bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neuro‐epithelial bodies (neuroreceptor or Secretory Organs?) in Human Infant Bronchial and Bronchiolar Epithelium
Authors: Lauweryns Joseph M. , Peuskens Joseph C. 
Published: February 2005

AbstractTissue sections of 15 lungs from human infants were taken immediately after death. In each case, routine staining methods and Jabonero's silver impregnation, modified by Van Campenhout, were performed. Cathecholamines were traced according to Falck's method. Each of these techniques revealed in the bronchial and bronchiolar mucosa spherical to ovoid groups of cells, which are distinct, from the surrounding epithelium by their light optical and their histochemical properties and which have been named “Neuroepithelial Bodies.”The Neuroepithelial Body bulges into the corium and is built up of cells with a clear cytoplasm and a rounded nucleus. Its apical part protrudes into the bronchial and bronchiolar lumen mostly above the level of the ciliated cell lining and consists of small non‐ciliated cuboidal cells. After silver impregnation, they display a granular silver deposit, especially in the basal cells and appear to be innervated. The technique of Falck reveals a white to yellow fluorescence, especially in the basal area where also the argyrophilia is most marked.The functions of these corpuscular, argyrophilic, innervated and fluorescent bronchial and bronchiolar Neuroepithelial Bodies remain unsettled. Though a separate entity, they seem to be related to the recently reported bronchial Argyrophil, Fluorescent and Granulated AFG (peptide and amine producing?) cells. They might be involved in mucosal bronchial and bronchiolar neurosecretory processes; most probably, however, they are chemo‐, stretch‐, and/or tactile neuro‐receptor organs.
The development of the periodontium: The origin of alveolar bone
Authors: Tencate A. R. , Mills C. 
Published: February 2005

AbstractFirst molar tooth germs consisting of dental organ, dental papilla and dental follicle were dissected from one‐day old mice and transplanted subcutaneously into young adult animals of the same strain. Three to four weeks after implantation the host animals were sacrificed and the transplants harvested. The transplants were prepared for either routine histological examination or for electron microscopy. Forty tooth germs continued development with the formation of a periodontium consisting of cement, periodontal ligament and bone. Electron microscopical examination of this material demonstrated the presence of lymphocytes in association with the subcutaneous bone and thereby suggested the origin of the bone from donor tissue.
Presence of fenestrated capillaries in the skin
Authors: Takada Mitsuya , Hattori Shizuko 
Published: February 2005

AbstractCapillaries of the skin have been thought to be of a nonfenestrated type according to studies of previous investigators. However, the present study revealed that fenestrations exist in the endothelium of cutaneous vessels. Capillary fenestrations are numerous in the human finger and the mouse sole and are moderately frequent in the guinea pig sole and ear. In the skin of the human chest, however, they are rarely encountered. Sometimes, endothelial fenestrations are encountered in venules as well.
Evidence of cell damage in rat salivary glands after isoproterenol
Authors: Simson J. A. V. 
Published: February 2005

AbstractIsoproterenol, which stimulates cell replication in rat salivary gland acinar cells also produces cytoplasmic disruption in these cells, although there is apparently little resultant cell death. Evidence of cell damage includes loss of cytoplasmic density, vesiculation of endoplasmic reticulum, appearance of large lipid droplets within cells, and invasion of the epithelium by lymphoid elements.
A study of hematic barriers in peripheral nerves of albino rabbits
Authors: Aker F. David 
Published: February 2005

AbstractHematic barriers were studied in femoral and sciatic nerves and their peripheral branches in male albino rabbits by means of fluorescence microscopy and ultra‐freezing and drying technics. The fluorescent tracer used was a diaminoacridine, acriflavine neutral, which is non‐toxic at the 20 mg/kg dose administered intravenously, has a low molecular weight (259.7), and has a unique quality of chemically binding in vivo with nuclear DNA and RNA. This latter property of acriflavine neutral permitted the observation of fluorescent nuclei where the substance penetrated and no fluorescence where it did not penetrate. The interface between the two regions was identified as a locus of a hematic barrier.Three hematic barrier loci were observed in spinal nerves and their branches: (1) in the plasma membranes of the cells forming inner lamellae of the “perineurial epithelium,” (2) in the luminal face of the plasma membrane of endothelialcellsforming the wall of endoneurial capillaries, and (3) in the “perineurial epithelial” sheath which surrounds endoneurial precapillaries. These barriers appeared to be dependent on normal living physiologic processes for their proper maintenance. In addition, they were very similar to some of the hematic barriers associated with the central nervous system.
The fine structure of the monkey (Macaca) sertoli cell and its role in maintaining the blood‐testis barrier
Authors: Dym Martin 
Published: February 2005

AbstractThe monkey Sertoli cell, a tall columnar cell, extends from the basement membrane of the seminiferous epithelium to the tubule lumen. Its nucleus occupies a basal position and reveals extensive nuclear envelope infoldings. A zone of fine filaments, approximately 0.5 μ in thickness, invests the nucleus and appears to prevent other cell organelles from approaching it. The basal cytoplasm is characterized by numerous mitochondria and abundant smooth endoplasmic reticulum. Lipid droplets, 3 to 4 μ in diameter, membrane‐limited dense bodies of various shapes and densities, Golgi cisternae, scattered free ribosomes and parallel profiles of rough endoplasmic reticulum are common. The more apical portions of the cell contain longitudinally oriented microtubules and rod‐shaped mitochondria, but other organelles are rare.The seminiferous tubules of monkeys are surrounded by three to five circumferentially arranged cells that overlap each other but are separated by intercellular spaces of at least 300 to 400 Å. Tracers such as horseradish peroxidase and lanthanum nitrate injected intravascularly readily pass between the peritubular cells and enter the germinal epithelium. Within the epithelium the tracers outline the spermatogonia and early spermatocytes by permeating the surrounding intercellular spaces. Further penetration toward the tubule lumen is effectively prevented by the occluding tight junctions joining adjacent Sertoli cells. Thus, in monkeys the peritubular epithelioid cells do not impede vascularly introduced tracers from penetrating into the germinal epithelium. The only morphological component of the blood‐testis barrier in the macaque appears to be the Sertoli‐Sertoli occluding junction.
Ultrastructural morphology of the normal nasal respiratory epithelium of the mouse
Authors: Matulionis Daniel H. , Parks Harold F. 
Published: February 2005

AbstractThe nasal respiratory epithelium of the mouse has been studied at the ultrastructural level. The tissue was found to be a rather typical pseudostratified columnar ciliated epithelium, superficially different but basically similar to tracheal and bronchial epithelium in the same species, and clearly similar in most respects to that of other mammals. Four cell types were distinguished: ciliated columnar, secretory (goblet), intermediate, and basal.The ciliated cells, which exhibited typical surface cilia and microvilli, were characterized by a distinct stratification in the arrangement of subcellular components in their supranuclear cytoplasm. Beginning at the apical end and proceeding basally, the following strata were seen: an ectoplasmic region relatively free of organelles; an area rich in vesicular and tubular membrane profiles; a mitochondrial zone; a layer rich in ribosomes and polyribosomes; and a stratum of Golgi complexes.Secretory (goblet) cells were observed at various stages of secretion droplet accumulation. Cells in the earliest stage, characterized by a dense content of sER in the supranuclear cytoplasm, were similar to the “non‐ciliated” cells of the mouse's lower respiratory tract. Some of the secretory cells contained dilated cisternae of rER which were engorged with a relatively electron‐dense material. The possible significance of these inclusions is discussed.Unlike the other cell types, intermediate and basal cells displayed no features indicative of specialized function.
Studies of human adipose tissue in culture. II. Effects of insulin and of medium glucose on lipolysis and cell size
Authors: Smith Ulf , Jacobsson Bo 
Published: February 2005

AbstractExplants of human adipose tissue were maintained for one week in vitro and the effect of iodoacetate, insulin and of the medium glucose concentration on cell size determined. In the presence of iodoacetate the mean cell size remained unaltered indicating that the morphologic changes reflect the cellular rates of metabolism. Addition of insulin did not prevent a decrease in mean cell size of explants with a large initial mean offering indirect, morphologic evidence for the insulin resistance in large adipocytes. The data support our previous suggestion that the cellular insulin sensitivity is an important parameter to control adipocyte size and, hence, enlargement of the adipose tissue.
Alterations in the epithelial surface of A/Jax mouse palatal shelves prior to and during palatal fusion: A scanning electron microscopic study
Authors: Waterman Robert Earle , Ross Lawrence M. , Meller Samuel M. 
Published: February 2005

AbstractThe surfaces of palatal shelves from carefully staged A/Jax mouse embryos were examined with the scanning electron microscope prior to and during palatal fusion. No change was observed in the appearance of cells covering the oral and nasal surfaces of the shelves. A change was observed, however, in the region of presumptive fusion, and was detectable on vertical shelves just prior to transposition. This change initially involved surface cells along the future medial edge of the shelf at the level of the second to third rugae. It was characterized by a loss of distinct cellular boundaries, the appearance of intercellular gaps caused by apparent retraction of adjacent cells, and a progressive accumulation of filamentous material at the surface. These alterations spread posteriorly along the medial edge of the shelf during transposition and fusion. While it was impossible to determine the precise nature of the surface change from S.E.M. data alone, the fact that it both preceded closure and was restricted to the region of subsequent contact and fusion between the shelves suggests it may be a prerequisite for normal palatal fusion and may represent an expression of the acquisition of a potential to fuse similar to that proposed for palatal fusion in vitro.
Release and restoration of the secretory granules in the convoluted granular tubules of the rat submandibular gland
Authors: Cutler Leslie S. , Chaudhry Anand P. 
Published: February 2005

AbstractMorphological changes in the secretory cells of the convoluted granular tubules of the rat submandibular gland were studied following the stimulation of salivary secretion with pilocarpine nitrate. The mechanism of synthesis of secretory protein by these cells is controversial and this study was undertaken to help elucidate this mechanism. It was found that the cells expelled the contents of their secretory granules in the typical exocrine fashion. Shortly after secretion, increased volumes of rough endoplasmic reticulum appeared in the cytoplasm. The endoplasmic reticulum underwent a sequence of morphologic changes and disappeared from the cytoplasm as the secretory products were restored. Additionally, the Golgi complex showed changes. The results of this study indicate that the secretory cells of these tubules follow the accepted exocrine pattern of secretory production and discharge and that they synthesize exportable proteins at a rate far below that of other exocrine systems. The relationship of these findings to the observation that under non‐stimulated conditions the cytoplasm of these cells lacks some of the organelles which are normally associated with exocrine type protein production is discussed.
Quantitative analysis of the synaptogenic period in the trigeminal mesencephalic nucleus
Authors: Alley Keith E. 
Published: February 2005

AbstractThe morphogenesis of chemical synapses in the trigeminal mesencephalic nucleus of the hamster was examined in the electron microscope. The relatively small complement of synapses and the simple geometry of these neurons facilitates quantitative analyses of synaptic development. Emphasis focused on the chronology of synaptic maturation and the length of the synaptogenic period in this nucleus. Synaptic endings first appear on the soma at three or four days after birth. These early terminals form desmosome‐like junctions without any synaptic vesicles. The surface density of terminals (synapses/100 μm of perimeter) increases rapidly from 5 to 15 days when it is approximately equivalent to the adult. However, calculations that also take into account the expansion in cell surface area suggest that the actual number of terminals continues to increase as the cells grow. This indicates that these neurons may retain their synaptic capacity and continue to add new synaptic sites for a longer period than proposed for other systems. Structural characteristics of these synapses in the adult suggest they may be inhibitory in nature and thus regulate the interaction of electronically coupled clusters of neurons.
Chronological and cytological details of fertilization and early embryonic development in the domestic pig, Sus scrofa
Authors: Hunter R. H. F. 
Published: February 2005

AbstractThe sequence of cytological events from sperm penetration of the oocyte until emergence of the blastocyst from the zona pellucida was studied in 1441 eggs from 134 animals in which the time of ovulation had been controlled precisely by gonadotrophin injection. Observations were also made on the rate of egg passage through the Fallopian tubes, on the process of denudation, and on the increase in numbers of spermatozoa associated with the zona pellucida.Eggs may be penetrated and activated within three hours of mating or insemination close to the time of induced ovulation. A decondensation and swelling of the chromatin is seen very soon after incorporation of the sperm head into the vitellus, and central apposition of the pronuclei occurs three to five hours later. The male pronucleus is slightly larger than the female, and a portion of the flagellum is frequently closely associated with it until late syngamy. Cleaved embryos can be recovered within 14 to 16 hours of sperm penetration, but the two‐celled stage lasts only six to eight hours compared with 20 to 24 hours for the four‐celled stage. Embryos enter the uterus at the latter stage approximately 46 hours after ovulation. Morulae of 16 to 32 cells can occasionally be observed late on the third day of development, and blastocysts are present on the fifth day. However, the zona pellucida is not shed until the sixth day, after which the trophoblast commences the massive elongation characteristic of this ungulate blastocyst.
Cell population changes during acinus formation in the postnatal rat submandibular gland
Authors: Chang W. W. L. 
Published: February 2005

AbstractThe postnatal differentiation of acini in the submandibular glands of 2–42 day old rats given 3H‐thymidine was studied by using radioautographs prepared from Epon‐embedded, PAS and iron hematoxylin stained sections. The changes in morphology, population size and proliferative activity of various cell types in the gland were analyzed. At two days of age, rudimentary secretory units, designated as terminal tubules, were located at the end of the duct system and consisted of three cell types: (1) terminal tubule cells (30.7%) with darkly‐stained granules, (2) proacinar cells (23.6%) with large, lightly‐stained granules, and (3) acinar cells (1.6%) with PAS‐positive granules. The proacinar cells, which underwent mitosis, disappeared within the first two weeks of life. The terminal tubule cells increased in number between 2 and 14 days of age, but became less numerous thereafter and disappeared by six weeks. Concomitantly, the number of acinar cells increased linearly with age and at a much greater rate than that of intercalated duct cells. Yet the rate of proliferation of acinar cells was comparable to that of intercalated duct cells. The overall proliferative activity in the gland decreased with age, and was inversely correlated with the relative frequency of acinar cells in the gland. On the basis of above data, it is postulated that, during the formation of acini from terminal tubules, acinar cells have a dual origin: they arise from proacinar cells during the first one to two weeks and from terminal tubule cells between two and six weeks of age.
Muscle satellite cells: A validated technique for light microscopic identification and a quantitative study of changes in their population following denervation
Authors: Ontell Marcia 
Published: February 2005

AbstractA staining technique, in which basic fuchsin, methylene blue, and Azure II is applied to 0.5 μ sections of striated rat muscle embedded in epoxy resin, has given sufficient differentiation of five nuclear types found in the muscle fascicle to warrant its use as a valid method for identifying satellite cells with the light microscope. The validity of this technique was assessed by studying serial thin and thick sections of denervated rat hind limb muscles. Nuclei “typed” light microscopically were examined under the electron microscope to determine the type of cell in which they were located. This stain technique was then applied to determine the effect of denervation on the satellite cell population of the tibialis anterior and extensor digitorum longus. In control muscle of 200 gm rats, satellite cells represented 2% of the total nuclear population. Two and three weeks after denervation they accounted for 6% and 12%, respectively. In 800 gm rats, satellite cells accounted for 0.7% of the total nuclei found in the normal muscle. Denervation increased the percentage to 3% (at 2 weeks) and 5% (at 3 weeks). Paired satellite cells were infrequently observed; however, in 0.5 μ sections a significant number of satellite cells were found to be less than 0.7 μ from a myonucleus of the same fiber. A model is proposed to explain the increase in satellite cells following denervation.
Patterns of degeneration in the caudal cochlear nucleus of the cat after cochlear ablation
Authors: Kane Eileen Cohen 
Published: February 2005

AbstractStudy of the caudal cochlear nucleus of the cat confirms the cochlear origin of synaptic terminals, identified in correlated rapid Golgi and electron microscopic preparations of the octopus cell area (OCA) and the dorsal cochlear nucleus (DCN) in normal cats. Type 1 and type 2 endings on octopus cell somas and basal dendrites, as well as type 1 and type 1a endings of the outer DCN, degenerate following complete ipsilateral cochlear ablations and short survival periods (12, 24, 48, 96 hours). Two distinct patterns of synaptic degeneration occur after short survival times; “dense degeneration” occurs in type 1 endings on octopus cells and several endings of the DCN. Dense terminals that contain tightly packed, but intact vesicles, occur most frequently after a 48‐hour survival period. A second type of degeneration, called “flocculent degeneration” occurs in type 1 and type 2 endings of the OCA and in type 1 and type 1a DCN terminals. Between 12 and 48 hours after ablation, the flocculent degeneration involves a continuous breakdown of organelles. Evidence for transneuronal degeneration of octopus cells and DCN granule cells is presented.
Ultrastructural organization of the sensory fibers innervating the Golgi tendon organ
Authors: Schoultz Ture W. , Swett John E. 
Published: February 2005

AbstractThe organization of the sensory innervation of Golgi tendon organs (GTO) from E. carpi ulnaris of the cat is described. The large Ib afferent fiber gives rise to small myelinated branches which become oriented longitudinally in a neural compartment of the GTO capsule lumen. The latter give rise to smaller, unmyelinated branches which further arborize among loosely packed collagen bundles. The unmyelinated fibers form numerous varicosities and small terminal branches which have portions of the axolemma covered only by basal lamina which intervenes between the collagen bundles and the axolemma. In places, the axon's surface may lack all investments and nerve and collagen come into intimate association. The large unmyelinated branches and their varicosities have different axoplasmic characteristics compared with the small unmyelinated terminal portions. The latter contain few or no mitochondria, vesicles, neurotubules, and neurofilaments. In addition to the description of the terminals, the similarities and differences of the innervation of the GTO, compared with other mechanoreceptors, are discussed.
Epithelial cell proliferation during organogenesis of rat colon
Authors: Eastwood Gregory L. , Trier Jerry S. 
Published: February 2005

AbstractBetween the 16th to the 20th day of gestation, the mucosa of the colon of fetal rats changes from a simple tube with a tiny lumen lined by stratified epithelium to a much more complex structure with a large lumen and well‐developed crypts lined by a single layer of columnar epithelium. Autoradiographic studies with 3H‐thymidine show that cell proliferation is present throughout the stratified epithelium but becomes confined to the lower half of colonic crypts immediately on their formation. The number of epithelial cells shown to be proliferating after exposure to a single pulse of 3H‐thymidine is high during this period of organogenesis but decreases rapidly after the 20th day of gestation once the adult mucosal pattern has formed.
The postnatal growth of the rat lung II. Autoradiography
Authors: Kauffman Shirley L. , Burri Peter H. , Weibel Ewald R. 
Published: February 2005

AbstractCombined morphometric and autoradiographic methods were used to analyze the postnatal growth of rat lung from 1–21 days after birth. Each cell population had distinct growth patterns with an increase in the number of fibroblasts and capillary endothelial cells largely determining the increase in interstitial volume and capillary surface, respectively. The height of proliferation activity in mesodermally‐derived cells was concurrent with the outgrowth of secondary alveolar septa (between days 4 and 13). Analysis of the location of labeled cells on day 7 showed that the higher labeling index on septal crests could be ascribed to the proliferative activity of fibroblasts and endothelial cells.Within the alveolar epithelium only the type II alveolar cells had a detectable labeling index. Over the first week, the number of type I epithelial cells steadily increased while the number of type II cells remained constant. Subsequently the number of type II cells increased rapidly, reached a peak on day 13 and then decreased, whereas type I cells continued to increase in number. These facts led us to consider that type II epithelial cells may represent the stem cell population of alveolar epithelium. The height of proliferative activity of type II cells on day 7 coincided with the outgrowth of septal crests and was followed by the steepest increase in number of type I and II cells.Between the 10th and 21st day labeling indices rapidly declined, cell production became undetectable after day 13. Increase in alveolar and capillary surface area however continued, resulting in a thinning of the interstitial layer and of the epithelial and endothelial sheets.