bluuebunny/crossref_metadata_2025 huggingface dataset:
Increase in Cholesterol in the Apical Plasma Membrane of Uterine Epithelial Cells during Early Pregnancy in the Rat
Authors: Murphy C.R. , Dwarte D.M.
Published: July 2008

Freeze-fracture cytochemistry with the cholesterol-binding antibiotic filipin has been used to examine the plasma membrane of uterine epithelial cells at different stages of pregnancy in the rat. We find many more filipin -induced lesions on day 6 of pregnancy than on day 1 and suggest that this indicates a higher cholesterol content at this time. Since day 6 of pregnancy is the time at which blastocysts implant in the rat uterus, we consider the possible significance of an increased cholesterol content for implantation.
Immunocytochemistry on the Localization of 5-Hydroxytryptamine in Monkey and Rabbit Taste Buds
Authors: Fujimoto Sunao , Ueda Hiroshi , Kagawa Hirohiko
Published: July 2008

Immuno-electron microscopy with the protein A-gold method demonstrated immunoreactive gold particles against 5-hydroxytryptamine localized in cored vesicles aggregating around presynaptic terminals of the gustatory cells in monkey and rabbit taste buds. The positive reactions were also found in the intragemmal and sub-epithelial nerve fibers. The role of these cored vesicles in taste transduction is still uncertain but the data strongly suggest that they may participate in a serotonergic modulation of a cholinergic synaptic transmission from the gustatory cells to the nerve endings.
Morphometric Analysis of Cartilage Canals in the Developing Mouse Epiphysis
Authors: Cole Ada A. , Wezeman Frederick H.
Published: July 2008

Cartilage canal development in the distal femoral epiphysis of 5- to 7-day-old mice can be divided into three stages as previously described [Cole and Wezeman, Am. J. Anat. 174: 119–129, 1985]. Using this model, a morphometric analysis of canal volume density at the three stages of development was performed and provided evidence that canal formation significantly exceeds epiphyseal growth. These data are consistent with initial canal formation by invasion rather than by inclusion.
Comparative Studies of the Dorsal Surface of the Tongue in Three Mammalian Species by Scanning Electron Microscopy
Authors: Iwasaki Shin-ichi , Miyata Ken , Kobayashi Kan
Published: July 2008

Comparative features of the dorsal tongue epithelia in musk shrews, mongooses and rats were described. The shapes of the filiform papillae were different in each of the species. The distribution pattern of filiform papillae was similar both in the musk shrews and mongoose, in that the form of filiform papillae changed gradually from the lingual apex to the posterior part of the lingual body. By contrast, the different types of filiform papillae were distributed on definite areas of the dorsal lingual surface in the rat. Microridges on the interpapillar surface in the musk shrew and mongoose presented a clear outline, but those of the rat were not so distinct. In all species, the upper surface of filiform papillae did not show any distinct microridges.
Morphometric Electron-Microscopic Investigation of the Neuronal Processes in the Neurohypophysis in Water-Loaded, Normal and Water-Deprived Rats
Authors: Andersen Lars
Published: July 2008

The neuronal processes in the neurohypophysis of the rat were analyzed by electron microscopy and morphometry after the secretion of antidiuretic hormone had been fully suppressed by water load. The water was supplied through a catheter inserted in the external jugular vein for 1.5, 2.5 and 24 h, respectively. The neurohypophysis was also examined in normal rats and rats that had been water-deprived for 72 h. The rats were fixed through chronically implanted catheters, so that at the time of fixation the animal was uninfluenced by anaesthesia and surgery. Water load increased the density of the neurosecretory granules in the endings in the zone nearest the basal lamina of the pericapillary space. The interpretation of this is that water load fills up the readily releasable pool of the neurosecretory granules. Water-deprival increased the density of dispersed microvesicles in the endings, especially in the zone near the basal lamina, and it is suggested that the dispersed microvesicles are involved in membrane recapture.
Unusual Combination of Anomalies of Lumbar Nerve Roots
Authors: Goffin Jan , Plets Christian
Published: July 2008

Different types of anomalies of the lumbosacral nerve roots are documented in the literature. However, combinations of anomalies in one single person appear to occur very seldom. This report describes a unique combination of adjacent, conjoined and anastomosed lumbosacral nerve roots.
Ultrastructure of the Pineal Gland of the Tropical Bat Rousettus leschenaulti
Authors: Chang Nada , Bhatnagar Kunwar P. , Tseng Michael T. , Karim K.B.
Published: July 2008

The ultrastructure of the pineal organ was studied in the tropical megachiropteran Rousettus leschenaulti. The pineal lies deep beneath the hemispheres adjacent to the third ventricle and is traversed by the habenular commissure anteriorly. Its parenchyma consists of a uniform population of light and occasional dark pinealocytes which appear to differ only in the degree of cytoplasmic staining. Pinealocytes are characterized by well developed Golgi bodies associated with numerous small vesicles, many mitochondria and polyribosomes, and frequent subsurface cisternae. Lipid droplets and elements of smooth endoplasmic reticulum are scant. Cisternae of granular endoplasmic reticulum are occasionally dilated. A distinct feature is the abundance of clear vesicles in the pinealocyte pericapiUary terminals, which also frequently contain granular vesicles and a very large vacuole. The pineal is further characterized by the presence of a small number of glial cells and myelinated nerve fibers. A broad perivascular space investing numerous capillaries contains glial-cell and pinealocyte processes, collagen fibrils and abundant unmyelinated nerve fibers. Tortuous extensions of the perivascular space enter the pineal parenchyma where they come in close roximity to branched intercellular channels or canaliculi characterized by specialized junctions and microvilli. Differences between the pineal of the non-hibernating megachiropteran Rousettus and that of the hibernating microchiropteran bats, and structural similarities to the pineal of tropical rodents are discussed.
Experimental Study on Developing Rat Kidney after Naja haje Envenomation
Authors: El Hessy H. , Rahman Abdel , Iskander F. , Nassar A. , El Maghraby M.
Published: July 2008

In the present experiment 164 pregnant white Wistar rats were used to study the effect of Naja haje (Egyptian cobra) venom on the developing kidney. The rats were divided into 3 groups; a control group, a group receiving one LD50 of N. haje venom and the third injected with % of LD50. The injection was performed at different stages of gestation. After birth, the neonates of group I and III and embryos of group II were examined histologically, histochemically and electron-microscopically. Both lethal and sublethal doses of N. haje venom produced haemorrhages and vascular congestion of the developing kidney. The lethal dose had degenerative effects on the podocytes and endothelium. Tubular damage appeared mainly as mitochondrial degeneration and bud-like extension, protrusions of cytoplasm and vacuolization. The succinic dehydrogenase enzyme showed decreased activity. The sublethal dose had an effect on the glomerular basement membrane in the form of splitting, increased mesangial cells and matrix, mitochondrial degeneration and fusion of podocyte processes. Tubulization of the parietal epithelium, vacuolization of the proximal tubules, mitochondrial degeneration and apical budding were evident.
Formation and Regression of Capillary Sprouts in Corpora lutea of Immature Superstimulated Golden Hamsters
Authors: Spanel-Borowski Katharina , Mayerhofer Artur
Published: July 2008

The ultrastructure of developing and regressing capillary sprouts was studied in corpora lutea of immature golden hamsters between days 4 and 7 after the application of serum gonadotrophin of pregnant mares (PMSG). Horseradish peroxidase (HRP), an endothelial tracer, was localized by ultrahistochemistry. The vascular permeability of HRP was quantified by an enzyme assay in ovarian homogenates. Sprouting endothelial cells looked activated. They showed micropinocytotic vesicles in a high endothelium surrounded by basal laminae. Early capillary growth was at its maximum on day 4 after PMSG. Advanced capillary growth was seen on days 4 and 5 after PMSG. The vascular lumina were formed by dilatation of the interendothelial space. Regression of capillary sprouts started on day 5, was most intense on day 6 and negligible on day 7. Two processes of regression were observed. One led to a complete destruction, the other to an incomplete one. Vascular permeability decreased between days 5 and 6 after PMSG. It is concluded that the corpus luteum can be viewed as a physiological model of angiogenesis.
Electron-Microscopic Cytochemistry of the Catecholaminergic Innervation of ACTH-Containing Neurons in the Rat Hypothalamic Arcuate Nucleus
Authors: Kozasa K. , Nakai Y.
Published: July 2008

The synaptic relationship between catecholamine terminals and adrenocorticotropic hormone (ACTH)-containing neurons in the arcuate nucleus (AN) of the rat hypothalamus was investigated by electron microscopy, using ACTH immunocytochemistry combined with autoradiography after 3H-dopamine (3H-DA) injection or 5-hydroxydopamine (5-OHDA) uptake in the same tissue section. ACTH-like (ACTH-LI) immunoreactive nerve cell bodies and fibers received synaptic inputs by axon terminals labeled with 3H-DA or 5-OHDA in the AN. This suggests that catecholaminergic neurons, at least DA- and 5-OHDA-containing neurons, may play an important role in the regulation of ACTH secretion or other functions of ACTH neurons via synapses in the AN of the rat hypothalamus.
Papilla palatina, Nasopalatine Duct and Taste Buds of Young and Adult Rats
Authors: Settembrini Beatriz P.
Published: July 2008

The morphology of the papilla palatina, the nasopalatine ducts and the taste buds situated within these ducts was studied in pups and adult rats using light and electron microscopy. During development, the papilla palatina grew in width and depth, becoming a protuberance in weanlings and adults. The nasopalatine ducts enlarged and two folds of the lateral walls of the ducts differentiated, reducing the width of the tubes in the region of the oral openings. Taste buds appeared postnatally. Light, dark, and perigemmal cells were found in all stages studied, but light cells were scarce up to 8 days of age. The taste pore appeared between 11 and 13 days of age; it lacked electron-dense material of cellular origin. Synaptic-like images could be found only in relation to dark cells. The papilla palatina, the nasopalatine ducts and the taste buds were fully developed by the 3rd week of life.
Quantitative Electron-Microscopic Analysis of the in vivo Effects of Tetrahydrocannabinol on Rat Preovulatory Follicles
Authors: Zoller Lawrence C. , Buono Joanne Quealy , Carr Kenneth , Ninke Elizabeth , Vegso Kara
Published: July 2008

The ultrastructural composition of 4 regions of rat preovulatory follicles was examined using stereological techniques following an intraperitoneal injection of tetrahydrocannabinol (THC), once each day, for 3 days prior to sacrifice on proestrus. Control rats were injected with solvent alone. Changes in nuclear, mitochondrial, lipid droplet and dense-body volume density were measured. No differences in volume density were noted in the theca or antral region of the membrana granulosa. Compared to controls, the mitochondrial volume density decreased in the peripheral region and the corona radiata. The volume density of lipid droplets decreased in the peripheral region. These changes, and their relationship to the roles of these regions in follicular steroidogenesis, are discussed.
Microscopical and Electrophysiological Studies on the Healing-Over of Striated Fibers of Cremaster Muscle of the Guinea Pig
Authors: Echeverría Olga M. , Ninomiya Jesús G. , Vázquez-Nin Gerardo H.
Published: July 2008

In previous works it has been shown that the striated fibers of the cremaster muscle undergo a calcium-dependent healing-over reaction after transection and that the fibers of the diaphragm under the same conditions do not recover. In the present work striated fibers of the cremaster and diaphragm are studied, using electrophysiological techniques, light and electron microscopy, 15, 30, 45 and 6.0 min after transection in an attempt to clarify the process leading to the recovery of the fibers of the cremaster muscle. The recording of membrane potentials at different times after the lesion in the immediate vicinity of the cut end demonstrates that the new diffusion barrier is formed at the damaged surface. Light microscopy of fibers of cremaster transected in vitro indicates the existence of a rapid process preventing the outflow of particulate constituents of the cytoplasm 1 min after the lesion. Electron microscopy shows that this hindrance is due to a compact disposition of filaments derived from altered myofibrils near the cut end. This filamentary plug does not exist in the diaphragm. Cell membrane closing is a slow phenomenon which is completed between 30 and 60 min after the lesion in different fibers. No reconstitution of the cell membrane was found in the fibers of the diaphragm. Rapid and slow responses are interpreted as particular cases of the surface precipitation reaction known in several cell types for more than 40 years.
Ultrastructural Tissue Morphometry of the Distribution of Extracellular Matrix Vesicles in Remodeling Rat Tibial Bone Six Days after Injury
Authors: Sela Jona , Amir David , Schwartz Zvi , Weinberg Haim
Published: July 2008

A study of the distribution of extracellular matrix vesicles on the 6th day of bone healing was performed by methods of transmission electron microscopy combined with computerized morphometry. The vesicles were detected on the electron micrographs and grouped according to their diameters, distance from the calcified front and type. The different types were selected as follows: (a) vesicles with electron-lucent contents, i.e. ‘empty’; (b) vesicles with amorphous electron-opaque contents, i.e., ‘amorphous’; (c) vesicles containing crystalline depositions, i.e., ‘crystal’, and (d) vesicles containing crystalline structures with ruptured membranes, i.e. ‘rupture’. Most of the vesicles were concentrated between diameters of 0.02 and 0.22 µm. Most of the vesicles were found within a distance of less than 3 µm from the calcified front. The vesicles were distributed according to their types: ‘empty’, ‘amorphous’, ‘crystal’ and ‘rupture’ in 14, 39, 34 and 13%, respectively. The diameters of the ‘crystal’ and ‘rupture’ vesicles were significantly larger than those of the ‘empty’ and ‘amorphous’ types. The sequence of distances from the calcified front was recorded as follows: ‘rupture’, ‘crystal’, ‘amorphous’ and ‘empty’, the ‘rupture’ type being the closest to the front. The results of the present study confirm the accepted hypothesis on calcification via extracellular matrix vesicles. It is thought that the cell secretes ‘empty’ vesicles that accumulate amorphous Ca and P to form a hydroxyl-apatite crystal. This is followed by rupture of the vesicular membrane. The propagation of the process is accompanied by increase in the vesicular diameter and its approximation to the calcifying front.
Effects of Long-Term Intake of a Fine-Grained Diet on the Mouse Masseter Muscle
Authors: Maeda Norihiko , Kawasaki Tsuyoshi , Osawa Koichi , Yamamoto Yoshiro , Sumida Hosaku , Masuda Tamuro , Kumegawa Masayoshi
Published: July 2008

Muscle fibers of the masseter muscle of mice which had been fed a fine-grained diet for various periods were studied histochemically and morphometrically. The diameters of both extrafusal and intrafusal muscle fibers decreased with time in mice fed a fine-grained diet, compared with those of control mice. In animals maintained on the special diet for 160 days after weaning at the 20th postnatal day, the effects of the diet on the diameter of muscle spindles were severe, and the diameter of each type of red and white fibers was significantly smaller than those of control animals. But a significant difference was not recognized in the diameter of intermediate fibers between control and treated mice. Unexpectedly, white fibers having a smaller diameter than red fibers were observed in diet-fed mice after the 180th postnatal day, although white fibers having such small diameter were not detectable in control animals. Succinic dehydrogenase activities were decreased in both extrafusal and intrafusal fibers of experimental animals. Moreover, muscle spindles with no annulospiral endings were increased in number in mice fed the diet for 130 and 160 days after weaning, although those spindles also increased in control animals. The diameters of outer capsules and primary endings were also significantly decreased in the animals kept on the diet for a long time. These effects of the finegrained diet on the mouse masseter muscle became severer with time.
The Elastic Fibre System in the Veins of the Human Lower Oesophagus
Authors: de Carvalho Ferraz
Published: July 2008

The elastic, elaunin and oxytalan fibres in the tunica mucosa and tela submucosa of veins of the human lower oesophagus were studied in 30 necropsy and biopsy specimens using appropriate histological and ultrastructural methodologies. Elaunin fibres predominate in the veins endowed with muscle cells. Scattered oxytalan and elastic fibres were also observed, the latter being more numerous at the vein periphery. No noteworthy fibre arrangement was encountered in veins lacking muscle cells. Those fibres disposed around the veins were considered to belong to the connective tissue of the tunica mucosa and tela submucosa in which they are embedded. The veins of the lower oesophagus seem to be of low elasticity, which may be related to a blockage mechanism described for the gastro-oesophageal blood stream in cases of portal hypertension.
Skeletal Relationships in the Human Embryonic Foot Based on Three-Dimensional Reconstructions
Authors: McKee Patricia R. , Bagnall Keith M.
Published: July 2008

Several investigators have reported that the relationships of the embryonic skeletal elements are strikingly different from the adult condition.The present study examined these relationships during the final four stages of the embryonic period (i.e., stages 20–23). Six serially sectioned human embryos, ranging from 21.7 to 34.0 mm crown-rump length, approximately 51–57 postovulatory days, were studied. Three-dimensional reconstruction, involving wax plate and transparency models, was used to recreate the skeletal elements of the embryonic foot, representing each of the four developmental stages by a separate reconstruction. These models provided three different views of the embryonic foot because they were developed from specimens that were sectioned in three different sectional planes. The serial sections of the other two embryos were subsequently studied by microscopic examination. For each of the six embryos, the skeletal relationships were determined, paying particular attention to the arrangement in the hind-foot. These observations were compared with skeletal material of the adult foot which represented the end point of the developmental continuum. In contrast with much of the previous literature the skeletal relationships of the embryonic hindfoot were found to be similar to the adult condition: the fibula projected further distally than the tibia; there was no evidence that the tip of the fibular malleolus was in contact with the calcaneus; and most importantly, the calcaneus was situated below the talus, not beside it as reported by other investigators.
Evonymus europaeus Agglutinin as a Marker of Endothelial Cells in the Human
Authors: Roussel F. , Tayot J.
Published: July 2008

Vascular endothelial cells were marked with Evonymus europaeus agglutinin (EEA) in the major organs of 6 subjects to reveal the anatomical distribution of positive elements in the human after fixation in paraformalde-hydelysine-periodate and embedding in paraffin. EEA may be used as a marker of human adult vascular endothelium in the same way as Ulex europaeus Agglutinin 1, revealing the same positive endothelial and epithelial territories. The intensity of labeling was constant in a given subject of the B blood group. In Aor 0 individuals the cerebral endothelium showed a much lower reactivity than the cardiac endothelium.This lectin, equally active in higher mammals, offers the unique advantage of direct comparison between species.
Topography, Architecture and Structure of the Plexus submucosus internus (Meissner) of the Porcine Small Intestine in Scanning Electron Microscopy
Authors: Scheuermann Dietrich W. , Stach Werner , Timmermans Jean-Pierre
Published: July 2008

Scanning electron microscopy of whole-mount preparations of the tela submucosa in the porcine small intestine, examined after trypsin digestion, fixation and HC1 hydrolysis, visualized a clear differentiation ofthe submucosal plexuses, i.e., the plexus submucosus internus (Meissner) and the plexus submucosus externus (Schabadasch). The distinctive features refer to the topography, number, size and shape of the ganglia and the number and diameter of the nerve strands. The plexus of Meissner is closely apposed to the external surface of the lamina muscularis mucosae by the enveloping connective tissue and by connecting strands penetrating the lamina muscularis mucosae. Three distinctive subdivisions of connecting strands can be identified. Since the glial cells covering the ganglia and connecting strands have been preserved, neither individual neuronal cells nor axons can be observed.
Histology of the Normal and Retained Equine Testis
Authors: Arighi M. , Singh A. , Bosu W.T.K. , Horney F.D.
Published: July 2008

Abdominal, inguinal and scrotal testes of horses were examined grossly and by light microscopy. An average of 1.5, 2.3 and 4.6 layers of spermatogenic cells, and mean seminiferous tubule diameters of approximately 66.2, 83.6 and 146.6 µm in the abdominal, inguinal and scrotal testes, respectively, were recorded.The interstitial spaces and the number of interstitial cells (of Leydig) seemed to be increased while spermatogenesis appeared to be arrested in the retained testes. Early spermatocytes were the most mature stages of the spermatogenic cells in the retained testes. An extensive vacuolation of spermatogenic cells was evident in these testes.The changes may result due to a high temperature of the abdominal environment in concert with the altered production of androgens.
Autonomic Nerve Terminals in Relation to Contractile and Non-Contractile Structures in the Conduit Coronary Artery of the Dog
Authors: Kristek František , Gerová Mária
Published: July 2008

The ramus interventricularis anterior (RIA), its first- and second-order branch were prepared for EM (perfused with glutaraldehyde under pressure, or simply fixed with KMn04). No nerve fibres were found in the tunica media of either of the three consecutive segments. In the tunica adventitia axons with varicosities were found at a distance from the tunica media of 0.5–15 µm (about 50% 0.5–4.5 µm) in the RIA, 0.4–12 µm (about 50% 0.5–3.4µm) in the first-order branch and 0.3–6.0 µm (about 50% 0.3–2.3 µm) in the second-order branch. Varicosities contain small, dense-cored vesicles (35–60 nm) and large, dense-cored vesicles (70–90 nm, exceptionally up to 120 nm); the other type contains small, clear vesicles (35–60 nm) and few large, dense-cored vesicles (70–90 nm). The remarkably large distance between the nerve terminals and smooth muscle cells fits well with the small range of sympathetic control of the conduit coronary artery. Close apposition of nerve terminals to fibroblasts (30–200 nm) was revealed in all three consecutive coronary portions. Moreover, terminal axons often lose the Schwann cell cover on the ablumínal site and face the fibroblast.
Cocaine: Long-Term Administration Depletes Cardiac Enzymes in the Rat
Authors: Trulson Michael E. , Epps Lisa R. , Joe John C.
Published: July 2008

Arterioles and myocytes of the cardiac ventricle were examined histochemically to determine their metabolic profiles in normal rats and in rats treated either acutely or chronically with cocaine. Following long-term, but not acute, cocaine administration, enzymes involved in both aerobic and anaerobic metabolism as well as in hexose-monophosphate shunt were greatly decreased.These data suggest that long-term usage of cocaine leads to severely impaired coronary metabolism.
Morphometry and Ultrastructure of the Squirrel Monkey (Saimii sciureus)Vestibular Nerve
Authors: Fermin Cesar D. , Igarashi Makoto
Published: July 2008

Vestibular nerves of squirrel monkeys (Saimiri sciureus) embedded in plastics and epoxies were examined with light microscopy (LM) and transmission electron microscopy (TEM) and computerized measures were obtained and analyzed statistically. An average of 12,412 perikarya and 12,005 myelinated nerve fibers was obtained. Approximately 0.7% of the perikarya appeared unmyelinated under LM. About 500 unmyelinated fibers were counted. The cross-sectional area of 1,864 perikarya was 200–650 µm2. The cross-sectional area of 1,346 nerve fibers was 3–11 µm2 for the axoplasm and 11–12 µm2 for the myelin sheath of the same fiber. Myelin thickness was directly proportional to the axoplasm cross-sectional area of the nerve fibers. The cross-sectional area of central axons and peripheral dendrites differed significantly (p < 0.001). The initial segments of peripheral dendrites were usually smaller, but longer than the initial segments of the central axons. Both initial segments increased in diameter after the first node of Ran-vier. Schmidt-Lantermann incisures were more abundant in thick and heavily myelinated fibers than in thin and lightly myelinated fibers. Larger perikarya usually had larger fibers and vice versa, within the first 100–200 µm from the first node of Ranvier. No major ultrastructural differences were found between myelinated and unmyelinated perikarya, except at the hillock region.The Nissl substance was preferentially located in the peripheral cytoplasm.
A Morphologic and Histochemical Study of the Mesentery in the Guinea Pig
Authors: Junqueira L.C.U. , Joazeiro P.P. , Toledo O.M.S. , Montes G.S.
Published: July 2008

The guinea pig mesentery is a uniform, continuous, thin (18 µm) sheet of connective tissue covered by a single layer of flattened mesothelial cells on both surfaces. Tight and gap junctions provide for cell-to-cell adhesion among mesothelial cells. These cells possess numerous micropinocytotic vesicles; a conspicuous basal lamina separates the mesothelium from the underlying connective tissue. Most of the material found between the two serous coverings consisted of a three-dimensional meshwork of abundant collagenous fibers intermingled with a sparse net of very thin (0.4 µm) elastic fibers. Two distinct populations of collagen fibrils are segregated into different compartments of the mesentery. One population is formed of thick (56 nm) fibrils which associate to form closely packed fibers. The second population, composed of loosely arranged thin (38 nm) fibrils which do not become assembled into fibers, is found underlying the basal lamina that separates the mesothelium from the connective tissue.These observations strongly suggest that the mesentery contains both collagens type I and type III. The guinea pig mesentery contains 6.8 mg of sulfated glycosaminoglycans/g dry weight. Most of these glycosaminoglycans (78%) were identified as dermatan sulfate, whilst the rest (22%) corresponded to heparan sulfate.
Further Characterization of the Chondroprogenitor Zone in Mandibular Condyles of Suckling Mice
Authors: Livne Erella , Oliver Constance , Silbermann Michael
Published: July 2008

In the neonatal mouse the mandibular condyle serves as an important growth center for the developing mandible. The youngest cells in this organ are the chondroprogenitor cells that are the source for new differentiating chondroblasts. The present study provides new data concerning the fine structure and cytochemical characteristics of the cartilage precursor cells as seen in suckling mice. The condylar chondroprogenitor cells normally reveal a mesenchyme-like appearance with multiple, elongated cell processes that enable close contact between neighboring cells. These cells also exhibit a variety of pinocytotic vesicles, coated pits and appear to be actively involved in the internalization of a fluid-phase marker horseradish peroxidase. Further, the progenitor cells were found to contain trimetaphosphatase reaction products within lysosomal bodies and alkaline phosphatase reactivity along their plasma membrane. Precipitates of calcium complexes in the form of calcium pyroantimonate could be demonstrated in association with the plasmalemmma of the cells as well as with the extracellular collagen fibrils. Matrix granules, representing cartilage proteoglycans, became a distinct feature following staining with ruthenium red and were found to be in close contact with the extracellular collagen fibrils and with the plasmalemma. Hence, in addition to their active role in cell proliferation, the progenitor cells are also involved in the synthesis and secretion of major extracellular macromolecules such as collagen and proteoglycans.
Histologie, histochimie et innervation comparées des fibres musculaires striées du muscle pectoralis major et du muscle supracoracoideus chez les oiseaux
Authors: Boesiger Berthe
Published: July 2008

The morphology of the pectoralis major muscle and the supracoracoideus muscle was compared in three Galliformes and five Passeriformes, in relation to partial behavorial characteristics. In all species, two fibre types are observed. The frequencies of these fibres are different, especially between Galliformes and Passeriformes, but also between Coturnix and other Galliformes. All fibres show phasic innervation. A relation of the extent between synaptic gutters and muscle activity is suggested.
Somatostatin-Containing and Other Endocrine Cells in the Pancreas of the Spectacled Caiman
Authors: Rhoten William B.
Published: July 2008

Light-microscopic immunocytochemistry was used to localize 4 major pancreatic hormones in the pancreas of the spectacled caiman, Caiman fuscus. Somatostatin, insulin, glucagon and pancreatic polypeptide were localized by the peroxidase-antiperoxidase complex technique. A relatively large population of somatostatin-containing D cells was present. The D cells were nearly as numerous as the insulin-containing B cells and glucagon-containing A cells which were the most common cell types. All three cell types were commonly intermingled with one another in endocrine cell areas. Pancreatic polypeptide-reactive F cells were absent from some regions of the pancreas, but where present were related to other endocrine cell types. Functional properties of the pancreatic endocrine cells in this anatomical variant remain to be determined.
Innervation of the Dermatomes in the Neck of the Mouse
Authors: Bogusch G.
Published: July 2008

The dorsal rami of the cervical and thoracic spinal nerves were investigated using both the in situ chohnesterase staining technique and chohnesterase staining on serial sections of plastic-embedded embryos. In most cases only the dorsal rami of the 2nd to 5th cervical spinal nerve possess cutaneous branches.The area innervated by the cutaneous branch of the dorsal ramus of the 5th spinal nerve borders on an area innervated by the cutaneaous branch of the dorsal ramus of the 1st thoracic spinal nerve. The dorsal rami of the cervical spinal nerves 6–8 show no cutaneous branches. Therefore the gap in the series of the dorsal cutaneous branches is due only to the middle part of the nerves of the brachial plexus, which range from the 5th cervical nerve to the 1st thoracic nerve.
Expression of ‘Visceral’ Cytokeratin and Ultrastructural Findings in Solid Cell Nests of the Thyroid
Authors: Harach Rubén , Wasenius Veli-Matti
Published: July 2008

Solid cell nests of the thyroid display histological features that resemble squamous epithelium. In the present study we investigated whether these ultimobranchial nests express a renal tubular cell cytokeratin which is found to be widely distributed in epithelia but does not appear in squamous tissue. All 17 solid cell nests studied, in contrast to squamous epithelium lining an intrathyroid thyroglossal cyst, stained positively for this intermediate filament. These findings, together with the gland-like features shown ultrastructurally by these ultimobranchial remnants, further support the view that solid cell nests of the thyroid should not be regarded as a kind of intrathyroid squamous inclusion. In addition, they were electron-microscopically comparable to mammalian ultimobranchial tissue.
Catecholaminergic Innervation of Neurons Containing Corticotropin-Releasing Factor in the Paraventricular Nucleus of the Rat Hypothalamus
Authors: Kítazawa Shigetaka , Shioda Seiji , Nakai Yasumitsu
Published: July 2008

Catecholaminergic synaptic input to neurons containing corticotropin-releasing factor (CRF) in the parvocellular portion of the paraventricular nucleus (PVN) in the rat hypothalamus was observed. The experimental techniques used combine autoradiography after 3H-noradrenaline ( H-NA) injection or uptake of 5-hydroxy-dopamine (5-OHDA) with immunocytochemistry using CRF antiserum. CRF-like immunoreactive cell bodies and fibers in the PVN received synaptic inputs from the axon terminals in which a selective accumulation of 3H-NA or 5-OHDA was found. This finding suggests that the secretion of CRF neurons may be regulated via synapses by catecholaminergic neurons.
Cortical Microvasculature of the Feline Kidney
Authors: Marais James
Published: July 2008

Scanning electron microscopy of corrosion casts was used to study the ultrastructural morphology of the microcirculation in the feline kidney. The technique used enabled us to examine the renal microvasculature by obtaining stable and consistent replicas of the vasculature. Corrosion casts were evaluated at three different levels, namely subcapsular, midcortical and the corticomedullary junction. The interlobular arteries, given off by the arcuate arteries, coursed through the cortex in a radial fashion and afferent arterioles were given off at varying intervals. Large afferent arterioles formed the glomerular capillary lobules which consisted of very tortuous capillaries. Smaller-diameter efferent arterioles were formed at the vascular pole and ran in the opposite direction to the afferent arteriole. The peritubular plexuses were seen as interconnecting capillaries at both the subcapsular, midcortical and corticomedullary junction. Numerous efferent arterioles, derived from the corticomedullary glomeruli, were seen as large, radiating vessels running towards the renal papilla.
Computer-Aided Three-Dimensional Graphic Reconstructions in a Radiological and Anatomical Setting
Authors: Poelmann R.E. , Verbout A.J.
Published: July 2008

With the aid of a relatively simple computer system three-dimensional graphic reconstruction models have been prepared.The procedure was applied in anatomy on a fixed embryonic specimen and in radiology on living subjects by using computed tomography scans.The results are useful for embryological research as well as for clinical evaluation.
Gross and Histological Characterization of Endometrial Tissues from SLA Miniature Pigs with Cystic Endometrial Hyperplasia
Authors: Lipetz K.J. , Richardson M.E. , Ivey K.W. , Dickey J.F. , Diehl J.R. , Stuart L.D.
Published: July 2008

Cystic endometrial hyperplasia (CEH) is a uterine disorder characterized by the formation of large numbers of cysts in the endometrium. The purpose of this study was to examine and characterize cell types in the endometrium associated with the cysts and uterine glands. No apparent histological differences between CEH-involved and normal uterine columnar epithelium were found. Endometrial glands in CEH-involved and normal uteri were lined with simple or ciliated columnar epithelial cells and surrounded by lamellar connective tissue.The cyst epithelium appeared to be stretched obliquely and compressed so that both the cells and nuclei were horizontally oriented relative to the cyst lumen and were surrounded by lamellar connective tissue. Electron microgaphs revealed an abnormally high number of mitochondria in the cystic cells as compared to normal glandular cells. In conclusion, CEH is characterized by the formation of cysts which develop from the uterine glandular tissue. Epithelial cells lining the glands appeared to be distorted, possibly in response to internal pressure from increased volume due to high metabolic activity, and/or no uterine luminal opening.
Appearance of Immunoreactive Endocrine Cells during the Development of the Rat Pancreas, with Special Reference to Polypeptide-Secreting Cells
Authors: Gómez Dumm César L. , Galeano Ana María , Genoro Susana , Gagliardino Juan José
Published: July 2008

The chronological appearance of PP cells in fetal pancreatic islets was studied using specific anti-PP serum and the direct peroxidase method. The presence of A and B cells was also studied, using the same immunocytochemical technique, as a reference pattern related to data previously reported. Our data confirm that the A cell is the earliest endocrine cell type, appearing on the 12th day of gestation, followed by B cells (14th day) and later on by PP cells (19th day). Primitive islets were identified in the pancreas after the 15th day. However, the spatial cell disposition observed in the adult islet was only recognized at the 20th day of gestation. The data reported provide the necessary information to establish the complete chronology in the rat fetus. Consequently, the development of pancreatic islets in the rat fetus could be employed as a useful model to study the existence of factors that control the sequential appearance of endocrine cells and the possible changes occurring in the islets of animals with genetic diabetes during the fetal period.
Distribution of Elastic System Fibers in the Peripheral Nerves of Mammals
Authors: Ferreira, Jr. J.M.C. , Caldini E.G. , Montes G.S.
Published: July 2008

Various nerves of 6 representative species of mammals (including the human) were studied by the comparative association of the selective staining methods of light microscopy with the ultrastructural observation after tannic acid-glutaraldehyde fixation, which provided a reliable means of characterizing the different elastic system fibers. Although mature elastic fibers are not present in nerves, elastic-related fibers are frequently observed: oxytalan fibers are found mainly in the endoneurium, whereas elaunin fibers predominate in the epineurium. These fibers are longitudinally disposed, in a parallel orientation to the axons. The fact that these findings were consistently observed in the nerves of all species studied argues strongly in favor of the existence of a uniform structural pattern of distribution of elastic system fibers in nerves as a general phenomenon in mammals.
Distribution of Motoneurones Innervating Extraocular Muscles in the Brain of the Marmoset (Callithrix jacchus)
Authors: Clarke Robert J. , Aléssío Maria-Luisa , Pessoa Valdir F.
Published: July 2008

Extraocular muscle motoneurones were localised in the oculomotor nucleus (ON), trochlear nucleus (TN) and abducens nucleus (AN) in the marmoset brain using the horseradish peroxidase (HRP) retrograde labelling technique. HRP pellets injected into individual extraocular muscles revealed one or more groups of labelled neurones occupying discrete loci within these nuclei. Relatively little overlap of motoneurone pools was observed, except in the case of the inferior oblique and superior rectus muscles. Injections of HRP into the medial rectus muscle revealed three separate populations of labelled cells in the ipsilateral ON. Motoneurones innervating the inferior rectus muscle were mainly localised in the lateral somatic cell column of the ipsilateral ON. A second smaller grouping was observed in the medial longitudinal fasciculus.The inferior oblique muscle motoneurones were localised in the ipsilateral medial somatic cell column intermingled with motoneurones supplying the superior rectus muscle of the opposite eye. The superior oblique muscle motoneurones occupied the entire TN and the lateral rectus muscle motoneurones the AN. It was concluded that the organisation of nuclei and subnuclei responsible for controlling the extraocular muscles in the marmoset is broadly similar to that of other primates.
Paraganglia of the Superior Laryngeal Nerve of the Rat
Authors: Domeij Siw , Carlsöö Bengt , Dahlqvist Åke , Hellström Sten
Published: July 2008

Paraganglia were consistently found at the bifurcation of the superior laryngeal nerve of the rat. Ultrastructurally the paraganglionic cells resembled the type I and type II cells of the carotid body. The dense-cored vesiculated type I cell was found most frequently, whereas the type II cell represented 10–25% of the cell population. The volume density of the dense-cored vesicles was found to be 3.5 ± 0.5, which is about half as much as that found in the recurrent laryngeal nerve and about twice of that found in the carotid body. Atotal of 24,634 dense-cored vesicles were measured, and the mean diameter was calculated to be 113.8 ± 4.9 nm. Based on the median vesicle profile diameter, only one type of dense-cored vesicle cell was found.
Étude quantitative du cœur chez deux embryons humains jumeaux de 14 mmV-C (stade 18)
Authors: Mandarim-de-Lacerda Carlos A. , Passos Marco A.R.F. , Sampaio Francisco J B.
Published: July 2008

Two hearts of human twin embryos at 14 mm C-R (stage 18) were studied by means of light microscopy and quantitative methods. The serial sections of the embryos, 5 µm thick, were projected by using a microprojector for the measurement of the cardiac diameters and cardiac profile areas.The calculated heart volumes were 8.34 and 8.45 mm3, respectively. Cardiac volume is more accurate than linear.measurement to establish quantitative development of the heart. It can also be considered an accessory index for embryonic classification.
Ultrastructural Analysis of the Mouse Nasal Septum
Authors: Lessner Ulrike , Rehn Bernd
Published: July 2008

Respiratory cilia of mice from 3 days prior to birth till 21 days after birth were examined by freeze-fracture preparations for the determination of the frequency and size of the intramembranous particles (IMPs). Dependent on the age of the animals different numbers and sizes of IMPs were found. A significant drop in total number of IMPs in all diameter classes was most evident from the 19th day of gestation to the 20th day (1 day prior to birth), followed by a marked rise between embryonal day 20 and the 1st postnatal day. The results were discussed with regard to morphological and functional changes in the respiratory system prior to and after birth.
Quantitative Study of Hepatocytes from Minipigs and Minipig Fetuses Exposed to Ethanol in vivo
Authors: Rømert Paul , Matthiessen Martin E.
Published: July 2008

The effect of ethanol on hepatocytes from pregnant minipigs and their half-term fetuses was studied with the aid of morphometric methods. In the pregnant minipigs the hepatocytes of the ethanol-treated animals showed a significant increase in the volume density of mitochondria, autophagic vacuoles, Golgi complexes and smooth endoplasmic reticulum, and a significant decrease of glycogen. In the half-term fetuses the hepatocytes of ethanol-exposed animals showed no significant change in the volume density of mitochondria, peroxisomes, autophagic vacuoles, Golgi complexes, smooth endoplasmic reticulum or glycogen, and no significant change in the surface density of granular endoplasmic cisternae. The present investigation indicates that in the maternal hepatocyte certain cytoplasmic components are quantitatively changed by ethanol, whereas the volume and surface densities of identitical components in the fetal hepatocyte are unaffected. The significance of these results is discussed.
Ultrastructure of the Myocardium in Dogs with Induced Jaundice
Authors: Ludatschef Ruth M. , Binah Ofer , Bomzon Arieh , Better Ori S. , Lichtig Chaim
Published: July 2008

Morphological aspects of the myocardium in dogs with experimentally induced jaundice were assessed ultrastructurally. Obstructive jaundice was produced by chronic bile-duct ligation and by choledochocaval anastomosis. The left ventricular myocardium and the papillary muscle were used. Statistical analysis of sarcomere length and of mitochondrial density showed no significant differences between jaundiced and sham-operated dogs. Qualitative evaluation of the mitochondria, the intercalated disc and other sarcoplasmic constituents revealed no damage to the jaundiced dogs.
Morphologic Study of Ventricular Trabeculation in the Embryonic Chick Heart
Authors: Icardo José M. , Fernandez-Terán A.
Published: July 2008

This paper presents a morphologic study of ventricular trabeculation in chick embryo hearts between days 2 and 5 of incubation. Trabeculation appears to be the expression of three closely interrelated events: the formation of endocardial outgrowths that eventually invade the myocardium; the development of large intercellular spaces between the myocytes, and the decrease in thickness of the cardiac jelly. Endocardial cells present morphologic differences between trabeculated and nontrabeculated areas of the ventricular region. The elongation of the endocardial cells in the endocardial outgrowths and the presence of mitoses suggest that the endocardium grows out by means of an increase in cell number and by redistribution and elongation of the preexisting endocardial cells. The intercellular spaces of the myocardium appear filled with abundant extracellular material. It is suggested that the continuous synthesis of extracellular material by the myocytes may increase the hydrostatic pressure within the myocardium, inducing the formation and the enlargement of these intercellular spaces. The development and later rupture of endocardium-covered cords is described here. These cords are made up of a core of cardiac jelly material revested by endocardium. The cords may be engaged in the removal of substantial amounts of cardiac jelly during the formation of the trabeculae.
Filiform Papillae of Human, Rat and Swine Tongue
Authors: Kullaa-Mikkonen A. , Hynynen M. , Hyvönen P.
Published: July 2008

In order to study the structure of filiform papillae (FP), tissue specimens were taken from the anterior part of the tongues of 8 humans, 8 rats and 8 swine. The formalin-fixed samples were processed routinely for scanning electron microscopy (SEM) and light microscopy. With SEM, FP of human tongue contained 5–12 hairs which were covered with a massive plaque of micro-organisms. FP of rat tongue, on the other hand, contained one papillary projection with smooth surface structure. Colonization of micro-organisms was seen on the anterior part of the body of FP, but not on the hairs. In the cross-section of FP of the rat tongue, the cells of the papilla were close to each other and no micro-organisms were seen within the papillae. On the contrary, the spaces between the squamous epithelial cells of the hairs of human FP contained numerous micro-organisms. The structure of FP of the swine tongue resembled that of the rat tongue. The hairs were smooth and some micro-organisms were seen on the cell surface of the inter-papillary areas. The structure of FP is discussed from the standpoint of different keratinizatioñ and colonization of micro-organisms.