bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rapid wax plate modeling
Authors: Sack W. O. 
Published: February 2005

AbstractAn accelerated method for the production of wax plate models from serial sections is described. Serial sections are projected on the back of 1 mm wax plates and the sharp image produced on the front of the plate is cut out directly with a knife. The construction of a simple projection apparatus which permits back‐lighted projection is described and illustrated. The apparatus is built of common‐size lumber and a small sheet of Plexiglas. It consists of a screen for the image and a wooden track on which a light source and microscope can be moved back and forth for different magnifications. Commercially available wax plates can be used. A method and the equipment needed to produce larger plates are described.The cut‐out images when piled up to form the model are welded together and strengthened by inserting heated straight pins. The exterior of the model is smoothed with an electrically heated glass instrument which provides constant heat of desired temperatures. The construction of the glass instrument is illustrated.
Morphological variability of keratohyalin
Authors: Farbman Albert I. 
Published: February 2005

AbstractWith the aid of the electron microscope, it has been possible to demonstrate that the configuration of keratohyalin in rat tongue epithelium is highly variable. The configurations described by others are seen, i.e., the globular or irregular granules made up of homogeneous electron‐opaque material. In addition to these, there are two other types of granules. One type is constituted heterogeneously of material similar in density to that usually described and another slightly less dense material. In the other type, keratohyalin is arranged as a dense rim around an electron‐translucent, amorphous center. In addition to the cytoplasmic keratohyalin granules, intranuclear dense granules were demonstrated. The morphology of these intranuclear granules is similar in some ways to cytoplasmic keratohyalin.
Response of murine cutaneous nerves to skin painting with methylcholanthrene
Authors: Fitzgerald M. J. T. , Lavelle S. M. 
Published: February 2005

AbstractA saturated solution of 20‐methylcholanthrene in benzene was applied to the ear and trunk of 59 BALB mice. The effects upon cutaneous innervation were compared with that of 50% turpentine in acetone (13 mice) and of skin abrasion with sandpaper (11 mice). Silver impregnation techniques showed that the carcinogentreated epidermis was invaded by nerve fibers whose number was related to the degree of epidermal hyperplasia, but not to the period of treatment or to the animals' age at the time of first painting. Hair follicles showed changes in the size, number and length of nerve endings. Growth of cutaneous nerves was already evident on the fourth day of exposure to methylcholanthrene. Turpentine elicited only a slight neural reaction after 60 days; and the sandpaper treatment was without effect.
Fertilization and early development after radiocobalt irradiation of rabbit oocytes and sperm in the female tract
Authors: Chang M. C. , Hunt Dorothy M. , Turbyfill C. L. 
Published: February 2005

AbstractOne hundred and seven female rabbits were divided into three groups and irradiated with 400 r from a radiocobalt source. The first group (71 animals) was irradiated before or 4–12 hours after mating and an ovulating injection of H.C.G. The second group (27 animals) were irradiated at about the same time after injection but inseminated after irradiation. The third group (9 animals) were inseminated with spermatozoa which had been irradiated in other females.The ova were recovered at various times for the determination of fertilization, cleavage, and blastocyst formation. Groups of animals were autopsied 14 or 29 days later for the determination of fetal development. The fertilization rate was not disturbed whether sperm, oocytes, or both were irradiated. The disturbance of nuclear material, the aberration of chromosomes, the retardation of cleavage, the fragmentation of cytoplasm, and the failure of blastocyst formation and embryonic development were observed especially whenever oocytes were irradiated. Irradiation of oocytes before mating and injection appeared to be less harmful but no differential effects were observed when irradiation was at 4, 6, 8, 10 or 12 hours after ovulating injection or when oocytes alone or both the oocytes and sperm were irradiated, probably due to the dosage being too high. Irradiation of sperm in the female tract was less harmful, normal blastocysts and apparently normal fetuses were obtained when nonirradiated ova were fertilized by such spermatozoa.
Prenatal development of the retina in a diurnal primate (Macaca mulatta)
Authors: Keefe J. R. , Ordy J. M. , Samorajski T. 
Published: February 2005

AbstractObservations were made on the pre‐ and postnatal development of the photoreceptors in the central region of the retina in the diurnal rhesus monkey. Histologic findings on the level of development of the retina at birth revealed a macula with the characteristic adult foveal depression. Observations on the ultrastructural development of the receptor inner and outer segments revealed that the photoreceptors were well differentiated even at birth. An evaluation of the prenatal morphogenesis of the photoreceptors indicated that the initial differentiation may take place as early as 100–125 days after conception. At 100 days after conception, the pigment epithelium consisted of a single layer of cuboidal cells with cytoplasmic content of smooth endoplasmic reticulum, but was only sparsely populated with mitochondria and rough endoplasmic reticulum. The photoreceptor inner segments contained vesiculation in the supranuclear region, while the incipient outer segments consisted of outbudding ciliary processes. By 125 days postconception, the pigment epithelium contained such cytoplasmic specializations as increases in rough endoplasmic reticulum and mitochondria, as well as greater organelle complexity. In the photoreceptor outer segments there were arrays of closed bimembranous discs, with vesiculation at the apical tip in the inner segments. A comparison of the pre‐ and postnatal ultrastructural changes in the choroid and the interstitial zone comprising the photoreceptor outer segments and the cell processes of the pigment epithelium suggested that the changes in these areas represent a critical aspect in the maturation of the retina.
Electron microscopy of erythropoiesis in the avian yolk sac
Authors: Edmonds Richard H. 
Published: February 2005

AbstractThe formation of the first blood cells which develop in the area vasculosa of the chick embryo have been examined to seven days of incubation. Angioblasts have been seen to arise from the mesoderm and to give origin to the first endothelium and intravascular blood islands. This occurs as the intercellular spaces enlarge and coalesce. The angioblasts and blood islands are not syncytial but are held in close relation by attachment areas and cytoplasmic processes. Two cell types arise concurrently from the blood islands, a stem cell and cells which have begun their differentiation into the primitive red cell series. The morphological events associated with this differentiation are similar to those in other hematopoietic organs. The definitive series of red blood cells arises from the stem cells at 4 to 5 days of incubation. The morphological differentiation of the definitive red cell is generally similar to that of the primitive series although the late and mature stages show structural differences. Nuclear structure, relation of interchromatin material to nuclear pores and the presence of marginal bands in the definitive series allow a differentiation between the two series.Granulocytes arise from extravascular stem cells at about five days of incubation but at seven days are not fully mature or abundant.Limited observations on the avian thrombocyte are reported.
Cytology of the fetal zone of the adrenal gland of the armadillo
Authors: Enders Allen C. , Schlafke Sandra , Warren Robert 
Published: February 2005

AbstractThe fine structure of the adrenal gland of the fetal armadillo was examined by electron microscopy to determine whether or not there were two cell types in the parenchyma of the fetal zone, as suggested by examination by light microscopy, and whether any of the cells of this zone had the cytological features associated with steroid production.Two cell types were found. One cell type is composed of large cells situated in clusters and containing a relative paucity of organelles. The other cell type is composed of smaller, eosinophilic, PAS positive cells, situated primarily in a reticular pattern around the blood vessels. This second cell type has numerous spherical mitochondria with tubular cristae and an extensive tubular agranular endoplasmic reticulum. It is concluded that this latter cell type is responsible for the steroid production reported by other authors. Both of the cell types of the fetal zone appear to be derived from the original mesenchymal blastema of the adrenal gland.
Cerebral cell population under hypoxia
Authors: Shivers Richard R. , Roofe Paul Gibbons 
Published: February 2005

AbstractThree pregnant albino Sprague‐Dawley rats were subjected to simulated high altitudes of 18,000 feet (365 mm Hg) in low pressure chambers during their entire pregnancy. The brains of the newborn rats were removed immediately after birth and placed in 10% formalin. The brains were sectioned, stained, and analyzed for changes in the number of cells in the cerebral cortex of the frontal lobes. An equal volume of control material was similarly prepared and analyzed. A volume of tissue of about one‐fourth cubic millimeter was used in the control and in the experimental tissue. The results indicated a 19.29% increase in the number of cells in the frontal cortex of newborn rats subjected to simulated high altitude anoxia. This increase is believed to be due to a proliferation of glial elements in the areas of the cortex which were studied. The cell hyperplasia seen here may be a response to physiological stresses placed upon the fetus by maternal anoxia.
A modified Golgi‐Cox method with counterstain for the study of synapses
Authors: Ha Hongchien 
Published: February 2005

AbstractThe method described was found especially valuable for the study of synaptic connections and unimpregnated cells. Brains and spinal cords of the young cat, dog and frog were fixed by perfusion with gum acacia saline and formalin. The brains and spinal cords were removed and immersed in 10% formalin in saline for two weeks or more. Tissues were sliced into blocks 3 mm thick, washed and impregnated in a modified Golgi‐Cox solution for from 6 to 8 weeks. Parlodion sections of 80 μ to 100 μ thick were treated with 5% ammonium tetroxide and counterstained with 0.25% cresyl fast violet. The sections were then differentiated in 95% alcohol, dehydrated, cleared and mounted. The method tends to prevent shrinkage, promote staining of axons, terminals and synapses and stains unimpregnated neurons.
Lipoprotein in the normal and regenerating limb tissues of the adult newt, Diemictylus viridescens
Authors: Schmidt Anthony J. 
Published: February 2005

AbstractLipids tightly bound to cell and tissue proteins (lipoproteins) were investigated with the acetone‐sudan procedure in cryostat‐cut sections of normal and regenerating limb tissues of the adult newt, Diemictylus viridescens.Nuclear and cytolplasmic membranes of all tissues stained moderately black; the nucleo‐ and cytoplasm stained less intensely than their membranes. Connective tissue fibers of the dermis, mysial and neural sheaths, and tunics of blood vessels yielded intense responses. In striated muscle of the limb, myofibrils and associated striations responded strongly. Nerve myelin responded weakly.In the preblastemic regenerate, the fibrous adepidermal basement membrane terminated abruptly at the surface of amputation. A distal fibrocellular residue was evident in continuity with the retrograde degeneration of amputation‐injured muscle: observations suggest a possible contribution to the fibrocellular reticulum from myofibrils. The regeneration blastema appears isolated from proximal limb tissues by the intervening fibrocellular reticulum. The response of the blastema cell is relatively weaker than that of other cells and tissues. Regenerating muscle is recognized by the appearance of prominently stained myofibrils in myoblastic extensions off the limb stump musculature. The matrix and chondrocytes of regenerating cartilage stain for lipoprotein, with the osteoid of osteogenic centers responding strongly.Polychrome responses were obtained from hyalin‐bodies within interphase nuclei, and from chromosomes in mitosis, suggesting that chromosomal lipid has been stained.Supporting the lipidic character of the observed responses is the negative reaction following long term lipid extraction in warm chloroform: methanol.
Gross structure of the ear, nasal cavity and Paranasal sinuses of the chimpanzee
Authors: House E. L. , Pansky B. , Jacobs M. S. , Wagner B. M. 
Published: February 2005

AbstractGross examination of the chimpanzee skull revealed that: there are three ethmoidal sinuses; the sphenoid sinus is immense and is divided into a superior and inferior part; the huge maxillary sinus contains a distinct bony canal for the nasolacrimal duct; the anterior and middle ethmoidal sinuses drain into the superior meatus; the frontal sinus drains via the middle ethmoid; the posterior ethmoid and sphenoid sinuses open into the sphenoethmoidal recess and also communicate with each other; the maxillary sinus opens into the middle meatus through a large ostium; the nasolacrimal duct drains into the inferior meatus; the mastoid process is small but contains a central cavity which communicates with the middle ear; the broad and smooth planum tympanum serves as the floor of the external auditory canal, the latter forming an angle of 30° with the horizontal; the tympanic membrane makes an angle of 30° with the floor of the canal and is deeply recessed antero‐inferiorly; except for the extreme slope of the tympanic membrane and the malleus, the middle ear is similar to man; the inner ear is likewise similar; the carotid artery and the large carotid plexus lie in a definite osseous tube surrounded by pneumatized bone but attached to the periotic capsule; the chimpanzee is subject to otitis media.
Leucocyte‐like cells of the vagina and uterus, and their modification during the normal estrous cycle and by progestin and estrogen treatment
Authors: Nellor John E. , Brown Joan E. 
Published: February 2005

AbstractExaminations of genital tract tissues and vaginal smears of normal cycling and progestin and estrogen treated cattle, sheep, and swine suggest that the majority of leucocyte‐like cells appearing in the tissues and smears of non‐infected animals are not of immediate blood origin, but originate from undifferentiated genital tract mesenchymal cells. During the luteal phase of the cycle, or during progestational treatment, plasma cells are produced in great numbers. They penetrate the stroma, epithelium, and lumen of the vagina as intact cells. Shortly after their entry into the vaginal lumen, they appear similar to polymorphonuclear leucocytes, as the result of dissolution of the nuclear membrane and scattering of the wedge‐shaped nuclear masses throughout the cell. The relative paucity of leucocyte‐like cells in the vaginal smear close to the time of ovulation results from interruption of the migration and differentiation of the plasma cells within the genital tissues, by estrogen induced fragmentation of the plasma cells. Eosinophilic polychromatin fragmenting plasma cells account for the majority of eosinophilic leucocytes in healthy genital tract tissues during proestrus and estrus.
Effects of cortisone acetate upon hydration of embryonic palate in two inbred strains of mice
Authors: Jacobs Richard M. 
Published: February 2005

AbstractAn absolute and relative loss of water was recorded in 169 palates derived from the offspring of cortisone treated and control mice. Experimental sample consisted of 38 time‐pregnant females of A/Jax and C57BL inbred strains. Animals were killed on thirteen and one‐third, fifteen and one‐third or eighteen and one‐third day of gestation and the fetuses were removed by laparotomy. Palatine shelves were dissected, weighed, desiccated and weighed again, under standardized conditions. The results tend to confirm the hypothesis that cortisone‐induced mechanical incompetence of embryonic palate may be associated with disturbed water metabolism and diminished cohesion of the tissues. It has been proposed that the observed differences of response of each strain to teratogenic and palatal edema‐inducing action of cortisone may be based upon genetically controlled metabolic polymorphism which determines the pathway of cortisone biotransformation and decay in the tissues.
The fine structure of the thrombocyte in the dogfish (Mustelus canis) with special reference to microtubule orientation
Authors: Shepro David , Belamarich Frank A. , Branson Roger 
Published: February 2005

AbstractThe cytoplasm of the dogfish (Mustelus canis) thrombocyte was found to contain microtubules. The tubules which measured 230 Å in diameter appeared singly and in groups. They were found in all parts of the cytoplasm but usually close to the perinuclear area. Similar arrangements of tubules were observed in eosinophils and hemoblasts, but not in the mature, smaller lymphocytes. The orientations of the perinuclear bundles frequently reflected the shape of the nuclei, appearing in furrows, indentations, and between lobes.
Weight changes of the submandibular glands in the rat resulting from denervation
Authors: Martin William D. , Smith R. Dale 
Published: February 2005

AbstractIn the lingual nerve of the rat, the number of myelinated fibers ranged from 3,215 to 3,744, with diameters ranging from 0.7 to 9.7 μ. The nerves were unimodal with a peak at 2–3 or 3–4 μ. In the chorda tympani, the number of myelinated fibers ranged from 444 to 538, with diameters ranging from 1.1 to 8.7 μ. The nerves were unimodal with a peak at 1–3 μ.Sixteen days after section of the lingual, chordalingual (the lingual nerve distal to the union with chorda tympani) and chorda tympani nerves as well as intracranial section of the facial nerve, significant weight losses were recorded for the submandibular and retrolingual glands. The greatest weight losses occurred after intracranial section of the facial nerve or section of the chordalingual nerve (retrolingual glands lost 42 and 39%, submandibular glands lost 20 and 28% respectively). Intracranial section of the facial nerve demonstrates that the degree of weight loss is correlated with the number of myelinated fibers (1–3 μ diameter) which degenerate, and that the weight loss is not the result of operative damage to the vascular supply of the glands.
Cytoplasmic microtubules in mammalian erythropoietic cells
Authors: Grasso Joseph A. 
Published: February 2005

AbstractElectron microscopic examination of rabbit erythroblasts revealed the presence of microtubules, 210–270 Å in diameter, composing a marginal band in the cell periphery. This band was composed of 6–8 microtubules arranged more or less parallel to one another. Transverse sections indicated that 16–18 tubules may comprise the band. The latter appeared to be poorly formed or absent in reticulocytes and erythrocytes. Microtubules were also found in the deeper regions of the cytoplasm as well as composing th emitotic spindle of dividing erythroblasts. With the exception of the procentriole and the asters and chromosomes of dividing cells, microtubules were not continuous with other organelles. The function of the marginal band is interpreted as imparting elasticity and resiliency to the cell, a cytoskeleton responsible for maintenance of cell form. “Coated” micropinocytotic vesicles in erythroblasts, hepatocytes, and reticulo‐endothelial cells are also described. Most of the “coated” vesicles in erythropoietic cells did not contain ferritin. It is suggested that, in the “coated” vesicles, ferritin may be in a highly dilute form or, alternatively, that its relative absence may indicate that iron is obtained predominantly through the plasma transferrin system rather than through incorporation of iron in the form of ferritin.
Derivation of the vascular elements in the fetal cotyledon of the hemochorial placenta: A contribution to the theory of placental morphogenesis
Authors: Reynolds S. R. M. 
Published: February 2005

AbstractA schematic plan of late developmental organization of the fetal cotyledonary elements of the hemochorial placenta is presented. It involves mechanical shaping by hemodynamics and stretching of the elements involved in the late chorion frondosum stage after the 2nd month of gestation. The result is the fetal cotyledon as described by Wilkin. The components of the fetal cotyledon are derived from differentiated vascular elements in tertiary stem, or anchoring, villi and vascular elements of the blastoderm which are formed by the twenty‐first day after ovulation.
Localization of the neural control of luteinization in the feminine male rat (FALE)
Authors: Gorski Roger A. 
Published: February 2005

AbstractCastration of the male rat during the first three days of life allows retention of the cyclic pattern of gonadotrophin release with which the male is born. Since the neonatally castrated male shares several endocrine characteristics with the female, the terms feminine male or FALE have been employed to identify these animals. Twenty‐seven of 28 FALES developed corpora lutea (CL) in ovarian transplants provided no other treatment was initiated. In contrast, exposure to constant illumination, suprachiasmatic lesions, or transection of anterior hypothalamic pathways prevented CL formation in 18 of 20 FALES. These findings support the concept that the preoptic‐anterior hypothalamic region is an essential component of the neural mechanism which regulates the cyclic luteinization of ovarian grafts in the FALE. Since the FALE is a male rat in which differentiation has not been permitted to occur, it is suggested that sexual differentiation of the normal male hypothalamus consists of an alteration in function of this preoptic system.
Relation between the size of ovarian isografts and abnormal reproductive cycles in the mouse
Authors: Browning Henry C. , White Wilma D. 
Published: February 2005

AbstractGroups of 10 to 14 castrated female BALB / c mice received viable uni‐ or bilateral intraocular isografts of one‐eighth or of one‐thirty‐second of an ovary. Ten other animals remained intact. At biopsy five months later, the mammary glands of all animals showed little or no stimulation. Most animals with one or two one‐eighth or two one‐thirty‐second, grafts had shown normal vaginal and ovarian cycles prior to this time, but some had been in continuous metestrus and had acyclic grafts with vesicular follicles. Most animals with one one‐thirty‐second grafts were similarly in metestrus, but some were in diestrus with grafts lacking follicular structures. At autopsy eight months after grafting, almost all mice with one or two one‐eighth grafts had alveolar proliferaiton with secretion in the mammary glands. All were in continuous metestrus with acyclic grafts, and most had uterine cystic hyperplasia and peri‐medullary adrenal degeneration. At the same time, slightly more and slightly less than a half of the mice with one or two one‐thirty‐second grafts, respectively, showed these same abnormalities. Intact mice were devoid of them. The development of this mammary‐uterine‐adrenal syndrome appeared to be directly related to grafted ovarian tissue per se and to the size of the grafts. It may depend upon a pituitary‐ovarian imbalance with a failure of LH release.