bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structure of comblike teeth of the ayu sweetfish, Plecoglossus altivelis (Teleostei: Isospondyli): I. Denticles and tooth attachment
Authors: Uehara Kiyoko , Miyoshi Sakuichiro 
Published: February 2005

AbstractThe structure and tooth attachment of the comblike teeth and denticles of the ayu sweetfish, Plecoglossus altivelis, were examined by light and scanning electron microscopy. The denticle is composed of a spoonlike crown with a spine pointed anteriorly, a triangular plate in the cervical region, and a root that curves laterally and tapers off to a point. The root apex is fused with a long thin pedicle that turns abruptly anteriad toward the jaw bone. Planes of the spine, the spoonlike crown, the triangle plate and the root of the denticle are varied, and the denticle is twisted in the region of the triangle plane.The superficial layer of the dentine is homogeneously calcified and is considered to be enameloid, because some of the inner dentinal epithelial cells in the tooth germ are columnar and possess cellular processes at their apical ends. The dentine is fibrous and fine dentinal tubules are visible in dentine treated with sodium hydroxide and observed by scanning electron microscopy. The upper half of the root is surrounded by a dense layer of collagen fibers running parallel to the tooth axis, and the lower half is encompassed by interlaced collagen fibers. The lower part of the root is open on its lingual side. The pedicle is a long rod which is homogeneously calcified and enmeshed by interlaced collagen fibers, and it curves mediad as it nears the jaw bone. The pedicles are interposed between a layer of gelatinous connective tissue and the jaw bone and terminate on the periosteum. Comparative aspects of ayu tooth morphology are discussed. © 1993 Wiley‐Liss, Inc.
Effects of juvenile hormone analogues upon soldier differentiation in the termite Reticulitermes santonensis (Rhinotermitidae, Heterotermitinae)
Authors: Lelis A. T. , Everaerts C. 
Published: February 2005

AbstractUnder the influence of juvenile hormone analogues (JHAs), termite workers are induced to differentiate into soldiers. In Reticulitermes santonensis, such induced differentiation is often incomplete, resulting in intercaste production. The morphology of the structures most affected during differentiation was analyzed descriptively and biometrically in normal workers, presoldiers, and soldiers, and in experimental intercastes. We observed that intercastes form a morphological and biometrical continuum between workers and presoldiers (presoldier intercastes), and between presoldiers and soldiers (soldier intercastes). We also compared the biochemistry of the normal individuals and of the intercastes; in contrast to workers, the intercastes possess a frontal gland secretion which differs from those of the presoldiers and soldiers. Besides intercaste characterization, we consider the mode of action of JHAs in termite differentiation. © 1993 Wiley‐Liss, Inc.
Microtopography of Nippostrongylus brasiliensis (Nematoda: Heligmosomatidae): Free‐living larval stages
Authors: Nembo B. , Goudey‐Perriere F. , Gayral P. , Perriere C. , Brousse‐Gaury P. 
Published: February 2005

AbstractMicrotopographic features of the various growth stages of the three free‐living larval stages of the rat hookworm Nippostrongylus brasiliensis (Nematoda) were surveyed by scanning electron microscopy. These worms have a rounded anterior end and an elongated tail. Cuticular annulations were observed along the body, which also bore two ribbon‐like lateral alae. Two rings of six lip‐like lappets were observed around the triradiate oral opening in all larval stages. The cephalic space contained two lateral amphidial pits. The excretory pore in the third anterior part was observed in a ventral view of the larvae. No deirids were observed. The anus with a crescent‐shape opening was located posteriorly. Phasmidial apertures, only observed in the third‐stage larvae, opened on the lateral alae in the tail region. © 1993 Wiley‐Liss, Inc.
Ultrastructural study of the esophagus of seawater‐and freshwater‐acclimated Mugil cephalus (Perciformes, Mugilidae), euryhaline marine fish
Authors: Cataldi Eemilia , De Merich Diego , Pesce Maurizio , Cioni Carla 
Published: February 2005

AbstractThe esophagus of the common grey mullet Mugil cephalus shows a single mode of organization that is common to both seawater‐ and freshwater‐acclimated specimens. A short anterior segment is lined by a stratified epithelium with mucous cells; posteriorly, this is progressively replaced by single‐layered columnar epithelium. Ultrastructural features of the columnar epithelium are quite similar in the seawater‐ and freshwater‐acclimated specimens. Apical microvillous projections, lamellar structures, and dilated intercellular spaces are observed. The present study suggests that the mullet esophagus is involved in active ion transport and water permeability, both in seawater and in freshwater environments. © 1993 Wiley‐Liss, Inc.
Polymorphic crystalline structure of fish otoliths
Authors: Gauldie R. W. 
Published: February 2005

AbstractAlthough most otoliths of teleost fishes contain aragonite, a detailed survey of the otoliths of serveral species confirms that other crystalline forms of calcium carbonate occur. Otoliths of Hoplostethus atlanticus, Pagrus major, Macruronus novaezelandiae, Merluccius australis, Congiopodus coriaceus, Kathetostoma giganteum, Argentina elongata, Rhomobosolea tapirina, Neophrynichthys latus, Coelorinchus aspercephalus, Paranothothenia microlepidota, and Gonorhynchus gonorhynchus contained the aragonite, calcite, and vaterite morphs of calcium carbonate in varying proportions. Aragonitic otoliths of Allocyttus niger, Hoplostethus altlanticus, and Pagrus major contained sequences of calcite‐like crystals. The surface of the vateritic otolith of Acipenser brevirostrum is shown in detail. Three classes of information are stored in the crystalline structure of the otolith: shape conservation, coexisting crystal morphs, and consecutive changes in crystal morph. Analysis of this crystalline information supports the hypothesis of control of growth of the otolith by proteins from the sensory epithelium or macula. Protein variation involved may be genetic in origin, or non‐genetic arising from “stuttering” of the translation process. Proteins extracted from vateric and aragonitic morphs of the otolith of Macruronus novaezelandiae showed differences in infared absorption spectra that were consistent with two different amino acid sequences. © 1993 Wiley‐Liss, Inc.
Ultrastructure of the granulocytes of the South American lungfish, Lepidosiren paradoxa: Morphogenesis and comparison to other leucocytes
Authors: Bielek Edith , Strauss Bernhard 
Published: February 2005

AbstractUltrastructure and peroxidase cytochemistry of the granulocytes of the lungfish Lepidosiren paradoza were investigated. In peripheral blood and hemopoietic tissue (kidney and spleen) only three granulocytic types were found. After comparison with light microscopic images of Giemsa‐stained semithin sections the granulocytes were tentatively designated as eosinophilic I, eosinophilie II, and a basophilic type.The eosinophilc I cell was the most numerous granulocyte and was characterized by granules ranging in diameter from 0.2–1.8 μm. A developmental series was observed, leading from small, peroxidase (PO) positive granules to large ones with PO‐negative cores and only peripheral PO‐positive reactivity. The central electron‐dense cores of the large granules were often eroded. The eosinophlic II cell was less numerous than the eosinophilic I type and had smaller (diameter 0.4–0.9 μm) granules than the eosinophilic I type, some of them elongated and rod like. The basophilic cell was rare and contained large, homogenously dense granules measuring up to 1.2 μm in diameter. Immature stages of the granulocytic types showed vesicular rough endoplasmic reticulum. Nuclear identation and segmentation occurred early in development, in contrast to the relatively late onset of these processes in mamals. Monocytes and macrophages had an irregular or slightly indented nucleus and lacked the specific granules of the granulocytes.Phylogenetic relationships were discussed with special reference to the question of the evolution of only one or possibly of two separate heterophilic/neutrophilic cell lines in fishes. © 1993 Wiley‐Liss, Inc.
The vomeronasal duct has a protracted postnatal development in the mouse
Authors: Coppola David M. , Budde Jason , Millar Leah 
Published: February 2005

AbstractRecent evidence suggests that the accessory olfactory system (AOS) may mediate chemoreception before birth. Such a capability may allow the fetus to begin to sample chemical stimuli from the outside world, a possibility that has important developmental and evolutionary implications. Herein we describe the development in the mouse of the duct that connects the vomeronasal organ (VNO), containing the primary receptor neurons of the AOS, with the nasal cavity and thus with external stimuli. Twenty‐four mice, four at each of six different ages from the last day of gestation through 25 days of age, were fixed and embedded in glycol methacrylate. Serial sections were examined under the light microscope so that the VNO duct could be reconstructed in three dimensions. Results confirm an earlier study which demonstrated that the VNO duct is not patent before birth. The duct becomes patent sometime after the first day of life but remains in an immature condition throughout the normal prepubertal period. During this period the duct is characterized by an internal surface that is rapidly desquamating such that the lumen of the duct contains sloughed tissue. These results suggest that the VNO is unlikely to function in the prenatal period, since the route for external stimuli to reach its receptor surface is blocked. The protracted period of VNO duct development reported here is consistent with the great bulk of data on the AOS of mammals which firmly establishes its role in the detection of pheromones which coordinate reproduction. © 1993 Wiley‐Liss, Inc.
The aponeuroses of the lacertilian ankle
Authors: Russell Anthony P. 
Published: February 2005

AbstractDespite pioneering and detailed work by McMurrich (Am. J. Anat. 4:33–76, '05; Am. J. Anat. 6:407–437, '07), the structure of the “plantar aponeurosis” of the lacertilian pes has remained poorly understood. In recent years a better understanding has been gained of the form and function of the mesotarsal joint of the lacertilian ankle and its role in the mechanics of sprawling locomotion. These developments have necessitated a reevaluation of the structural relationship of the “plantar aponeurosis” because McMurrich's (Am. J. Anat. 4:33–76, '05; Am. J. Anat. 6:407–437, '07) studies indicated that the aponeurosis is complex and should not be considered as a single sheet of connective tissue. The current contribution presents a detailed analysis of the anatomical relationships of the stratified aponeurotic sheets that traverse the ankle joint and attempts to relate these components to previous analyses of the functioning of the anlkle during locomotion. © 1993 Wiley‐Liss, Inc.
Cytochemical characterization of the hemocytes ofLeucophaea maderae(Dictyoptera: Blaberoidea)
Authors: Fenoglio C. , Bernardini P. , Gervaso M. V. 
Published: February 2005

AbstractA correlated morphological and cytochemical approach to the hemocytes inLeucophaea maderaecharacterizes the granule contents of blood cells with May Grunwald‐Giemsa (MGG), periodic acid‐Schiff (PAS), Alcian blue (AB), and Sudan black B stainings, and after fluorochroming with acridine orange (AO). The cell nucleus and nuclear DNA is demonstrated with the Feulgen reaction. The activities of α‐naphtyl butyrate esterase (ANBE) and acid phosphatase (AcPase) have been investigated in hemocytes, by both light and electron microscopy. The study discloses five cells types: prohemocyts, plasmatocytes, granulocytes, spherulocytes, and cytocytes. Occasional Sudan black‐positive cells could represent an adipohemocyte category. The different patterns of cytochemical staining suggest a variety of functional roles for hemocytes. The most selective reaction pattern in terms of cytological differentiation among hemocytes occurred with the ANBE reaction. Ultrastructural analysis of intercellular granule contents, and the demonstration of cells with intermediate features, suggests that the hemolymph ofLeucophaea maderaecontains a developmental series from prohemocyte to plasmatocyte to granulocyte and then to spherulocyte. © 1993 Wiley‐Liss, Inc.
Increased vascularity of the lingual salt glands of the estuarine crocodile, Crocodylus porosus, kept in hyperosmotic salinity
Authors: Franklin Craig E. , Grigg Gordon C. 
Published: February 2005

AbstractMethyl methacrylate corrosion casts were made of the blood‐vascular system of the lingual salt glands of the estuarine crocodile, Crocodylus porosus, and examined with light and scanning electron microscopy. The 28–40 individual salt glands, each opening separately via a single pore onto the dorsal surface of the tongue, are supplied by a pair of lingual arteries. Each gland is richly vascularized and is composed of 14–20 lobular sub‐units, each having a dense network of capillaries. The blood flow in each gland is from the centre to its periphery, opposite to the direction of the flow of secretions in the ducts of the gland. The main collecting duct leading from the gland to the external pore was well vascularized. The blood supply to the glands of juvenile crocodiles raised in 20‰ salt water was more dense than in freshwater and, from cast masses, had a three‐fold greater vascular volume. This study provides the first evidence which shows that the salt glands of crocodiles are morphologically labile and can adapt to the environmental salinity. © 1993 Wiley‐Liss, Inc.
Morphology of the basilar papilla of the budgerigar, Melopsittacus undulatus
Authors: Manley Geoffrey A. , Schwabedissen Gabriele , Gleich Otto 
Published: February 2005

AbstractThe budgerigar is a representative of the parrot‐like birds that, like song birds, have developed complex communication signals. This species is interesting in a psychoacoustic sense, in that it shows unusually good frequency discriminative abilities above about 1 kHz. To begin to understand whether the peripheral hearing organ plays a role in such specializations, we have carried out a quantitative study of the fine anatomy of the basilar papilla and compared it to data from other avian species.The budgerigar basilar papilla is about 2.5 mm long in the living animal and contains about 5,400 hair cells. The hair cells of the papilla show regional specializations similar to those found in other birds and are described from scanning electron microscopic and light microscopic studies. Regiona changes in the basilar papilla, and in the basilar and tectorial membranes are described from light microscopic data. As noted for other avian species, the constellation of morphologic features found in the budgerigar is unique. In general, the hair cell patterns of the budgerigar papilla showed fewer specializations than found in, e.g., a songbird, the starling, but more than seen in a primitive land bird, e.g., the pigeon. There were no features that were obviously related to the unusal psychoacoustic performance of this species. © 1993 Wiley‐Liss, Inc.
Stages of oocyte development in the zebrafish, Brachydanio rerio
Authors: Selman Kelly , Wallace Robin A. , Sarka Andrew , Qi Xiaoping 
Published: February 2005

AbstractOocyte development has been divided into five stages in the zebrafish Brachydanio rerio, based on morphological criteria and on physiological and biochemical events. In stage I (primary growth stage), oocytes reside in nests with other oocytes (Stage IA) and then within a definitive follicle (Stage IB), where they greatly increase in size. In stage II (cortical alveolus stage), oocytes are distinguished by the appearance of variably sized cortical alveoli and the vitelline envelope becomes prominent. In stage III (vitellogenesis), yolk proteins appear in oocytes and yolk bodies with crystalline yolk accrue during this major growth stage. Ooctes develop the capacity to respond in vitro to the steroid 17α, 20β‐dihydroxy‐4‐pregnen‐3‐one (DHP) by undergoing oocyte maturation. In stage IV (oocyte maturation), oocytes increase slightly in size, become translucent, and their yolk becomes non‐crystalline as they undergo final meiotic maturation in vivo (and in response to DHP in vitro). In stage V (mature egg), eggs (approx. 0.75 mm) are ovulated into the ovarian lumen and are capable of fertilization. This staging series lays the foundation for future studies on the cellular processes occurring during oocyte development in zebrafish and should be useful for experimentation that requires an understanding of stage‐specific events. © 1993 Wiley‐Liss, Inc.
Ultrastructural study of the ovary of the sessile scyphozoan, Haliclystus octoradiatus (Cnidaria: Stauromedusae)
Authors: Eckelbarger Kevin J. , Larson Ronald J. 
Published: February 2005

AbstractAn ultrastructural study of the ovary of the sessible jellyfish, Haliclystus octoradiatus, indicates that it is fundamentally different from that of other scyphozoans and is the most structurally complex within the class. Oocytes develop within a series of spherical, sac‐like ovarian follicles consisting of an enlarged intercellular space between two layers of subumbrellar gastrodermis. Developing oocytes are largely restricted to a thin germinal epithelium at the periphery of each follicle and gradually migrate toward the lumen as they mature. Individual oocytes are surrounded by early germ cells and follicle‐like accessory cells of presumed somatic origin. Similar folliclelike cells have not been described in the Cnidaria previously. Vitellogenesis appears to involve the combined activity of the Golgi complex and associated rough endoplasmic reticulum. Ovarian morphology may be helpful in deciphering phylogeneitc relationships within the Cnidaria. © 1993 Wiley‐Liss, Inc.
Reproduction, placentation, and embryonic development of the Atlantic sharpnose shark, Rhizoprionodon terraenovae
Authors: Castro José I. , Wourms John P. 
Published: February 2005

AbstractThe Atlantic sharpnose shark Rhizoprionodon terraenovae (Richardson) is a small carcharhinid that is a common year‐round resident along the southeast coast of the United States. It is viviparous and its embryos develop an epithelio‐vitelline placenta. Females enter shallow water to give birth in late May and early June. Mating occurs shortly after parturition, and four to seven eggs are ovulated. Fertilized eggs attain the blastoderm stage in early June to early July. Separate compartments for each egg are formed in the uterus when the embryos reach 3–30 mm. Embryos depend on yolk for the first 8 weeks of development. When embryos reach 72 mm their yolk supply is nearly depleted and they shift to matrotrophic nutrition. When the embryos reach 40–55 mm, placental development begins with the vascularization of the yolk sac where it contacts the uterine wall. Implantation occurs at an age of 8–10 weeks by which time the embryos reach 70–85 mm. The expanding yolk sac engulfs the maternal placental villi, and its surface interdigitates with the villi to form the placenta. The rest of the lumenal surface of the uterus is covered by non‐placental villi that appear shortly after implantation. Histotrophe production by the non‐placental villi begins just after their formation. The placenta grows continuously during gestation. The egg envelope is present throughout gestation, separating maternal and fetal tissues. Embryos develop numerous appendiculae on the umbilical cord. Young sharks are born at 290–320 mm after a gestation period of 11 to 12 months. © 1993 Wiley‐Liss, Inc.
Structure and swimming behavior of the larva of Haliclona tubifera (Porifera: Demospongiae)
Authors: Woollacott Robert M. 
Published: February 2005

AbstractEarly developmental stages of Haliclona tubifera are retained by the parent and larvae are released on illumination of dark‐adapted colonies. Larvae are parenchymellae without provision for feeding on particulate matter and without identifiable sensory and neuronal elements. Larvae, however, are strongly photonegative on release and remain so throughout the duration of larval existence. The anterior and lateral epidermal fields are composed predominantly of elongate flagellate cells which form a pseudostratified columnar epithelium. Interspersed among elongate cells are globular flagellate cells which, based on ultrastructural criteria, are thought to be secretory in function. The posterior surface is not flagellated and is composed of a cuboidal epithelium. A 5–7 cells wide ring of epidermal cells with flagella 50 μm in length forms a prominent flagellar band separating the posterior from lateral fields. Measurements of swimming speeds in the horizontal plane indicate that H. tubifera larvae swim at speeds intermediate between Halichondria melanadocia, which have a posterior tuft of 25 μm flagella and Haliclona sp, with a posterior ring 75 μm flagella. Morphometric analysis of larval length, larval diameter, and flagellar band diameter shows significant correlations in all pair‐wise tests. Band diameter varies less than larval length or width suggesting that it is a conserved trait. A negative allometry exists between band diameter and larval length. As larval length increases elongate flagellar cells of the lateral and anterior surfaces become relatively more important for locomotion. A prominent cup‐like sheath of subepidermal cells separates the epidermis from the central region of the larval interior. These cells are not associated with collagen as are cells similar in appearance and location in several other haplosclerid larvae. Their function remains unknown. Spicules occur in the posterior region. As in the adult, these spicules are hastate oxeas, but they are significantly different in length, width, and length/width from those of the adult. Their function is unknown, but several obvious potential functions in both larval and postlarval life exist and await further study. Archeocytes are the dominant cell type of the central region. Bacteria are found inter‐ and intracellularly. Based on morphological data, they appear to be of a single type, pleomorphic rods without thick walls, but further study utilizing isolates in culture is needed to establish their diversity and identity. Intracellular bacteria are associated with a cell type provisionally designated a bacteriocyte. Three stages of bacteriocytes are described based on anatomical criteria, presence/absence of bacteria, and what appear to be stages in degradation of bacteria. The significance of this association and of the bacteriocyte cell type remain to be explored. © 1993 Wiley‐Liss, Inc.
Ultrastructure of the paraphysis in Bufo bufo larvae
Authors: Farnesi Rosalba M. , Tei Simonetta , Vagnetti Daniela , Santarella Bruna , Pollacci Paola 
Published: February 2005

AbstractA study of the ultrastructure and function of the paraphysis in Bufo bufo larvae was carried out. The structure is a tubular‐ramified gland made up of numerous tubules with monolayered epithelial walls surrounded by connective tissue and sinusoids. The epithelial cells secrete glycoprotein to contribute to production of the cephalorachidian fluid. The role of the paraphysis in the transport of fluids and electrolytes from the blood to the cephalorachidian fluid in regulation of ionic and osmotic homeostasis is discussed. © 1994 Wiley‐Liss, Inc.