bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphometry of synaptic ultrastructure using equidensitometry
Authors: Nolan Terence , Jones D. Gareth 
Published: February 2005

AbstractElectron micrographs of synapses stained with an ethanolic solution of phosphotungstic acid have been subjected to equidensitometric analysis by the recently developed Agfacontour Professional film. Subtle variations in the staining of presynaptic dense projections and postsynaptic structures have been detected. Morphometry of these micrographs has been facilitated by this technique which is rapid and obviates the need for expensive and complex electronic equipment.
Morphology of the nasal cavities and associated structures in Artibeus jamaicensis and Myotis lucifugus
Authors: Bhatnagar Kunwar P. , Kallen Frank C. 
Published: February 2005

AbstractAnatomical differences in olfactory structures point to a more highly developed olfactory sense in the frugivorous bat Artibeus jamaicensis than in the insectivorous bat Myotis lucifugus. Artibeus' nostrils show greater potential for differential control of nasal airstreams. Its nasal cavities, in contrast to Myotis, are clearly demarcated into olfactory and respiratory portions. Both species have seven turbinals, but of the five ethmoturbinals, Artibeus has four endoturbinals and one ectoturbinal whereas Myotis has three and two, respectively. The configuration and histology of the more complex turbinals of Artibeus indicates a greater surface area of olfactory epithelium. The nasal epithelia are thicker in Artibeus. Olfactory receptors appear similar in both species but the thickness and composition of the olfactory epithelium in Artibeus suggests the presence of about twice as many receptors per unit area. This is also reflected in the relative prominence of olfactory nerve bundles. From these and other bulbar relationships we conclude that the proportion of fila olfactoria to large mitral cells, as reflected by the olfactory bulb glomeruli, is some function of a fundamental 2:1 relationship. Nasal glands, with flaps covering two of their more prominent ducts, and blood vessels are more pronounced in Artibeus. This presumably correlates with the nasal type of phonation exhibited by this bat as well as a greater ability to condition air per se. Nasopalatine ducts exist in both species but only Artibeus has a vomeronasal organ. A diffuse ganglion accompanies the organ; some of its neurons are associated with the unmyelinated vomeronasal nerve, whereas others are intraepithelial. The vomeronasal nerve terminates in a prominent accessory olfactory bulb.
Coexistence of dyads and triads in an adult striated muscle
Authors: Wong Y. C. , Hwang J. C. 
Published: February 2005

AbstractElectron microscopic studies have revealed the presence of both dyads and triads in the accessory muscle of the walking leg of the horseshoe crab Tachypleus gigas. The dyads and triads are present in approximately equal numbers. The evolutionary significance of the coexistence of dyads and triads in such an ancient animal is discussed.
Quantitative electron microscopic autoradiography of in vivo incorporation of 3H‐choline, 3H‐leucine, 3H‐acetate and 3H‐galactose in non‐ciliated bronchiolar (Clara) cells of mice
Authors: Petrik Peter , Collet André J. 
Published: February 2005

AbstractThe participation of Clara cells in the formation of alveolar surfactant and their general metabolism were studied in mice by quantitative autoradiography under electron microscopy after in vivo incorporation of four precursors: 3H‐choline, 3H‐leucine, 3H‐acetate and 3H‐galactose.Tritiated choline, a specific precursor of the dipalmitoyl‐phosphatidylcholine‐active fraction of the surfactant, is not incorporated into Clara cells. In contrast, 3H‐acetate is first incorporated actively into the endoplasmic reticulum and Golgi apparatus of these cells and, subsequently, in its secretory granules. It is suggested that acetate follows the general metabolism of the cell and/or is transformed into cholesterol. Tritiated leucine is incorporated into the secretory granules, although part of it remains more permanently in the cells. Tritiated galactose is actively incorporated, passes through the Golgi apparatus and eventually appears in the secretory granules.These results suggest that the Clara cell does not synthetize the tensio‐active fraction of the lining layer, as does pneumocyte II, but participates in the synthesis and secretion of proteins, glucides and possibly the cholesterol belonging to the hypophase.
Regeneration of the ureter and repair of the oviduct in the adult newt Notophthalmus viridescens
Authors: Scadding Steven R. , Liversage Richard A. 
Published: February 2005

AbstractThe responses of the oviduct and the male ureter to transection were studied histologically. The ureter regenerates by the formation of a blastema, then the development of a bridge of cells between the cut ends, and finally by restoration of the lumen. Seven out of 12 cases fixed 30 to 40 days after transection had reconstituted the lumen and four of the remaining five cases had the two ends joined and would likely have regenerated if they had not been fixed. In contrast, the oviducts did not appear to have any regenerative capacity; only two out of the 17 cases fixed 31 to 41 days after transection exhibited some reconstitution. The transected oviducts did not form a blastema or give any evidence of cellular dedifferentiation.
Ultrastructure of the mouse superior cervical ganglion, with particular reference to the pre‐ and postganglionic elements covering the soma of its principal neurons
Authors: Yokota Reiko , Yamauchi Akio 
Published: February 2005

AbstractElectron microscopy of superior cervical ganglia of the mouse shows both pre‐ and postganglionic elements impinging upon the soma of principal neurons. The preganglionic cholinergic axon terminals are estimated to cover about 0.7% of the total surface area of the neuronal soma and are characterized by dense packing of synaptic vesicles which remain unchanged after the administration of 5‐hydroxydopamine. Postganglionic elements are estimated to cover about 1.8% of the total surface of the neuronal soma. In many cases they contain small granular vesicles (with or without agranular reticulum), and are considered to be represented in part by vesiculated segments of the dendrite and in part by recurrent axon collaterals of the principal neuron. These postganglionic elements usually make puncta adhaerentes, but occasionally an efferent synapse, on the soma of principal neurons in the ganglion. Evidence is presented which suggests that the soma, in turn, is capable of influencing the perisomal, postganglionic elements through a somatic efferent synapse.
Increased orbital volume after periodic intrabulbar injections of silicone in growing rabbits
Authors: Sarnat Bernard G. , Shanedling Philip D. 
Published: February 2005

AbstractThe intent of this experiment was to determine whether with an increase in ocular mass there would be an increase in orbital volume. Eighteen, four‐week old, 220 to 420 gm Dutch rabbits were used. In 12 animals silicone was injected into one eye but not the opposite one. No silicone was injected into the eyes of six untreated rabbits. In a ten week period the total amount of ten silicone injections into each treated eye ranged from 1.2 to 1.6 ml. After each rabbit was euthanatized, elastic rubber base imprints were made of both cleaned orbits to determine the volumes. In the untreated animals the differences between the right and left orbital volumes ranged from — 0.1 to 0.2 ml (— 2.4 to 4.7%). The mean of the differences was not statistically significant. When the eyes were injected with silicone, the differences in orbital volumes between the injected and non‐injected sides ranged from 0.6 to 0 ml (14.6 to 0%). The mean of the differences was 0.3 ml which is statistically significant. It was concluded that periodic intrabulbar injections of silicone in the growing rabbit significantly increased orbital volume.
Some observations on the fine structure of the epidermal‐dermal junction in the skin of the frog tadpole, Rana rugosa
Authors: Nakao Taisuke 
Published: February 2005

AbstractSpecial lamellated bodies, 400 to 700 Å in diameter, are observed in the adepidermal space at the epidermal‐dermal junction of the skin of the frog tadpole, Rana rugosa. Each stained lamella is about 20 Å thick and separated from adjacent lamellae by spacings of 20 to 30 Å. The lamellated bodies are demonstrated in specimens prepared with phosphotungstic acid (PTA)‐containing fixatives, but are not revealed in specimens fixed with ordinary aldehyde fixatives which lack PTA. They are sometimes observed within the cytoplasm of basal epidermal cells, suggesting their epidermal origin. Far less frequently, comparable structures are present outside the sarcolemma of skeletal muscle fibers. Three kinds of anchoring structures are observed at the epidermal‐dermal junction: anchoring filaments, anchoring fibrils, and anchoring fibers. The anchoring filaments are observed in the adepidermal space connecting hemidesmosomes to the basal lamina. They are 200 to 230 Å in diameter and have no banding pattern. Anchoring fibrils, 210 to 250 Å thick and unbanded, are present in the upper one‐third of the collagenous lamellae. Fibrils do not have a banding pattern. Direct continuity between anchoring fibrils and anchoring filaments is suggested. Anchoring fibers, about 170 mμ, thick, occur less frequently. They are composed of laterally aggregated finer fibrils which show no clear bandings. Their distal ends join with the basal lamina and they extend proximally deep into the collagenous lamellae.
Distribution and configuration of surface myoneural junctions in the frog sartorius muscle
Authors: Carpenter Duncan B. 
Published: February 2005

AbstractThe Karnovsky cholinesterase stain was used to map the positions of the myoneural junctions distributed over the inner surface of three frog sartorius muscles. In each preparation end‐plates were seen to occur in clusters, predominantly associated with fine myelinated nerve fibers in proximity to the larger nerve branches. No myoneural junctions were observed in the extreme proximal or distal regions of the muscles. Although more junctions were found in the regions proximal to the point of nerve entry into the sartorius muscle, terminals were more consistent in their location in areas distal to this point. End‐plate configurations varied appreciably in length, branching and complexity, but the majority of the terminal nerve processes extended parallel to the long axis of the muscle fibers.
Freeze‐fracture appearance of the capillary endothelium in the cerebral cortex of mouse brain
Authors: Connell C. J. , Mercer K. L. 
Published: February 2005

AbstractExtensive tight junctions are located between overlaps of plasma membranes of capillary endothelial cells. Micropinocytotic vesicles are few in number and are seen as invaginations on the A face and as protrusions on the B face. The freeze‐fracture appearance of these cells is consistent with their thin section appearance and their role as the site of the blood‐brain barrier.
Proliferative response to the skin‐sensitizing contact agent dinitrofluorobenzene in lymph nodes in mice
Authors: Schneider Gary B. 
Published: February 2005

AbstractWhen dinitrofluorobenzene (DNFB) is applied to the skin in mice, it induces a state of delayed hypersensitivity. During the three days following the application of this contact agent, lymphoblasts accumulate in the diffuse cortex of the lymph node draining the area of sensitization. This accumulation of blast cells – referred to as a blastogenic response – appears to be part of the induction phase of delayed hypersensitivity.This is an investigation into the origin of the cells of the blastogenic response. There is evidence from other studies that lymphocytes immigrate to the lymph nodes draining a site of sensitization. This paper provides complementary evidence that cellular proliferation in the diffuse cortex of the sensitized lymph node is another source for the accumulation of blast cells. This proliferation has been studied by counting mitotic figures, and by autoradiography after giving 3H‐thymidine in order to determine the number of blast cells undergoing DNA synthesis and the duration of the various phases of the cellular reproductive cycle.The results show a high degree of correlation between mitotic figures and blast cells in the diffuse cortex of the sensitized lymph nodes, consistent with a population of dividing blast cells. Approximately 80 percent of the blast cells were in the DNA‐synthetic phase of the reproductive cycle at the peak of the blastogenic response, and the cells were dividing with approximately an eight hour generation time.These results can be interpreted to indicate that the cells of the blastogenic response, although accumulating initially by immigration to the draining lymph node, become a homogeneous, nondifferentiating population of blast cells, all proliferating at near maximal rate to provide the great numbers of blast cells seen three days after application of the sensitizing agent.
Modifications, some cytochemical properties and transport of intralysosomal membranes
Authors: Vidić Branislav 
Published: February 2005

AbstractThe structural alterations of intralysosomal membranes were investigated in the rat lateral nasal and maxillary glands. In addition to conventional electron microscopical procedures, the following cytochemical reactions were applied: acid phosphatase, ruthenium red, phosphotungstic acid, and silver tetraphenylporphine sulfonate. Two forms of intralysosomal membranes were described, the myelin‐like figure and the aligned membranes. The former variety occurred most often in the lysosome and occasionally in some other organelles (e.g., secretory granule, multivesicular body, Golgi apparatus). Some figures were observed in the process of extrusion from the lysosome into the cellular interior. Furthermore, there were indications of the release by the cell of these membranes either into the lumen or toward the basal lamina. The acid phosphatase test revealed an association of the enzyme with the myelinated membrane in the lysosomal medium, in various cellular locations, and in the cellular environment. The possible importance of some interstitial cells in the transport of these membranes from the acinar base outward was noted. The other form, referred to as aligned membranes, occurred only as individual couples within the lysosomal interior. The formation of multilamellar complexes by further cross‐binding of membranous pairs was not observed. They displayed a focal occurrence of globules of apparently lipid material and a continuity with the already existing lipid droplets. Both types of altered membranes stained with phosphotungstic acid at pH 1.5, although they did not stain with silver tetraphenylporphine sulfonate. Most findings suggested that the two membranous varieties represented different patterns in membrane autodigestion.
Prenatal development of the vomer in normal and cleft palate mice
Authors: Sakizlioglu Isik , Frommer Jack , Shiere Frederic R. 
Published: February 2005

AbstractIn mouse fetuses with cleft palate induced by cortisone, the shape of the entire nasal septal structure was slightly altered, due possibly to the lack of palatal shelf contact, but no significant changes occurred in the basic development of the vomer. Nor was any evidence found to show a direct or indirect influence of the vomer on structures involved in the formation of a cleft palate.
“Native” striated collagen produced by chick notochordal epithelial cells in vitro
Authors: Carlson Edward C. , Upson Rosalyn H. 
Published: February 2005

AbstractWe report here the observation of striated collagen produced by notochordal cells in vitro. Fibrils with collagen‐like striations were seen in large intercellular spaces following three days of incubation in vitro. Surprisingly, similar fibrils and large sheets (1,500 Å wide) of collagen showing a 510 Å periodicity were seen in notochordal tissues cultured in the presence of β‐aminopropionitrile (BAPN), a known inhibitor of cross‐linking in tropocollagen. These observations support the view that the notochord should be considered one of several embryonic epithelial tissues known to secrete collagen.
Lethocerus flight muscle paramyosin: Antibody localization and electrophoretic studies
Authors: Levine Rhea J. C. , Dewey Maynard M. , Elfvin Myra , Walcott Benjamin 
Published: February 2005

AbstractAntibody specific for Limulus paramyosin stains the A bands of Lethocerus flight muscle sarcomeres. SDS‐polyacrylamide gels of both Limulus telson and Lethocerus flight myofibrillar preparations show bands with mobility similar to that of purified Limulus paramyosin.
Origin, differentiation and renewal of the four main epithelial cell types in the mouse small intestine IV. Paneth cells
Authors: Cheng Hazel 
Published: February 2005

AbstractThe origin, differentiation and fate of Paneth cells in adult mouse small intestine was examined by electron microscopic radioautography at various times after a single injection of 3H‐thymidine.The Paneth cell population consists of 23% young Paneth cells with granules less than 2 μm in diameter, 63% mature Paneth cells with granules 2–3 μm in diameter, and 14% old Paneth cells with granules greater than 3 μm in diameter.Light and electron microscopic radioautography confirms that typical Paneth cells are not labeled 1 hour after 3H‐thymidine injection and, therefore, are not capable of proliferation. However, labeled cells with a few small Paneth cell granules are first observed 12 hours after an injection. Except for the presence of granules, these cells are indistinguishable from the highly proliferative crypt‐base columnar cells. It is, therefore, suspected that Paneth cells are derived from crypt‐base columnar cells.With time after injection, differentiation proceeds: stacks of rough endoplasmic reticulum cisternae appear, the granules become progressively more numerous and larger, and the nucleus acquires an irregular shape. Labeled mature Paneth cells are observed by five days after injection.Unlike the other three cell types, Paneth cells do not migrate up to the villus epithelium and thus are not lost through the extrusion zone. Instead they undergo degeneration in the crypt‐base and are eventually phagocytosed by an adjacent crypt‐base columnar cell.
Ontogeny of human fetal lymph nodes
Authors: Bailey Raymond P. , Weiss Leon 
Published: February 2005

AbstractDeveloping lymph nodes from 30 human embryos and fetuses with crown‐rump lengths (CRL) of 18 mm (5.6 wk) to 245 mm (26 wk) were examined by light microscopy. The nodes were embedded in araldite, and the sections examined were approximately 1 μ in thickness. The development of nodes was divided into three stages: 1. the lymphatic plexus and connective tissue invagination (30 mm to 67 mm CRL); 2. the early fetal lymph node (43 mm to 95 mm CRL); and 3. the late fetal lymph node (CRL greater than 75 mm). The lymphatic plexus was formed by connective tissue invaginations and bridges which divided a lymph sac into a meshwork of channels and spaces. Connective tissue invaginations were endothelially‐lined and were surrounded by lymphatic space. Reticular cells, macrophages, and blood vessels were found in these invaginations. Early fetal lymph nodes were formed from invaginations when the cellular density and lymphocyte content increased. The lymphatic space surrounding the early node was the developing subcapsular sinus. With further development the early node became packed with lymphocytes, increasing the cellular density and size of the node. The connective tissue surrounding the subcapsular sinus condensed to form the capsule. Afferent lymphatic vessels pierced the capsule. Capillaries, veins, postcapillary venules, and occasional arteries were found in early and late nodes.
Morphological and histochemical studies on a PAS‐positive granular leukocyte in blood and connective tissues of Catostomus commersonnii Lacépède (Teleostei:Pisces)
Authors: Barber D. Louise , Westermann Jean E. Mills 
Published: February 2005

AbstractThis study was undertaken to identify an ubiquitous granular leukocyte found in Catostomus commersonnii Lacépède. The cell contains large, numerous, strongly PAS‐positive cytoplasmic granules, an eccentric nucleus and prominent, persistent juxtanuclear space. It develops in the hemopoietic tissue of the kidney, and mature cells are found not only in kidney and peripheral blood but also in areas of connective tissue where mast cells are usually located. Electron microscopy confirms the presence of a large Golgi apparatus, unlamellated cytoplasmic granules and extensive rough‐surfaced endoplasmic reticulum.Histochemical studies show that the cytoplasmic granules are alcianophobic, non‐metachromatic and unstained by acridine orange. Histamine is detectable spectrophotometrically in kidney tissue, but the PAS‐positive granular leukocyte does not consistently degranulate after treatment with histamine liberator 48/80.The authors suggest that while the PAS‐positive granular leukocyte is not identical with classical basophils/mast cells, which are absent in C. commersonnii, it may represent an evolutionary precursor of these cells.
Comparative anatomical study of the hyoid apparatus in selected primates
Authors: Hilloowala R. A. 
Published: February 2005

AbstractThis paper embodies a comparative study of the hyoid apparatus in six species of primates. There is a direct correlation between a predominantly herbivorous diet and an increase in the relative size of the basihyal (the body) of the hyoid bone.The basihyal has a deep “cup‐shaped” concavity in the howler but is very flat in the marmoset. The baboon, rhesus and capuchin fall in between these two extremes. The configuration and size of the basihyal are directly proportional to the presence or absence and the size of the median air‐sacs. Of the species studied, the posterior cornu (thyrohyal) of the hyoid bone is present in all the species, but the hypohyal is present only in the baboon, rhesus and capuchin. A true styloid process is found only in the baboon, although the rhesus has a bony spicule. All except the howler have a stylomandibular ligament from which arise the stylohyoid, stylopharyngeus and styloglossus muscles. The anterior bellies of the two sides of the digastric muscle are truly united only in the marmoset, but are approximated in the baboon and rhesus. The stylohyoid muscle at its insertion into the basihyal is pierced by the intermediate tendon of the digastric muscle in the rhesus and capuchin, but not in the howler and baboon. In the marmoset the presence of a stylohyoid muscle is variable.
Tubules and filaments in satellite cells and axons of sensory neurons
Authors: Peach Roy 
Published: February 2005

AbstractSatellite cells covering the axon hillock region and initial axon process of the neurons of rat and mouse trigeminal ganglia contained numerous parallel microtubules and microfilaments. These were oriented circumferentially to axonal neurofilaments and neurotubules. The latter were sometimes grouped in fascicles. The results suggest a specialized role for the supporting cell in this region and that fascicles of neurotubules are not related to action potential initiation.