bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of endosteal bone‐lining cells from fatty marrow bone sites in adult beagles
Authors: Miller Scott C. , Bowman Beth M. , Smith James M. , Jee Webster S. S. 
Published: February 2005

AbstractBone‐lining cells cover the majority of trabecular bone surfaces in adult long‐lived mammals. The morphology, ultrastructure, and population density of bone‐lining cells was investigated in several fatty marrow trabecular bone sites in adult beagles of different ages. Although there is a low population density of bone‐lining cells on bone surfaces, their total numbers greatly exceed the numbers of osteoblasts and osteoclasts found on these bone surfaces. In one of the bone sites studied, there are significantly fewer bone‐lining cells in very old beagles (12–16 years old) when compared to young adult beagles (1.5–3 years old), otherwise there are no differences in the cell population that could be attributed to aging. Bone‐lining cells are flattened against bone surfaces and have flat or sometimes ovoid‐shaped nuclei which are often located adjacent to areas in the fatty marrow where capillaries are found. When viewed in the electron microscope, bone‐lining cells contain few organelles, and the attenuated cytoplasm of these cells is well extended over bone surfaces. The bone‐lining cell cytoplasm does not appear to form a continuous layer over the bone surface, as numerous gaps and spaces are seen. Bone‐lining cell processes are frequently joined by junctions morphologically similar to gap junctions. Between the lamina limitans of the bone matrix and the bone‐lining cell, as well as between the bone‐lining cell and the adjacent fat cells, there are layers of connective tissue containing collagenous fibers and other amorphous material. These findings are discussed in relation to the possible role of bone‐lining cells in the regulation of mineral homeostasis.
Ultrastructural classification of paracrystalline inclusions in untreated and estrogen treated human Leydig cells
Authors: Payer Andrew F. 
Published: February 2005

AbstractUltrastructural examination of untreated and estrogen‐treated human testes revealed for the first time five types of paracrystalline inclusions in the cytoplasm of Leydig cells. The distinctions between each type of inclusion were based on longitudinal and cross‐sectional ultrastructure. The inclusions were not found in Leydig cells containing Reinke crystals, nor were different types of inclusions found in the cytoplasm of the same cell. One form of inclusion or Reinke crystals were occasionally found in the nucleus. Some Leydig cells with intranuclear inclusions contained the same or a different type of inclusion in the cytoplasm. The present study revealed five types of paracrystalline inclusion in contrast to the one or two types described in previous reports. A possible explanation for this difference is that earlier investigators based their observations on small pieces of tissue obtained from biopsy, while the present data were obtained by studying many regions of each testis. All five types of paracrystalline inclusions were found in relatively normal as well as azoospermic (estrogen‐treated) testes.
Heterogeneity of tight junction morphology in extrapulmonary and intrapulmonary airways of the rat
Authors: Schneeberger Eveline E. 
Published: February 2005

AbstractIn the present study morphology of tight junctions was related to the various cell types lining extrapulmonary and intrapulmonary airways of the rat. Freeze fracture replicas were prepared from extrapulmonary airway epithelium derived from the cartilagenous and membranous sides of upper, middle, and lower thirds of the trachea. Intrapulmonary airway epithelium was obtained from airways < 1 mm in diameter. Tight junction fibrils on the P fracture face were organized into three types of patterns. Type 1: parallel, sparsely interconnected lumenal fibrils with large ablumenal fibril loops. Type 2: richly interconnected lumenal fibrils with large ablumenal fibril loops. Type 3: narrow network of interconnected fibrils. On the E fracture face complementary grooves were organized in a similar pattern. Ciliated cells on both sides and all levels of the trachea were associated with type 1 junctions. In intrapulmonary airways, however, the junctional pattern of ciliated cells changed to type 2. Brush cells at all levels of the airways were bounded by type 2 and occasionally by type 1 junctions. Secretory cell junctions displayed the following patterns: Mucous cells were bounded solely by type 3, serous cells by either types 2 or 3, and Clara cells predominantly by type 2. Cells tentatively identified as intermediate cells displayed all three junctional patterns. The number of parallel fibrils comprising tight junctions was higher in extrapulmonary as compared to intrapulmonary airways. No difference was seen in the various locations sampled in the trachea. Gap junctions were observed between secretory cells of extrapulmonary but not intrapulmonary airways. These observations are discussed in relation to current physiologic data.
Connective tissue arrangement in respiratory airways
Authors: Young Christine D. , Moore G. William , Hutchins Grover M. 
Published: February 2005

AbstractConnective tissue provides dynamic stability to the architecture and mechanical function of the lungs. This study examines the parenchymal connective tissue components of the alveolar ducts, their associated respiratory bronchioles and respective alveoli. Thick sections 100μ and 200μ, and serial sections at 8μ of lungs of different ages were examined histologically after fixation in distention. The varying proportions and spatial architecture of the collagen and elastic fibers and the packing and spatial interrelationships of alveoli were studied using graphic serial reconstruction. Alveolar mouths typically have a polygonal configuration as they arise from the airways. Denser connective tissue passes through the polygonal array and forms a helix encircling the airway. Polygonal packing of alveolar mouths provides a mechanically stable ductular structure with conservation of materials. A helical modification of the polygonal arrangement permits reversible changes in linear and circumferential airway dimensions.
A simultaneous comparison of the cells of blood, renal hilar and thoracic duct lymph in the dog
Authors: Garber S. L. , O'Morchoe P. J. , O'Morchoe C. C. C. 
Published: February 2005

AbstractA simultaneous morphological and quantitative profile was obtained of the cells of blood, thoracic duct, and renal hilar lymph in the dog. Monolayer cytocentrifuged preparations were used to determine the number, type, and size of cells in the three compartments. The cell count of renal lymph was not related to that of blood or thoracic duct lymph. There was a greater percentage of lymphoid cells in the afferent lymph than could be accounted for by the random movement of cells from the blood to the lymph. Thus, there appeared to be a selective transit of cells from blood to lymph. Monocytes and neutrophils were largely absent from the thoracic duct lymph; however, eosinophils were present. Cells were observed in hilar lymph that were characteristic of cells subjected to antigenic stimulation. It was concluded that lymphocytes have a preferential pathway from blood to lymphatic and in the course of this pathway they undergo a change which is consistent with an active immunological role.
Further studies on catecholamine‐containing specific endothelial granules in carp cerebral veins. A fluorescence histochemical and electron microscopy study
Authors: Iijima Tadahiko , Wasano Takeo 
Published: February 2005

AbstractThe effects of noradrenaline (NA), L‐3, 4‐dihydroxyphenylalanine (L‐DOPA), 5‐hydroxydopamine (5‐OHDA), 6‐hydroxydopamine (6‐OHDA), and reserpine (RES) on the uptake, accumulation, and release of amines in cate‐cholamine‐containing specific endothelial granules (SEG) of carp cerebral veins and their mode of formation were examined by fluorescence histochemistry and electron microscopy. The intramuscular injection of NA (4 mg/kg) or L‐DOPA (200 mg/kg) resulted in an increase in both the fluorescence and electron density of SEG. After the administration of false neurotransmitters, 5‐OHDA (190 mg/kg) or 6‐OHDA (200 mg/kg), the venous endothelia fluorescence almost completely disappeared but the SEG electron density increased. Following the injection of RES (15 mg/kg), the fluorescence intensity and SEG electron density showed no sign of decrease, as was expected, but in fact increased. It is suggested that the SEG are able to take up and accumulate exogeneous amines and that these mechanisms are RES‐resistant. The electron density of SEG increased in proportion to the amount of amines in the SEG. The swelling and fragmentation of rough endoplasmic reticulum cisternae and the accumulation of dense material within the cisternae suggests the possible participation of these organelles in SEG formation.
The autonomic innervation of the human urinary bladder, bladder neck and urethra: A histochemical study
Authors: Klück P. 
Published: February 2005

AbstractThe autonomic innervation of smooth muscle in fresh biopsy specimens of the human urinary bladder, bladder neck and urethra has been examined using specific neurohistochemical techniques. Acetylcholinesterase‐containing nerve fibers have been demonstrated amongst the smooth muscle cells in all the biopsy samples. Enzyme‐positive fibers formed a plexus, the density of which varied dependent upon the region from which the biopsy material was obtained. Catecholamine (noradrenaline)‐containing autonomic nerve fibers were observed amongst smooth muscle cells of the vesico‐urethra junction; other than for perivascular nerve plexuses. Noradrenergic fibers were absent from biopsy samples of other regions. Juxtamural, acetylcholinesterase‐positive neurones were present in some samples, and a proportion of these cell bodies were closely related to noradrenergic nerve terminal regions. These findings are discussed in relation to those of other workers who have examined the innervation of the mammalian lower urinary tract.
Fine structure of the spermatic granuloma of the rat vas deferens following vasectomy
Authors: Kennedy Samuel W. , Heidger Paul M. 
Published: February 2005

AbstractLight and electron microscopic studies of the spermatic granuloma of the rat vas deferens which arises post‐vasectomy were undertaken to determine if such granulomata exhibit the morphological features typical of granulomata described in other systems. Vasectomy was performed utilizing a technique of division and fulguration, and tissues for study were fixed in situ by means of vascular perfusion at 2, 4, or 12 weeks post‐operatively. Invariably, a spermatic granuloma formed at the testicular end of the sectioned vas by 2 weeks post‐vasectomy. At the time periods studied, the granulomata exhibited a cellular wall of variable thickness and complexity surrounding a central mass of sperm. This wall consistently was divisible into (1) a loosely arranged interface region populated by neutrophils and other spermiophagic cells, and (2) a more peripheral, compactly arranged region populated primarily by macrophages and epithelioid cells. Multinucleate giant cells were especially prominent in the later stages studied. Peripheral to the wall, but without an intervening basal lamina, lay a loosely organized, highly vascular connective tissue region containing only sparse collagen and few fibrocytes. Here, too, macrophages, epithelioid cells, lymphocytes, and plasma cells were noted in abundance. A well‐developed capsule composed of fibrocytes, collagenous bundles, and smooth muscle cells surrounded the granuloma. Such features conform to those descriptions in the literature of chronic granulomatous inflammation.
Characterization of intensely fluorescent cells in the liver of the rat I. Histochemistry and 48/80‐induced degranulation
Authors: Dimlich Ruth V. W. , Reilly Frank D. , Meineke Howard A. , McCuskey Robert S. 
Published: February 2005

AbstractThe nature of the intensely fluorescent cells (IFC) in the livers of male Sprague‐Dawley rats was evaluated using histochemical and pharmacological techniques. The number and distribution of IFC in portal areas were quantified using some of these techniques. Cells which were metachromatic as well as fluorescent for serotonin, histamine, and heparin were observed in the connective tissue of the portal space, hilus, and capsule of the liver. Cells with the characteristics of chromaffin, enterochromaffin, or enterochromaffin‐like cells were not seen in these locations. Intravenous administration of compound 48/80, a known mast cell degranulator, caused a significant decrease in the number of fluorescent and metachromatic cells in the portal areas of the liver. However, no significant difference was found in the number of cells counted in either the 48/80 or control groups when comparing the data from several histochemical methods. These results provided evidence that: (1) IFC demonstrate both fluorescence and metachromasia and, therefore, are mast cells, (2) compound 48/80 causes a comparable decrease in the number of serotonin and histamine fluorescent as well as metachromatic cells, indicating concomitant rather than differential release of serotonin, histamine, heparin, and/or other metachromatic substances, and (3) each of the three histochemical methods appears of equivalent sensitivity when used to study the effect of various factors (i.e., 48/80) on the release of endogenous substances from IFC. The results of this study indicate that the effects of 48/80 in vivo might be mediated through the release of various vasoactive substances from these IFC (mast cells).
Development of the cornea during fetal life: Comparison of corneal and bulbar diameter
Authors: Harayama Kenji , Amemiya Tsugio , Nishimura Hideo 
Published: February 2005

AbstractTwo hundred twenty undamaged human fetuses without external malformations were supplied by the human embryo and fetus collection at the Department of Anatomy, Kyoto University. The diameters of the cornea and eyeball were measured by slide calipers under a stereomicroscope.The various diameters of the eyeball showed a parallel, linear increase from the 12th to the 28th week of menstrual age. Corneal diameters appeared to increase in parallel with the eyeball as a whole until the 16th week of menstrual age; later on their rate of growth declined.The corneal limbus could be recognized macroscopically at the 17th week of menstrual age and was distinctly seen from the 20th week of menstrual age. The corneal curve at the limbus began to be a little convex at the 21st week of menstrual age and became distinctly convex from the 23rd week. The cornea was transparent from the 12th to the 28th week of menstrual age. The sclera lost its transparency from the 21st week.It is significant that during fetal life the sagittal diameter of the eyeball is shorter than the vertical and transverse diameters.
Freeze‐fracture study of rat ventral prostate: Secretory mechanisms in the epithelial cell
Authors: Kachar Bechara , Da Silva Pedro Pinto 
Published: February 2005

AbstractMembrane events during apocrine and merocrine secretion of rat ventral prostate epithelial cells were analyzed by freeze‐fracture. Early morpho‐logical manifestation of both secretory modes involves focal clearance of microvilli characterized by their progressive inclination and attenuation over the apical membrane. Merocrine secretion includes invasion of the apical microfilament web by the secretory vesicle and clearance of membrane particles at the site of its interaction with the apical plasmalemma. During apocrine secretion, a portion of the plasma membrane cleared of microvilli projects into the lumen. Growth of this projection is accompanied by a progressive, but partial, clearing of membrane particles and results in the formation of a large bleb containing dilated endoplasmic reticulum cisternae. Completion of the process involves “degeneration” of the bleb and its release by constriction of a neck and, possibly, fusion of vesicular or tubular structures. Swelling and blebbing of microvilli are shown to be preparation artifacts.
Scanning electron microscopy of an elastic fiber network which forms the internal elastic lamina in canine saphenous vein
Authors: Crissman Robert S. , Ross James N. , Davis Terrance 
Published: February 2005

AbstractScanning electron microscopy (SEM) was used to study the arrangement of elastic fibers in the canine saphenous vein as the basis for further studies of veins used in by‐pass grafting operations. The elastic fiber arrangement in distended and non‐distended veins was examined in both immersion‐fixed and perfusion‐fixed vessels. Transmission electron microscope (TEM) observation of the SEM samples confirmed the identity of these fibrillar structures as elastic fibers. In addition, specific stains for elastic fibers (Verhoeff's iron hematoxylin and orcein) were used. The elastic fibers forming the internal elastic lamina were arranged in a fishnet‐like pattern. Large‐diameter fibers, running longitudinally along the vascular wall, were interconnected by smaller oblique fibers. Together the fibers formed an elastic cylindrical network between the endothelium and the smooth muscle cells. The thicker longitudinal fibers were the same diameter in distended and non‐distended veins. By contrast, the oblique fibers were thinner and more complexly branched in distended veins. The architecture of the elastic fiber network contributes to vascular flexibility and allows circumferential distension. The interconnecting oblique fibers presumably serve to distribute internal pressure equally around the venous wall.
Fine structure of the rostral pars distalis of the adenohypophysis of the killifish, Fundulus heteroclitus, in fresh and salt water
Authors: Betchaku Teiichi , Douglas W. W. 
Published: February 2005

AbstractA fine structural study has confirmed earlier light microscopic observations indicating that prolactin cells are the only endocrine cells present in the main body of the rostral pars distalis of the adenohypophysis of Fundulus heteroclitus, a killifish common in New England coastal waters. Some ACTH cells occurred in thin plaques applied to the neurohypophysial trunk in the posterior part of the region. In freshwater‐adapted specimens the volume occupied by the prolactin cell mass was larger than in saltwater‐adapted specimens and contained larger prolactin cells. A paucity of contact specializations between the parenchymal cells may facilitate their spatial rearrangement as the prolactin cell population varies with changes in ambient salinity. Many fine neurohypophysial processes penetrated deeply into the rostral pars distalis and contained Type B (aminergic) nerve fibers believed to modulate prolactin secretion. These fibers ended mainly on the basement membrane that separates the neurohypophysial processes from the parenchyma. Synaptic contacts on prolactin cells were not observed but no prolactin cell appeared to be more than five cell widths from such a nerve terminal. The results emphasize the usefulness of the rostral pars distalis of this easily obtained and maintained teleost for studies of prolactin cell function.
Investigations on the turnover of adrenocortical mitochondria. XIV. A correlated biochemical and stereological study of the effects of chronic treatment with ethidium bromide on the growth maintenance of the rat zona fasciculata mitochondria
Authors: Nussdorfer Gastone G. , Mazzocchi Giuseppina , Rebuffat Piera , Zucchi Sandro C. , Robba Claudia 
Published: February 2005

AbstractThe effects of ethidium bromide (EB) on rat adrenocortical cells were investigated by biochemical and stereological methods. It was found that a treatment with ip. injections of 10 μg/gm of EB every 12 hours induced a persistent inhibition of the incorporation of 3H‐thymidine and 3H‐uridine into the mitochondrial fraction, but not into the nuclear fraction. Chronic treatment with this dose of EB provoked in zona fasciculata cells of rats treated with maintenance doses of ACTH a noticeable decrease in the volume of the mitochondrial compartment (due to the decrease both in the number per cell and in the average volume of the organelles) and in the surface area of the mitochondrial cristae. These findings lend support to the hypothesis that the mechanism underlying the ACTH‐induced maintenance of the growth of adrenocortical mitochondria involves mitochondrial DNA reduplication and transcription.
Ontogeny of the pituitary‐thyroid system in fetal rats: Observations on the fetal thyroid after maternal treatment with goitrogen
Authors: Eguchi Yasunobu , Fukiishi Yonetaka , Hasegawa Yasuhiko 
Published: February 2005

AbstractThe critical time of onset of the reciprocal relationship between the pituitary and the thyroid in fetal rats was assessed by the appearance of goiters in fetuses after maternal treatment with goitrogen, propylthiouracil (PTU), on various days of gestation. The assessment was based on changes in the weight and histology of the fetal thyroids. The day following overnight mating was regarded as day 1 of gestation. Pregnant rats were treated with 40 mg PTU each day for two days and autopsied on the third day. The various experimental periods were days 16–18, 17–19, 18–20, 19–21, and 20–22. PTU given to pregnant rats on days 16 and 17 did not cause any change in the fetal thyroids. PTU given on days 17 and 18 caused only a slight increase of fetal “thyroid weight/body weight” ratio. In all other experimental periods (days 18–20, 19–21, and 20–22), PTU induced conspicuous goiters in fetuses, which was reflected by an increased weight of thyroids, an increased height of follicular cells, and a decreased amount of colloid stored in follicles. The results suggest that in fetal rats, the reciprocal relationship between the pituitary and the thyroid is established on approximately days 19–20 of gestation.
The sensory innervation of primate eyelid
Authors: Halata Zdenek , Munger Bryce L. 
Published: February 2005

AbstractThe skin of primate eyelid contains three distinctive sensory nerve terminals. Small down hairs have a collar of lanceolate terminals that are formed by ramifications of the six to eight myelinated afferent fibers. Extensions of Schwann‐cell cytoplasm form masses of cytoplasmic lamellae associated with these terminals. Every large hair or eyelash contains a large pilo‐Ruffini as well as sparse lanceolate terminals. The eyelash Ruffini corpuscle resembles those of monkey facial guard hairs, sinus hairs, and joint capsules of the cat and pigeon. Sparse lanceolate terminals present between the Ruffini corpuscle and eyelash external root sheath resemble those of vellus hairs. On rare occasion Merkel cells are present in the hair follicle external root sheath above the sebaceous gland. Merkel touch spots, or Tastscheiben, are located between contiguous eyelashes as small rete pegs containing several Merkel cell‐neurite complexes innervated by one or two myelinated afferent fibers. The function of this array of sensory terminals is presumed to represent an extensive mechanism of protection for the cornea and globe. On the basis of studies reported to date we can conclude that the Ruffini corpuscles (and related receptors) are the ubiquitous mechanoreceptors of cutaneous and musculoskeletal systems in birds as well as mammals.