bluuebunny/crossref_metadata_2025_split huggingface dataset:
Visceral anatomy of the amphisbaenia
Authors: Crook Juanita M. , Parsons Thomas S. 
Published: February 2005

AbstractStudy of the visceral anatomy of 41 specimens of amphisbaenians representing 13 genera shows that they share a very distinct structure which differs from that found in either snakes or typical lizards. The left lung is large while the right is rudimentary or absent (unique); the kidneys are freely suspended in the coelom by a mesentery (unique); the spleen is usually embedded in the anterior end of the pancreas (as in snakes); the gall bladder lies in a notch in the liver, and the kidneys lie opposite each other (as in lizards). The distinctness of this pattern supports the recognition of the Amphisbaenia as a separate suborder of the Squamata.
Carapace repair in the green crab, Carcinus maenas (L.)
Authors: Dillaman Richard M. , Roer Robert D. 
Published: February 2005

AbstractFormation of a circular hole 8–10 mm in diameter in the calcified layers of the carapace from crabs in stage C4 of the molt cycle stimulates the tissue under and adjacent to the injury to deposit a unique calcified cuticular material below the intact membranous layer. Deposition was followed for 69 days using light microscopic histology, histochemistry, and scanning electron microscopy. Quantitative analyses of CaCO3 were conducted using atomic absorption spectrophotometry and Gran titration. Spatial distribution of CaCO3 was determined with X‐radiography. A scab is formed by day two under the injury. At four days the epithelium changes from squamous to columnar and deposits a PAS‐positive layer with an irregular lamellar fine structure, followed by highly organized lamellae structurally similar to normal exocuticle. Histochemically, however, these lamellae resemble normal endocuticle. CaCO3 is evident external to the outermost lamellae by day eleven as a fused mass of aragonite granules. The lamellar region calcifies proximally from the outer surface and is amorphous CaCO3. Repair cuticle is approximately 20%CaCO3 by weight.
Intralamellar neurohemal complexes in the cerebral commissure of the leech Macrobdella decora (Say, 1824): An electron microscope study
Authors: Webb Rodney A. 
Published: February 2005

AbstractElectron microscopy of the cerebral ganglionic commissure of the leech Macrobdella decora (Say, 1824) revealed numerous neurosecretory axons terminating in the neural lamella of both the inner and outer capsules, and in the neural lamella deep within the neuropile. The proximal protions of the terminals, with an investment of glial tissue, contain either numerous large homogeneously electron dense granules, or numerous large granules of varying electron density. The distal portions, often devoid of glia, display numerous infoldings, omega profiles, and electron dense focal sites, and contain numerous neurosecretory granules, small lucent vesicles, and, occasionally, acanthosomes. Statistical analysis of the size distribution and morphology of the neurosecretory granules showed that in many individual terminals the granules are not significantly different from those seen within four groups of neurosecretory cells found in the cerebral ganglion. These terminals, because of their diffuse nature, probably represent a neurohemal complex of a primitive nature. The term “intralamellar complexes” is proposed to describe the form and location of these neurosecretory terminals.
Organogenesis of the colon in rats
Authors: Brackett Kim A. , Townsend Samuel F. 
Published: February 2005

AbstractColonic organogenesis in rats was studied using light microscopic techniques for the demonstration of mucosubstances, glycogen, and connective tissue fibers.Crypts began as intraepithelial spaces which were in continuity with the colonic lumen. The cells forming the floors of these spaces invaded the nonsulfated acid glycosaminoglycan‐rich mesenchyme as the basement membrane became discontinuous. As the diameter of the colon increased, the crypts lengthened and the lamina propria thickened until a layer of collagen and sulfated acid glycosaminoglycans formed at the bases of the crypts and the basement membrane was reestablished. The circular layer of the muscularis externa developed first, then the longitudinal layer, and finally the muscularis mucosae.Three types of mucous cells arose in these newly formed crypts. The initial epithelial cell type contained glycogen and gave rise to cells with apical coats of nonsulfated acid glycoproteins. This cell type was followed by the appearance of cells at the bases of the crypts containing nonsulfated acid glycoproteins. As the crypts lengthened, the goblet cells near the base contained nonsulfated and/or sulfated acid glycoproteins. Closer to and on the surface, the cells contained sulfated acid glycoproteins, a mixture of sulfated acid and neutral glycoproteins, or just neutral glycoproteins. Striated‐border cells appeared intermingled with the mucous cells close to the bases of the crypts and continued onto the surface.A comparison was made between regeneration following placement of a surgical lesion in adult rats and events in organogenesis of the colon.
Ultrastructural analysis of the morphology and function of the spermatheca of the pulmonate snail, Sonorella santaritana
Authors: Rogers Steffen H. , Reeder Richard L. , Shannon W. Allen 
Published: February 2005

AbstractThe ultrastructure of the spermatheca of the reproductive tract in the pulmonate snail, Sonorella santaritana, was investigated. This organ has a debris‐filled lumen and an outer wall which can be divided into three distinct layers. The cell layer adjacent to the lumen is comprised of two cell types, tall columnar epithelial cells with microvilli and cells lacking microvilli. The next layer also has two cell types, muscle cells and apparent pigment cells. The most distant layer is an adventitia of large glycogen‐containing cells. The lumen of the spermatheca contains a core of partially digested sperm and related materials.The luminal contents and the cellular morphology of this organ suggest that the spermathecal functions are both digestive and absorptive. It is proposed that excess sperm and related materials are transported to the spermatheca, digested, and the usable products are reabsorbed.
Ultrastructural study on cocoon formation in the freshwater oligochaete, Tubifex hattai
Authors: Suzutani‐Shiota Chiyo 
Published: February 2005

AbstractThe clitellar epithelium of the freshwater oligochaete, Tubifex hattai, is composed of four types of gland cells (Type I, II, III, and IV), in addition to the cells generally found in the epidermis of this worm. The possible function of these gland cells in cocoon formation was studied with the electron microscope.Type I cells discharge their secretory granules by means of compound exocytosis and provide the materials for the future cocoon membrane. Immediately after completion of the discharge from Type I cells, Type II and III cells simultaneously discharge their secretory granules by means of compound exocytosis. The secretions from Type II cells constitute a colloid in the cocoon lumen and probably cause structural modifications in the future cocoon membrane. The secretory products from Type III cells form the cocoon plug. Although the process of discharge of secretory granules from Type IV cells was not observed, the contribution of these cells to the cocoon formation, producing hoops on the outer surface of the future cocoon membrane and fixing its anterior ends on the clitellum, is inferred from a morphological comparison of the hoop and the structure of the secretory granules.
Light and electron microscopic observations on the normal structure of the vomeronasal organ of garter snakes
Authors: Wang Ruu Tong , Halpern Mimi 
Published: February 2005

AbstractThe vomeronasal epithelium of adult garter snakes (Thamnophis sirtalis and T. radix) was studied by light and electron microscopy. The sensory epithelium is extraordinarily thick, consisting of a supporting cell layer, a bipolar cell layer, and an undifferentiated cell layer. The supporting cell layer is situated along the luminal surface and includes supporting cells and the peripheral processes (dendrites) of bipolar neurons. The luminal surfaces of both supporting cells and bipolar neurons are covered with microvilli. Specializations of membrane junctions are always observed between adjacent cells in the subluminal region. Below the supporting cell layer, the epithelium is characterized by a columnar organization. Each column contains a population of bipolar neurons and undifferentiated cells. These cells are isolated from the underlying vascular and pigmented connective tissue by the presence of a thin sheath of satellite cells and a basal lamina. Heterogeneity of cell morphology occurs within each cell column. Generative and undifferentiated cells occupy the basal regions and mature neurons occupy the apical regions. Transitional changes in cell morphology occur within the depth of each cell column. These observations suggest that the vomeronasal cell column is the structural unit of the organ and may represent the dynamic unit for cell replacement as well. A sequential process of cell proliferation, neuronal differentiation, and maturation appears to occur in the epithelium despite the adult state of the animal.
The distribution of monoamine oxidase and biogenic monoamines in the central nervous system of spiders (Arachnida: Araneida)
Authors: Meyer Wilfried , Jehnen Rosemarie 
Published: February 2005

AbstractThe distribution and activity patterns of monoamine oxidase and monoaminergic (formaldehyde‐induced) fluorescence in the central nervous system of web‐building and hunting spiders have been studied using histochemical methods. Enzyme activity occurred in the neuronal perikarya and in varying intensity in the structures of the neuropile mass, but only when dopamine, adrenaline, and noradrenaline were used as substrates. The optic centres of the spider brain normally exhibited relatively strong enzyme reactions when compared with the staining intensity of the rest of the nervous system.The neuronal cell bodies contained numerous granules of yellow‐green fluorescence. Monoaminergic fluorescence of the neuropile was generally a weak green. The optic mases of the hunting spiders, the anterior bridge, several commissures of the ventral cord, and the neural lamellae showed a slightly higher fluorescence intensity and single fluorescing granules.The results obtained indicate the presence of catecholamines in the spider nervous system.
Identification of the Y‐organ in the larval stages of the crab, Cancer anthonyi Rathbun
Authors: McConaugha John R. 
Published: February 2005

AbstractThe Y‐organ has been histologically identified in all six larval stages of the crab, Cancer anthonyi. The paired glands are located anterior to the branchial chamber and ventral to the base of the antennules. In the first zoeal stage the gland consists of a cord of 6 to 10 epidermal cells with dark staining nuclei, sparse cytoplasm, and indistinct cell boundaries. As development progresses the glands become more complex through extensive folding and intertwining of the cellular cords. The glands in all larval stages show cyclical activity which corresponds to the molt cycle. Immediately following a molt the gland is dense and compact with little cytoplasm. At approximately day four in the molt cycle, the glands become greatly hyperthropied due to an increase in the number and size of the cytoplasmic vacuoles. These histological changes suggests a cyclical production and presumably the release of some product most likely ecdysone.
An electron microscopic study of hemoglobin synthesis in the marine annelid, Amphitrite ornata (Polychaeta: Terebellidae)
Authors: Friedman Marc M. , Weiss Leon 
Published: February 2005

AbstractThe heart‐body of the marine worm Amphitrite, located within the supraesophageal dorsal vessel, is in the form of a cylinder the thin wall of which is deeply corrugated by luminal projections and folds along its entire length. It is anchored in places to the luminal surface of the dorsal vessel by an extracellular matrix containing collagen fibers. The luminal surfaces of both the heart‐body and the dorsal vessel are covered by a basement membrane‐like vascular lamina which in turn supports a discontinuous pseudoendothelium of littoral hemocytes.The cells of the heart‐body constitute a pseudostratified, high columnar epithelium. They possess extensive rough endoplasmic reticulum (RER), a well developed Golgi zone, ferritin particles and granules, and several types of membrane‐bound inclusions. Hemoglobin molecules identical to those in the circulation lie within cytoplasmic, membrane‐bound vesicles. Analysis of our electron micrographs suggests the following sequence of hemoglobin production and secretion: Large quantities of a moderately dense flocculent material, probably globin, are synthesized in RER and move to the Golgi zone within partly rough‐ and partly smooth‐surfaced transitional cisternae; small transport vesicles, formed from Golgi cisternae that have fused with transitional cisternae, convey the flocculent material from the convex to the concave face of the Golgi complex; a similar flocculent material and an amorphous, highly dense material are processed in the Golgi complex and are transferred to condensing vacuoles in which clearly identifiable hemoglobin molecules are first observed. Mature secretory vesicles containing only hemoglobin migrate to the cell periphery and discharge their contents by exocytosis. Hemoglobin molecules then cross the vascular lamina to reach the circulation.
Time‐lapse cinemicrographic studies of cell motility during morphogenesis of the embryonic yolk sac of Fundulus heteroclitus (Pisces: Teleosti)
Authors: Armstrong Peter B. 
Published: February 2005

AbstractThe active motility of the cells of the yolk sac of the living Fundulus embryo was studied by time‐lapse cinemicrography with phase contrast optics. In the teleost, the yolk sac lies peripheral to the body of the embryo proper and consists of a fluid‐filled space bounded above by a superficial epithelium, the enveloping layer (EVL), and below by the yolk syncytial layer (YSL). The cell types treated in the present study are the enveloping layer epithelial cell, the stellate cell which lies in a layer flattened on the inner surface of the EVL, the epithelioid deep cell, the yolk sac amoebocyte, the yolk sac endothelial cell and the yolk sac melanoblast. The most actively motile cells examined in the present study are the yolk sac amebocyte and the melanoblast, which emigrates from the embryo proper at stages 19–21. The amoebocytes are compact rounded cells that move very rapidly by the extension of lamellipods with scalloped margins. The amoebocytes wander over the yolk sac in an apparently undirected fashion and invade the embryo proper when they happen to encounter it, moving between cells of the lateral mesoderm. The melanoblasts migrate by the gradual extension of elongated branching processes. Cells are sometimes monopodial, with movement being parallel to the long axis of the cell. Alternatively, movement may be perpendicular to the predominant long axis, with processes being extended alternatively from opposite ends of the cell obliquely forward, so the path described is a zig‐zag to either side of the overall direction of movement. Although the melanoblasts show irregularity in their movement, the predominant direction of initial movement is away from the embryo proper. The major yolk sac blood vessels form in situ by the collective activities of presumptive endothelial cells that enclose volumes of the yolk sac space with sheet‐like processes from the cell body and from the extensions that connect cells into networks.
A comparative morphological and enzyme histochemical study on blood cells of the freshwater snails Lymnaea stagnalis, Biomphalaria glabrata, and Bulinus truncatus
Authors: Sminia Taede , Barendsen Lucie 
Published: February 2005

AbstractThe morphology and ultrastructure of the blood cells of the freshwater snails Lymnaea stagnalis, Biomphalaria glabrata, and Bulinus truncatus were studied. By performing in vitro experiments and enzyme histochemical studies, special attention was paid to the role of the blood cells in phagocytosis of foreign particles.No fundamental differences were found in the ultrastructure, lysosomal enzyme contents, and phagocytic capacities of the blood cells of these species. It is concluded that only one type of blood cell, the amoebocyte, exists in the freshwater snails. Amoebocytes constitute a morphologically and functionally heterogeneous population of cells, ranging from round (electron‐dense) cells with the morphological characteristics of young cells to highly phagocytic spreading cells with a prominent lysosomal system. In addition to acid phosphatase, nonspecific esterase and peroxidase were found within the lysosomes.The presence of enzyme activity in the RER and the Golgi bodies indicates that amoebocytes are able to synthesize lysosomal enzymes continuously.
Structure of the dermal scales in gymnophiona (Amphibia)
Authors: Zylberberg L. , Castanet J. , De Ricqles A. 
Published: February 2005

AbstractHistology and cytology of dermal scales of the gymnophionans Ichthyophis kohtaoensis and Hypogeophis rostratus reveal their structure and the nature of their mineralization.Dermal scales are small flat disks set in pockets in the transverse ridges of the skin. Each pocket contains several scales of various sizes. A ring of “hypomineralization” of varying diameter may occur on scales of a particular dermal pocket but bears no relation to the diameter of these scales.Three different layers form the scales and are seen on sections perpendicular to the surface. The cells of the basal layer lie deepest. Each of the two or three more superficial fibrous layers is composed of bundles of fibres that are oriented in parallel. The orientation varies among layers. The striation of the fiber scales has a periodicity comparable to that of the surrounding dermal fibers. Squamulae form a discontinuous layer on the scale surface and are the only mineralized part of the scale. The minerals are deposited both on the collagen fibers passing from the fibrous layers into the squamulae, and in the interfibrillar spaces. Spherical concretions, either isolated or coalescent, reaching up to 1 μm, are found on the surface of the squamulae.The dermal scales of Gymnophiona present some analogies with those of evolved bony fishes. Their characteristics could make them an original model for the study of mineralization.
Comparative studies on the statoblasts of higher phylactolaemate bryozoans
Authors: Mukai Hideo , Oda Shuzitu 
Published: February 2005

AbstractStatoblasts of five higher phylactolaemates were compared morphologically. As a result, they were divided into two groups: Group I comprising Lophopus crystallinus, Lophopodella carteri, and Pectinatella gelatinosa, and Group II comprising Pectinatella magnifica and Cristatella mucedo. These two groups are thought to represent independent evolutionary series. In Group I and in P. magnifica, the statoblasts are curved to varying degrees after the manner of a saddle. When the dorsal and ventral valves are flattened, therefore, the contour is different between the two. In Group I, the outermost layer of a mature statoblast is hard‐gelatinous and basophilic; it remains intact after the statoblast is set free. The statoblast does not float until it is dry, and the float is similar in size on both valves. In Group II, a mature statoblast is covered by a softgelatinous basophilic layer, which decays after the statoblast is released. The statoblast floats without drying, and the float is better developed on the dorsal valve than on the ventral. Moreover, in the members of Group II, large yolk granules are first formed, followed by much smaller yolk granules. When their statoblasts are treated with KOH, the shell is separated completely into two valves. These characters are common to many lower phylactolaemates. By contrast, in L. carteri and P. gelatinosa, the yolk granules are uniformly small and the capsule proper resists KOH treatment. On these points, L. crystallinus is somewhat different from these two species, suggesting its primitive nature.
Innervation of the parathyroid in the european starling (Sturnus vulgaris)
Authors: Wideman Robert F. 
Published: February 2005

AbstractAnatomical studies were conducted to characterize the source, type, and distribution of parathyroid gland innervation in European starlings. Denervation experiments demonstrated that the parathyroid glands and adjacent carotid bodies are innervated by nerve fibers originating in the nodose ganglion of the vagus nerve. In the parathyroid parenchyma, these fibers terminate adjacent to chief cells or near vascular smooth muscle. Vagal fibers also form synapses with catecholamine‐containing glomus cells of the carotid body. Blood that first perfuses the carotid body subsequently perfuses the parathyroid parenchyma. These observations suggest that vagal innervation may influence parathyroid function in starlings either through direct chief cell innervation or through alteration of vascular perfusion. A neurohemal relationship also may exist between the carotid body and parathyroids.
The digging behavior and skin differentiations in Heterocephalus glaber
Authors: Tucker Richard 
Published: February 2005

AbstractThe topography and histology of the skin of the naked mole (Heterocephalus glaber) have been correlated with its behavior. The integument is exceptionally loose, thereby reducing integumentary stresses when the animal is digging and moving in narrow tunnels. It also allows the position of the nasolabial sensory patch to change. This patch is exposed to mechanical stimuli when Heterocephalus moves along the tunnel, but becomes partially shielded by a transient buccal evagination, the formation and function of which are here described. Most of the differentiated patches of the skin lie in the cranial and anogenital regions. The eyes are microphthalmic and nearly completely closed by the nonmobile eyelids; there is no pinna, hair‐coat or sweat glands.The epidermis is of variable thickness; in some places it has only one layer of cells. The detached epidermal cells penetrate the dermis irregularly.The epidermis of Heterocephalus is specialized by modifications of its germinative stratum, equivalent to an epidermosis, the syndrome of which consists of reduction of all types of epidermal buddings—pilogenetic and adenogenetic—as well as those which have a mechanical significance.
Ultrastructure of the antennal sensilla of the cockroach‐egg parasitoid, Tetrastichus hagenowii (Hymenoptera: Eulophidae)
Authors: Barlin Margaret R. , Vinson S. Bradleigh , Piper Gary L. 
Published: February 2005

AbstractEggs of a number of cockroach species are parasitized by Tetrastichus hagenowii. The ultrastructure of the sensilla on the antennae of females and males was examined by scanning and transmission electron microscopy. The females have two types of multiporous plate sensilla while the males have only one. Type 1 is found in females and males and has a relatively thin cuticular wall and many pores, while type 2 is found only in females and has a relatively thick cuticular wall and few pores. Both sexes have nonporous, thick‐walled, socketed hairs; multiporous, nonsocketed hairs; multiporous, thick‐walled pegs; and terminal hairs. In addition, males have multiporous, nonsocketed, long hairs. The sensilla are similar, in many respects, to the sensilla of other chalcid parasitoids. The antennal sensilla of female T. hagenowii are probably involved in ovipositional behavior. The multiporous, long hairs of the male possibly receive stimuli during mating behavior A chemoreceptive function is proposed for the multiporous plate sensilla.