflammation caused a disruption of CGRP‐IR nerve fiber location and arborization that varied depending on whether the initial injury was limited to the pulp tip or extended throughout the pulp horn. At shorter survival periods (24 hr, 3 days) nerve fibers were either decreased or bundled into the center of the pulp with sprouting along the wound border. At 6 days necrosis and acute inflammation had advanced to varying degrees, and CGRP‐IR fibers were extensively sprouted in the surviving pulp; the pulp also stained specifically for CGRP within 1–2 mm of the infalmed tissue at 6 days. At 35 days, we found total pulp necrosis in most teeth and the development of periapical bone loss, granulomatous tissue, and periapical abscesses. There was also an extensive increase in CGRP‐IR nerve fibers in the tissues surrounding sites of severe periodontal inflammation and necrosis. In some cases, macrophage‐like cells staining specifically for CGRP were near the abscesses. The results show important interactions between peptidergic nerve fibers and inflammatory cells, and are discussed in terms of the role of nerve fibers containing CGRP in neurogenic inflammation, mechanisms for intensification of CGRP immunoreactivity in affected fibers or neighboring cells, and implications for chronic inflammatory conditions, dental pain, and anesthesia.
Mitochondrial size and shape in equine skeletal muscle: A three‐dimensional reconstruction study
Authors: Kayar S. R. , Hoppeler H. , Mermod L. , Weibel E. R. 
Published: February 2005

AbstractIndividual mitochondria were reconstructed from ultrathin serial sections of selected muscle fibers in the M. semitendinosus of a horse, over a length of nearly two sarcomeres. Mitochondria were found to be highly variable, with size and complexity of single mitochondria increasing with the fractional part of a fiber occupied by mitochondria. In fibers with a mitochondrial volume density of less than 4%, corresponding to the mitochondrial content of fast‐twitch glycolytic fibers, mitochondria were generally rather simple cylindrical shapes, oriented parallel to the myofibrils. In fibers with a mitochondrial volume density of more than 7%, corresponding to the mitochondrial content of slow‐oxidative or fast‐oxidative glycolytic fibers, mitochondria were generally cylindrical at the A‐band and Z‐plate level of the muscle sarcomeres. However, these mitochondria often had transverse extensions or interconnections that occurred at the I‐band level. Volumes of individual mitochondria ranged from as small as a few thousandths of a μm3 up to several μm3 for the incompletely reconstructed portions of the largest mitochondria. Mitochondrial profiles that one would classify from single sections as subsarcolemmal were found to interconnect with other profiles deeper within the fiber. This suggests that it is unlikely that subsarcolemmal and interfibrillar mitochondria are two structurally distinct populations. However, we found no evidence of a reticulum completely interlinking all mitochondrial material in a muscle fiber.
Membrane systems of guinea pig myocardium: Ultrastructure and morphometric studies
Authors: Forbes M. S. , van Niel E. E. 
Published: February 2005

AbstractThe structure and quantitative contribution of membrane systems (transverse‐axal tubular system [TATS] and sarcoplasmic reticulum [SR]) have been investigated in the heart of the adult guinea pig. Although previous quantitative studies have been made of guinea pig myocardium, this is the first such study that has utilized tissue in which membrane system elements were clearly identified by selective staining (in this case by the osmium‐ferrocyanide [OsFeCN] postfixation method). Both membrane systems are highly developed in ventricular cells, but a TATS is essentially absent from atrial myocytes. The ventricular TATS consists principally of large‐bore elements which may be oriented transversely, axially, or obliquely, making numerous anastomoses with one another to form a highly interconnected system of extracellular spaces that penetrate to all myoplasmic depths of the ventricular cell. The cell coat that lines the lumina of these tubules is structured, containing fibrillar structures that run along the length of the tubule. The volume fraction (Vv) of the ventricular TATS is low (2.5–3.2%), in consideration of the qualitative prominence of the TATS in these cells.The relative total population of sarcoplasmic reticulum is higher in the atria (Vv of 10–11%) than in the ventricles (Vv of ca. 8%). In all guinea pig myocytes, several major structural divisions of SR can be discerned, which include network SR, junctional SR, corbular SR, and cisternal SR. Junctional SR (J‐SR) in the atrial cells is limited almost exclusively to peripheral saccules of junctional SR (PJSR), whereas both interior J‐SR and PJSR are present in the ventricle. Two distinct morphological types of PJSR appear in atrial cells, including both flattened and distended saccules, the latter resembling PJSR of lower vertebrate heart. Spheroidal bodies of SR with opaque contents (corbular SR) are prominent at or near Z‐line levels of the sarcomeres of atrial and ventricular cells. Cisternal SR is likely a subset of network SR, but some examples appear related to rough endoplasmic reticulum. An overall impression obtained from this study is that guinea pig atria are composed of structurally primitive cells, whereas the ventricular cardiac muscle cells are more highly developed entities.Freeze‐fracture replicas were prepared by Ms. Bonnie Sheppard of the Central Electron Microscope Facility of the University of Virginia School of Medicine. We are grateful as well to Ms. Lisa Kremer for her skillful preparation of the electron micrographs used for the stereology studies reported in this communication. Special thanks go to Mr. Guenter Lamprecht of Carl Zeiss, Inc., Thornwood, New York, for providing access to the Zeiss EM 902 instrument, and to Mr. Jean‐Marc Theler (Department of Physiology, University of Virginia School of Medicine) for valuable discussions concerning aspects of this research.
Human abductor pollicis brevis muscle “divisions” and the nerve hila
Authors: Simard Thérèse , Roberge Jean 
Published: February 2005

AbstractThe interpretation of neuromuscular impairement may be aided by an analysis of functional anatomic factors. The anatomy of the abductor pollicis brevis (APB), a muscle used for skilled movements, was investigated in 19 embalmed hands, and the muscular divisions joining the common tendon at different sites were reproduced on clear vinyl sheets. The median nerve pathway to thenar muscles was followed to where it divides to the APB nerve and to the sites of the main terminal hila. Transverse (x) and longitudinal (y) muscle axes were established with the aid of landmarks to reproduce the nerve pathway on the skin surface. In the rather thick APB, three groups of six muscular heterogeneous divisions were regularly present. The dorsal aponeurotic expansion of the thumb receives the first group. The second group forms a continuous vertical line from the base to the body of the first phalanx. The outside site of its lateral tubercle takes the central tendon from the penniform third group. Hence, a reverse figure‐seven distal insertion can be observed. The deepest medial (V2) and the most superficial lateral (V3) divisions had the highest mean diameters. The APB nerve fall between V2 and V2′ and its line of projection supplied a guideline to establis an x axis at the proximal one‐third of the muscle. The nerve hila plotted in relation to the x‐y axes revealed a mode of location. The classical description of a thin APB muscle, made up of two bellies of parallel fibers seems incorrect. The APB nerve is not found on the deep aspect of the muscle as stated earlier, but within the muscle. The well‐innervated muscular divisions point to the possibility of their individual use. The APB neuromuscular projection to the skin should allow more accureate fundamental EMG studies of the thumb and therefore provide a basis for more effective treatment in cases of impaired APB.
Granular epithelioid cells of the kidneys in salmon adapted to fresh‐ and seawater
Authors: Christensen J. A. , Mikeler E. , Bohle A. 
Published: February 2005

AbstractThe occurrence of granular epithelioid cells in the kidney arterial vessels was studied in one‐and two‐year‐old Atlantic salmon during the physiological fresh‐ and seawater periods. The purpose of this study was to make long‐term comparison on the morphology of the renin angiotensin system in the same fish species. One‐year‐old salmon living in freshwater had a statistically significant higher number of granular epithelioid cells (39.9 ± 8.3/mm arterial vessel) than the two‐year‐old fish living in seawater (29.8 ± 5.2/mm arterial vessel, P < 0.00001). There was also a significant difference from month to month between the groups (P < 0.05), but not within the groups (P > 0.07 freshwate, P < 0.3 seawater). With the electron microscope the granules were found evenly distributed within the cytoplasm. They were of high electron density and lined by a single membrane. The granules were composed of a finely granular material. The recorded data on length and weight showed that all fish ate and developed normally. From our results and the available literature, we conclude that in primitive vertebrates, the renin angiotensin system is primarily involved in renal circulation, with vasoconstriction on the afferent side of glomerulus.
An electron microscopic study of cells with steroid‐secreting morphology in the paraaortic lymph node of the hamster
Authors: Kimura Michio , Tohya Kazuo , Kuroiwa Kyo‐Ichi 
Published: February 2005

AbstractClusterd cells with steroid‐secreting morphology (SH), located within the paraaortic lymph node (PLN) capsules of normal and pregnant female golden hemsters, were examined by light and electron microscopy. Hydroxysteroid dehydrogenase (HD) activity of the SH cell cluster also was examined by histochemical techniques. The cluster was composed of mostly packed SH cells and surrounding mesenchymal cells. Individual SH cells posessed prominent smooth endoplasmic reticulum, well‐development Golgi complexes, some lipid droplets, and numerous mitochondria containing tubulovesicular cristae common to mammalian SH cells. Intermediate‐type junctions were often observed between SH cells. The same SH cells were rarely detected in the subcapsular sinus and in the cortical parenchyma of the PLN. Early oophorectomy of the hanster resulted in cytopolasmic degeneration of the SH cell at day 5 after the operation. On the other hand, normal adult male hamsters possessed similar PLNs, but mo SH cells were recoginzed in the nodos. The present hiustochemical preparation of normal PLNs revealed moderate‐to‐strong HD activity, probably associated with SH cell clusters, in the limited regions of the capsules.Based on the present ultrastructural and histochemical findings, it is proposed that the SH cell cluster consists of steroid producing cells.