bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphogenesis and histochemistry of the developing mouse kidney
Authors: Redempta Vetter Sister M. , Gibley Charles W. 
Published: February 2005

AbstractA morphological and histochemical investigation was conducted on the pronephros and mesonephros of the mouse embryo from 8.5 through 16.5 days. The pronephros appeared between days 8.5 and 9.5 as a thickening of the somatic layer of the intermediate cell mass. It consisted of three small clusters of cells on either side of the midline dorsally between the somite and the coelom, at the level of somites 8 and 9. The mesonephros arose during day 9 and persisted until day 16. In the male the anterior three tubules were incorporated into the testis at 15.5–16.5 days. The mesonephros consisted of approximately 11 tubules located between somites 10–17. The tubules possessed lumina and connected with the Wolffian duct. Indications of internal and external glomeruli were noted on day 11. The Wolffian duct reached the cloaca at ten days.Strong alkaline phosphatase activity was noted in the differentiating tubules. Cytoplasmic and luminal enzyme activity was observed between 9.3 and 12.5 days indicating possible function at this time. Acid phosphatase was demonstrable in the tubules and duct only on day 11. Ribonucleic acid was observed in the nuclei and cytoplasm of the mesodermal cells as they differentiated into tubules and duct. A decrease in RNA was noted after differentiation was complete. Periodic acid‐Schiff material (diastase‐stable) was localized in the basement membrane of the tubule and duct cells. A faint positive reaction was also found at the luminal border of the tubules. The strongest reaction was noted in the luminal border at 11.5–12.5 days. Those tubules being incorporated into the genital system in the male were also PAS positive. Morphological and histochemical evidence suggested that the mouse mesonephros, though quasi vestigial, may function for a short time.
Choroid plexus and paraphysis in lower vertebrates
Authors: Shuangshoti Samruay , Netsky Martin G. 
Published: February 2005

AbstractCytoarchitecture of the choroid plexus of the third ventricle and the paraphysis was investigated in some lower vertebrates to compare the histologic characteristics of these organs. Both epithelia are similar in appearance in the same class. Minor microscopic variations exist in the different classes of vertebrates, but do not provide a fundamental distinction between the two organs. The epithelia, moreover, have similar staining properties, contain mucicarmine‐ and PAS‐reactive materials, and are derived from a common neuroepithelium. Tubules are identified in the choroid plexus and in the paraphysis; all are similarly formed by simple folding of epithelium on the surface into the stroma. The paraphyses in all vertebrates studied contain villi similar to those seen in the choroid plexus. Cilia are identified in both choroidal and paraphyseal epithelia, and are not an indication of degree of epithelial differentiation. Many types of epithelium are noted in both organs during histologic differentiation as well as in the mature stage. Functionally, the choroid plexus is active in both secretion and absorption. Accumulation of particulate material within the epithelial cytoplasm may indicate phagocytic as well as absorptive activity of cells. Based on a common neuroepithelial origin and similar histochemical properties, we conclude that the paraphysis is a modified choroid plexus. The velum transversum is an arbitrary boundary between diencephalon and telencephalon, and is itself formed of choroid plexus. The medial telencephalic ventricle is the rostral portion of the third ventricle. All neuroepithelial infoldings at the rostral end of the diencephalic roof including the velum transversum are intraventricular choroid plexuses; the neuroepithelial outpouchings in this region are the extraventricular choroid plexuses (paraphysis) of the diencephalon.
The structure and development of the digital lamellae of lizards
Authors: Ernst Valerie , Ruibal Rodolfo 
Published: February 2005

AbstractThe epidermal setae and the spinules of the digital lamellae of anoline and gekkonid lizards are shed periodically along with the rest of the outer layer of the skin. These structures are developed within the lamellae prior to ecdysis. The setae are larger and more complicated than the spinules and begin their development first. The setae of Anolis start as aggregations of tonofibrils beneath the plasma membrane of the presumptive Oberhautchen cells. These cells are arranged in rows parallel to the surface, several cell layers beneath the alpha layer of the skin. The developing setae protrude into the clear layer cells as finger‐like projections, with the tonofibrils longitudinally oriented in the direction of growth. About 100 setae are formed by each Oberhautchen cells in Anolis. In late development, the clear layer cells lose their cellular contents and when shed along with all distal cells, retain a template of the new setae or spinules. The spinules and setae are formed before the fibrous and alpha layers of the new skin. The fibrous layer, which occurs only on the ventral (outer) layer of the lamellae, and the Oberhautchen with its setae and spinules, is considered the beta layer. The alpha layer, which occurs adjacent to the fibrous layer on the ventral surface and adjacent to the Oberhautchen on the dorsal (inner) surface, is morphologically identical to that of mammalian α keratin. The shed lizard skin consists of the alpha and beta layers as well as the degenerating cells of the outer epidermal generation, and the clear layer. The clear layer that is shed shows the template of the new setae and spinules developed in the new skin layer. The separation of the new from the old skin occurs along the intercellular space between the clear layer cells and the new Oberhautchen. The alpha layer of the skin is not fully keratinized at shedding. The setae of the digital lamellae of lizards represent unique epidermal structures — intracellular keratinized microstructures.
Fine structure and origin of the tunic of Perophora viridis
Authors: Deck J. David , Hay Elizabeth D. , Revel Jean‐Paul 
Published: February 2005

AbstractThe fine structure of the tunic of a typical ascidian was investigated because of the cellulose‐like polysaccharide known to occur in its substance. The glycoprotein mantle does contain filaments very much like plant cellulose in morphology. Tunicin filaments are 35–50 Å in diameter, often beaded, and of indeterminate length. Histochemical evidence that they are composed of cellulose is given here and past chemical and physical studies on the unusual ascidian polysaccharide are reviewed. Moreover, we present here for the first time direct autoradiographic evidence that epidermal cells are involved in the synthesis and secretion of tunicin. Tritiated glucose is immediately incorporated into the Golgi zone of epidermal cells and labeled product appears in the tunic at later intervals. The fine structure of the epidermal cell is described in detail. Unlike the rather moribund appearing vanadocyte that wanders through the tunic, the epidermal cell has well‐developed cytoplasmic organelles and a large vesicular nucleus. The granular endoplasmic reticulum is abundant and the Golgi complex is highly developed. It seems likely that the lamellae and vesicles of the Golgi complex are involved in the production of the tunic sugar and that tunic proteins of as yet unknown nature are produced by the ergastoplasm. Further investigation of the ascidian mantle should be of interest because of the possibility that cellulose is a more general component of glycoprotein surface coats in animals than has heretofore been recognized.
Fine structure of the formation and fate of the residual bodies of mouse spermatozoa with evidence for the participation of lysosomes
Authors: Dietert Scott E. 
Published: February 2005

AbstractRoutine electron microscopy in combination with subcellular localization of acid phosphatase has been employed to study the formation and fate of residual cytoplasmic bodies extruded into the tubular lumen shortly before spermiation. Prior to extrusion the spermatid cytoplasm contains lipid droplets, mitochondria, ribosomes, endoplasmic reticulum, the caudally migrated Golgi apparatus, and numerous multivesicular and multigranular bodies. These membrane‐limited bodies and the Golgi zone stain heavily for acid phosphatase. Following extrusion the residual bodies undergo a series of alterations: (1) disruption of multigranular bodies with release of free granules; (2) sequestration of granules, ribosomes, and reticulum inside double‐membrane‐limited vacuoles derived from Golgi lamellae; (3) appearance of numerous, single‐membrane‐bound, cytoplasmic vacuoles; (4) fragmentation; (5) peripheral migration toward the tubular wall; and (6) phagocytosis of these migrating fragments by the Sertoli cells. The demonstration of acid phosphatase activity within free granules, the sequestering Golgi lamellae, and both classes of vacuoles suggests that initial residual body degradation occurs through lysosomal cytoplasmic autophagy.
Histochemical observations on mucin secretion by subsurface epithelial structures in the canine ovary
Authors: O'shea J. D. 
Published: February 2005

AbstractHistochemical methods for mucins were applied to the ovaries of 23 dogs.Solid and hollow groups and cords of epithelial cells (subsurface epithelial structures, SES) in the outer part of the cortex regularly showed evidence of mucin secretion. Intracytoplasmic, sialic acid‐containing, acid mucin secretion droplets were seen in solid and hollow SES, and secretion was present in both closed lumina and those opening onto the surface.Intracytoplasmic droplets in the cells of SES were distinctive, and similar droplets were not found in the cells of any other ovarian epithelial component. The secretion of SES was not shown to possess distinctive histochemical features.Mucin production was also observed in follicles, corpora lutea and rete tubules.The significance of ingrowth from the ovarian surface epithelium in adult life, and of secretory activity by the cells of SES, are discussed.
Ultrastructure of the crocodile kidney (Crocodylus acutus) with special reference to electrolyte and fluid transport
Authors: Davis Lowell E. , Schmidt‐Nielsen Bodil 
Published: February 2005

AbstractThe study of the ultrastructure of the kidney tubules of the crocodile was made to compare the cellular structure with the capacity for electrolyte resorption and the ability to create an osmotic gradient across the tubular wall. The crocodile tubular cells were found to differ from the mammalian tubular cells in that they do not have basal infoldings, but instead have open lateral spaces between the cells, similar in many aspects to those found in the mammalian gallbladder. The physiological role of these lateral spaces in solute and fluid transfer is discussed.
Embryology of the thoracic and abdominal ganglia of the large milkweed bug, Oncopeltus fasciatus (Dallas), (Hemiptera, Lygaeidae)
Authors: Springer Charles Anthony 
Published: February 2005

AbstractIn this study, the condensation of the three thoracic and 11 abdominal segmental ganglia to form a prothoracic and central nerve mass during embryogenesis is described. During katatrepsis, many changes occur in the organization of these ganglia; this study suggests that some of these changes are caused by mechanical forces acting on the ventral nerve cord at this time. The ventral nerve cord begins its anterior migration and coalescence ten hours after katatrepsis and is completed 63 hours later. The central ganglion is made up of the meso‐ and metathoracic ganglia and seven abdominal ganglia. Intrasegmental median cord nuclei are shown to form glial elements in the median sagittal plane of the neuropile and in the longitudinal connectives. Intersegmental median cord neuroblasts migrate into the posterior gangliomeres but, apparently, degenerate soon after katatrepsis. Lateral cord cells bordering on the neuropile form a glial investment that surrounds this fiber tract region. Peripheral lateral cord cells are shown to form the cells of the outer ganglionic sheath, the perineurium.
Histochemical studies on cell death and histolysis during regeneration I. Distribution of acid phosphomonoesterase activity in the normal, the regenerating and the resorbing forelimb of the larval spotted salamander, Amblystoma maculatum
Authors: Weiss Charles , Rosenbaum Robert M. 
Published: February 2005

AbstractHistochemical methods, especially azo dye methods for detecting acid phosphomonoesterase activity were applied to normal, regenerating and denervated, amputated limbs from larval Amblystoma maculatum. Efforts were made to control inactivation of enzymic activity and diffusion of both enzyme and reaction product. “Base‐line” values for enzymic activity were determined for normal limbs. Activity appeared most intense in macrophages, less intense in epidermis and cartilage matrix. Some activity was detected in Schwann cells, peri‐ and endoneurium and muscle fibers form normal limbs. Enzymic activity in regenerating limbs was strongest within macrophages which appeared in increased numbers especially in early stages. Wound tissue showed little increased activity. As the blastema formed, increased enzymic activity was detected in epidermis and within increased numbers of macrophages. Chondrocytes showed increased activity especially during cartilage matrix deposition. Amputated, denervated limbs showed large numbers of active macrophages beneath and within epidermis and along muscle. As regression commenced, areas of cartilage matrix breakdown showed increased enzymic activity but, in general, greatest activity was in macrophages. The various possible roles of acid phosphomonoesterase activity in the specific biological situations dealt with are considered in light of such observations.
The development of neuromasts in Cirrhina mrigala Ham. Buch. (Cyprinidae) and Ophicephalus (Channa) punctatus Bloch (Channidae)
Authors: Srivastava M. D. L. , Srivastava C. B. L. 
Published: February 2005

AbstractThe development of neuromasts was studied in two species of teleosts, Cirrhina mrigala Ham. Buch. and Ophicephalus punctatus Bloch, and the findings are presented and discussed. It has been discovered, in the course of this investigation, that a neuromast arises by a process of invagination — a fact hitherto not reported. The occurrence of the dorsal lateral line and the accessory lateral line of the trunk, in addition to the main lateral line, has also been reported for the first time for teleosts, although known for other bony fishes.
The fine structure of developing bristles in wild type and mutant Drosophila melanogaster
Authors: Overton Jane 
Published: February 2005

AbstractIn an attempt to understand the factors involved in morphogenesis of a complex cell like a scale or bristle, the fine structure of the normal development of bristle cells in Drosophila melanogaster (Oregon R) has been studied and compared with that of the mutants sn3 and Sb. In the development of the normal bristle rounded bundles of longitudinally oriented fibrils lie just beneath the cell surface at regularly spaced intervals. Fiber bundles constitute about 20% of the cross sectional area. The cytoplasmic surface between these bundles is active in enveloping the nerve fiber associated with the bristle and in sending out cytoplasmic processes associated with which the longitudinally oriented bristle ridges form. Singed bristles are bent and twisted and the fiber bundles are present as flattened bands constituting only about 5% of the cross‐sectional area. In Sb mutants the total cross‐sectional area of fiber bundle material is the same as that in Oregon R, but fiber bundles are smaller and more numerous, being distributed over the larger surface of this thicker and shorter bristle. They constitute only 7% of the cross‐sectional area of the bristle. In Sn3Sb mutants characteristics of each gene are exaggerated and an extremely short, wide, and irregular bristle is formed.
The failure of exoskeletons and endoskeletons
Authors: Currey J. D. 
Published: February 2005

AbstractA theoretical analysis is made of the mechanical advantages of exoskeletons and endoskeletons. More complicated and realistic loading systems are considered than have been by previous authors. For all cases involving static loading, an exoskeleton would seem to be advantageous, but sometimes the advantage is quite small. If impact is considered, the advantage of exoskeletons becomes very much reduced, even on theoretical calculations; and it is likely that in life the advantage may be converted to a disadvantage, particularly in large active animals such as vertebrates.
Development of the corpuscles of stannius in the anabantid teleost, Colisa lalia
Authors: Krishnamurthy V. G. 
Published: February 2005

AbstractThe development of Stannius corpuscles in the teleost Colisa lalia is described. Certain cells of the mesonephric tubules differentiate and proliferate to form buds which evaginate and finally become separated from the structure of origin. The separated cellular masses undergo further histologic differentiation to attain the adult structures.The corpuscles in C. laha, in contrast to some other teleosts, develop only from mesonephric tubules. A possible explanation for the different types of distribution of Stannius corpuscles in teleosts is suggested, and the possible homology of these structures with part of the adrenal cortex or higher vertebrates is discussed.
Epidermal morphology and sloughing frequency in normal and prolactin treated Anolis carolinensis (Iguanidae, lacertilia)
Authors: Maderson P. F. A. , Licht P. 
Published: February 2005

AbstractThe morphology of the epidermal generations throughout the sloughing cycle of Anolis carolinensis is essentially the same as that described for other squamates, whether studied in control or hormone‐injected animals. Readily identifiable granules in the clear layer of this and other lizard species emphasize the eventual hardening of this layer prior to its separation from the subjacent Oberhautchen, which brings about sloughing. Eosinophils are described for the first time in the lacunar tissue of lizard, but their functional role remains problematical. Daily 25 μg injections of prolactin (alone or in combination with gonadotropins) raise the frequency of sloughing by shortening the resting phase as compared with controls and animals receiving 1.0 I.U./day injections of gonadotropins. The duration of the proliferation‐renewal phase and the pattern of histological changes occurring therein is unchanged by experimental treatments. The results show that neither endogenous nor exogenous gonadotropins affect the sloughing frequency, but exogenous prolactin produces a similar effect to that described for thyroxine. Although the mechanisms of action are unknown, the results provide another example of the cutaneous action of prolactin in vertebrates.
Studies on the rabbit appendix. I. Lymphocyte‐epithelial relations and the transport of bacteria from lumen to lymphoid nodule
Authors: Shimizu Yoshifusa , Andrew Warren 
Published: February 2005

AbstractA correlated light and electron microscope study was made of lymphocyte‐epithelial relations in the appendix of normal rabbits, ranging in age from one week to ten months. The lymphocyte migration into the epithelium was very slight at one week. The lymphocytes were increased considerably in number from two weeks to three months, grouping into unique nests in the epithelium. The basement membrane began to be penetrated by migrating cells at one week and bacame discontinuous in older animals. At one and two weeks, the epithelial cells contained glycogen, which disappeared at three weeks. Degenerating cells as well as bacilli were found in the epithelial cells and in the macrophages of the nodules. The varied appearance of bacilli in the macrophages indicates that they were being digested. The lymphocytes in the epithelium were larger, having less crowded cytoplasm as compared with those in the lymph nodules. Many lymphocytes were in deep folds of epithelial cells. There was evidence favoring an intracellular position for some lymphocytes in the epithelium.
Cyclic changes in the ovary of the brook stickleback Eucalia inconstans (kirtland)
Authors: Braekevelt C. R. , McMillan D. B. 
Published: February 2005

AbstractThe ovarian cycle of the brook or 5‐spined stickleback was studied histologically. Specimens were trapped between July, 1965 and August, 1966 in a shallow pond near London, Ontario.Spawning took place from mid‐April to mid‐July, when the water averaged 10°C. In early August, When the water averaged 20–22°C for prolonged periods, spawning ceased and the ovaries contained only oögonia, atretic mature oöcytes and empty follicles. Oögonia and immature oöcytes were found throughout the year but only in the spring did the mature stages begin to appear.Oöcytes for each year's spawning appear to arise mitotically from a residual stock of lightly basophilic oögonia. As the oöcytes mature, their basophilia increases and they acquire a vitelline membrane and follicular layer. The deeply basophilic cytoplasm of the early oöcyte becomes frothy, as oily droplets of primary yolk are laid down. Finally, it becomes filled with eosinophilic secondary yolk in the mature egg.Two types of atresia of developing eggs are common, especially during and after the spawning period. The first involves active phagocytosis of yolky material and hypertrophy of the follicular layer, leading to the formation of what could be called a “corpus luteum.” In the second type of atresia, neither phagocytosis nor hypertrophy was seen and nothing resembling a corpus luteum was formed.
The structure of developing muscle insertions in insects
Authors: Lai‐Fook Joan 
Published: February 2005

AbstractThe relationship between muscles and the components of the integument in muscle insertions have been studied with the electron microscope in two insects, Calpodes ethlius (Hesperiidae, Lepidoptera) and Rhodnius prolixus (Reduviidae, Hemiptera). The area of contact between the muscles and the epidermis is increased by interdigitating processes whose membranes are joined by intermediate junctions. The junctions occur at the level of a Z line so that actin filaments attach directly to them. Within the epidermis, microtubules extend from the junctions of the myoepidermal connection to the cuticle, where they attach to hemidesmosomes which line deep indentations of the membrane. The microtubules probably enable the tendinous epidermal cells to withstand the tensions exerted upon them by the muscles. The epidermis is anchored to the cuticle by tonofibrillae, homogeneous rods secreted in the deep indentations of the plasma membrane. Since the tonofibrillae of successive instars are continous, they penetrate and attach to the cuticulin, the outermost layer of the epicuticle.
Sense organs on the antennal flagellum of a praying mantis, Tenodera angustipennis, and of two related species (Mantodea)
Authors: Slifer Eleanor H. 
Published: February 2005

AbstractAbout 10,000 sense organs are present on one antenna of a female mantis, Tenodera angustipennis, and nearly 40,000 on that of a male. These are of four kinds: (1) thick‐walled pegs, (2) short thin‐walled pegs, (3) medium length thin‐walled pegs and (4) long thin‐walled pegs. All have the structural characteristics of chemoreceptors. The dendrites of the sensory neurons of the thick‐walled pegs are exposed to the air in an opening at its distal end and those of the thin‐walled pegs terminate at many pores in the surface. The significance of the larger number of sense organs possessed by the male is discussed. No important differences were found between the antenna of Tenodera angustipennis and those of T. aridifolia and T. australasiae.