bluuebunny/crossref_metadata_2025_split huggingface dataset:
The cartilage endplates of the human vertebral column (some considerations of postnatal development)
Authors: Donisch E. W. , Trapp W. 
Published: February 2005

AbstractThe cartilage plates covering the lumbar vertebral bodies were examined macro‐ and microscopically in infants and children. Particular attention was given to the distribution of vascular canals within these plates. Some of the canals are responsible for the formation of spoke‐like ridges of cartilages. The latter develop as the vertebral body expands in height and girth. The canals show a characteristic distribution and end blindly in the neighborhood of the anulus fibrosus.The cartilage plates are known to provide a growth zone for the center of the vertebrae. In addition, they appear to contribute also to the growing intervertebral disc. The present investigation suggests that an association exists between the blind endings of the vascular canals and the interstitial lamellar growth of the anulus fibrosus at the time of active, postnatal disc expansion.Comparison of differences in shape of infantile lumbar vertebrae were made in various cases with a known history. These studies suggest that weight bearing and movement influence the development of a particular shape. It can be demonstrated that in the absence of normal stresses some lumbar vertebrae grow taller and have a decreased anterior‐posterior diameter.
Fine structural study on the origin and development of the sphincter pupillae muscle in the West Coast newt (Taricha torosa)
Authors: Tonosaki Akira , Kelly Douglas E. 
Published: February 2005

AbstractThe origin and development of the sphincter pupillae muscle was studied in Taricha torosa by electron microscopy. The larval optic cup with its inner and outer epithelial layers is completely enshrouded by a primary basal lamina. The epithelium can be divided into E and R regions, according to the types of distributed pigment granules, ellipsoidal (E) and round (R). The E region includes the outer layer except the pupillary zone; the R region the inner layer and pupillary zone. The boundary dividing these regions is distinct enough to be called the E‐R boundary. Clusters of fine filaments develop in the pigment‐containing R cells adjacent to the E‐R boundary during metamorphosis. Such R cells subsequently increase their population to form abundle swelling into the anterior ocular chamber. This bundle formation is accompanied by acquisition of a nerve supply from the iridial stroma, and the emergence of collagen fibers as well as secondary basal (or external) laminae surrounding each cell of the bundle. The adult muscle cells retain numerous round pigment granules, desmosomes, and intermediate junction.These facts support the neuroectodermal origin of this sphincter pupillae muscle.
The uptake of tritiated thymidine by the dorsal epidermis of the fetal and newborn rat
Authors: Stern I. B. , Dayton L. , Duecy J. 
Published: February 2005

AbstractThe dorsal epidermis of fetal and newborn rats was examined to determine the difference in ability of the basal cells to bind tritiated thymidine during different stages of epidermal morphogenesis. Five rats were examined for each time period from the eleventh day of gestation to the fifth day after birth. The number of labeled cells in 5000 basal cells was counted and expressed as a percentage. The labeling index is ∼ 10% from the eleventh to the fifteenth fetal day. It increases to ∼ 30% by the eighteenth day, decreases to ∼ 10% from the twenty‐first day until the first postpartum day and drops to 5% or less from the second to fifth day. These changes in labeling index are accompanied by and apparently correlated with the normal differentiation of rat epidermis. The growth of the epidermis is continuous during the course of the study. Keratohyalin granules begin to form on the eighteenth day and by the twentieth day the first cornified cells appear. The s. corneum becomes progressively thicker each day thereafter. The s. Malpighii, on the other hand, decreases somewhat in thickness after birth. The labeling index curve represents a relationship between basal cell activity and control or influencing mechanisms inherent in the maturational system of skin. The increase and decrease are not related to growth alone, but appear to be related to differentiation.
The Function of the teres major muscle: An electromyographic study
Authors: Broome H. L. , Basmajian J. V. 
Published: February 2005

AbstractElectromyographic activity of the teres major and latissimus dorsi muscles using indwelling bipolar fine‐wire electrodes was recorded during motion of the arm and shoulder without resistance, against resistance, and during static resisted activity. The teres major is active during static motion and during motion against resistance with medial rotation, adduction, and extension of the arm. It is not active during motion without resistance, although latissimus dorsi usually is.
Fine structure of the Leydig cell during postnatal differentiation of the mouse testis
Authors: Russo J. 
Published: February 2005

AbstractIt is possible to divide the ultrastructural events which take place in the mouse Leydig cell during postnatal differentiation into two periods. The first period includes the changes taking place during the first three weeks after birth, whereas the second period comprises the events occurring from the fourth week on. During the first period the cytoplasm contains a poorly developed smooth endoplasmic reticulum. After the tenth day a slight increase in the number of vesicles and tubules of the smooth endoplasmic reticulum is observed. Clusters of glycogen particles (beta type) and lipid droplets are very numerous in this period.At the beginning of the second period the smooth endoplasmic reticulum hypertrophies considerably occupying a large area of the cytoplasm. This period is also characterized by the appearance of double‐walled tubules, of numerous interdigitations between neighboring Leydig cells and primary lysosomes in close relation to lipid droplets. A marked decrease in the number of glycogen particles and lipid droplets are also found. In the adult mouse (after day 50) numerous cisternae of the smooth endoplasmic reticulum are concentrically arranged (whorls).The formation of new membranes in the Leydig cell undergoing differentiation and the control of such differentiation are discussed.
Intertubular circulation in the opisthonephric kidneys of adult and larval sea lamprey, Petromyzon marinus L.
Authors: Youson John H. , McMillan Donald B. 
Published: February 2005

AbstractThe opisthonephric kidneys of both larval and adult Petromyzon marinus lack a renal portal system. The tubules are supplied with arterial blood from the glomus through a system of efferent arterioles, capillaries, and sinusoids with the latter draining into the venous system. The adult kidney possesses a more complex and larger system of sinusoids than ammocoetes and these sinusoids reach the venous system through large subcapsular sinuses. Paralleling of tubules with sinusoids and arterioles in the ventral portion of the adult kidney resembles the association of the vasa recta with the tubules of the renal medulla in the mammalian kidney. This may suggest a mechanism important to tubular transport in adult lampreys. The intertubular tissue of ammocoetes is infiltrated with haemopoietic tissue while large numbers of phagocytes within the adult sinusoids may be involved in the destruction of blood cells.
Cell count correction factors for the quantitative histological analysis of the germinal epithelium of the ram
Authors: Lino Barry F. 
Published: February 2005

AbstractThe relationship between the Sertoli cell counts, some measurable parameters of the seminiferous tubules and the dimensions of the Sertoli cell nuclei were examined in both normal and degenerate testes. Highly significant differences were found between rams in the numbers and in the dimensions and volumes of the Sertoli cell nuclei and in the diameters of the seminiferous tubules. The Sertoli cell counts were corrected for the differences in nuclear volume by dividing the count by the calculated nuclear volume. The Sertoli cell counts were corrected for changes in the area of the seminiferous tubule wall by multiplying the count by the square of the tubule radius. Correction for either nuclear volume or tubule area alone increased the differences between the Sertoli cell counts, but a simultaneous correction for both factors equalized the counts so that there were no significant differences between rams in the number of Sertoli cells per tubule cross‐section. It was concluded that, in normal and degenerate ram testes, counts of the Sertoli cell nuclei in the seminiferous tubule cross‐sections, when corrected for differences in nuclear volume, would provide a valid basis for comparing volume‐corrected counts of spermatogenic cells in different animals and in different treatments.
Epithelial cell proliferation in the mouse vagina during the estrous cycle, pregnancy and lactation: A radioautographic study
Authors: Traurig Harold H. 
Published: February 2005

AbstractA radioautographic study of epithelial cell proliferation in the vaginas of mice during the estrous cycle, pregnancy, lactation, and under certain experimental conditions is reported. Data were expressed as labeled cells per 1000 basal cells counted. The proportion of labeled cells that were basal or nonbasal was determined. The highest rates of proliferation were recorded during the estrous cycle, specifically during late diestrus, proestrus and early estrus. During pregnancy the rates of proliferation increased from metestrous levels beginning on day three and reaching a maximum on day 4 just before implantation, followed by a decrease on days 6 and 8. There was an increase on day 12 followed by a more marked increase on day 19, the last full day of pregnancy. On the first day post partum the rate of proliferation was very low. A small increase followed during early lactation.Data on rates of vaginal epithelial proliferation were used to infer the estrogen secretion pattern during reproduction in the mouse. In addition it was concluded that progesterone augmented the proliferative response of the vaginal epithelium to estrogen, specifically promoting proliferation of nonbasal cells. Experiments using mated, castrated mice and estrogen or progesterone replacement confirmed these conclusions.Data and conclusions are discussed relative to recently reported data on ovarian plasma estrogen and progesterone content in rats during reproduction.
The fine structure of a lateral recess of the subarachnoid space in the rat
Authors: Himango William A. , Low Frank N. 
Published: February 2005

AbstractThis study reports an electron microscopic investigation to the spinal meninges of the rat as they exist between the dorsal and ventral nerve roots in upper thoracic and cervical levels of the vertebral column. Between these roots, at a point where they penetrate the spinal dura, the leptomeninges are characterized by a histological pattern comparable to that elsewhere comprising the subarachnoid angle. However, this region is modified and possesses a number of heretofore unknown histological features. The most noteworthy is a lateral recess of the subarachnoid space.The meninges located between the nerve roots do not form a definite lateral boundary for the subarachnoid space. Here the subarachnoid space opens into a lateral recess which extends peripherally between the dorsal and ventral nerve roots. Conspicuous amounts of cellular debris are collected within the lateral recess. Numerous free macrophages congregate here. The lateral recess may be a communicating pathway between the central and peripheral nervous systems by way of the endoneurium of the nerve trunk.
Weight standards for organs from early human fetuses
Authors: Tanimura T. , Nelson T. , Hollingsworth R. R. , Shepard T. H. 
Published: February 2005

AbstractOne hundred and thirty‐six unfixed fetuses below 500 gm of body weight were examined and the brain, liver, lung, kidney, heart, adrenal, thymus, spleen, and thyroid were weighed. The ratios of organ weight to body weight could be divided into four general patterns: (1) constant; liver, heart, brain, and thyroid (2) increasing; thymus, adrenal, and spleen (3) initially increasing and then reaching a plateau; kidney, and (4) increasing and then decreasing; lung. Graphs of the mean and 95% confidence levels along with the formulas used for derivation are given for each organ on the basis of body weight.
The isolated mucosa of turtle bladder
Authors: Lefevre M. E. , Gennaro J. F. , Brodsky W. A. 
Published: February 2005

AbstractThe mucosa of the turtle bladder was separated from underlying tissue by blunt dissection and its composition characterized. Although large amounts of non‐epithelial tissue were removed by the dissection, a considerable amount of connective tissue and a small amount of smooth muscle were always present in the isolated layer. The epithelial cells were described and anatomical features of significance in water and ion transport studies examined. The columnar epithelial cells of the mucosal layer were arranged in clusters bounded by crypts. The cells were larger near the bladder neck than in the distal regions of the bladder. Single smooth muscle cells were found immediately beneath the epithelial cell layer. Long intercellular channels separated the cells. Possible roles of these features in water and ion transport were discussed.
Cytological differentiation of the mesothelial cells of the yolk sac of the bat, Tadarida brasiliensis cynocephala
Authors: Stephens Robert J. , Cabral Linda J. 
Published: February 2005

AbstractAn ultrastructural analysis of the mesothelial cells of the yolk sac of the bat throughout gestation is presented. At first these cells are closely associated with the cytotrophoblast but become displaced by action of the allan‐tois and collapse of the yolk sac. The mesothelial cells are exposed to the exo‐coelom and develop cytological features characteristic of absorptive cells. Among these features are: (1) long microvilli extending from the apical and lateral plasma membranes and (2) absorptive canaliculi and tubules as well as absorptive vacuoles in the superficial cytoplasm. There is a paucity of mitochondria and rough endoplasmic reticulum throughout the existence of this cell type. After midgestation, granules containing numerous crystalloids appear in the cytoplasm of most of the cells. These are apparently the result of the absorption of protein‐aceous material from the exocoelom. The crystalloids disappear before birth, and the mesothelium becomes degenerative in appearance. This sequence of development of the cytological features suggests a dynamic role for the mesothelium throughout its existence that involves absorption and storage of proteinaceous material from the exocoelom for use by the embryo.
Ruthenium red and violet. II. Fine structural localization in animal tissues
Authors: Luft John H. 
Published: February 2005

AbstractThe inorganic dye, ruthenium red, stains extracellular materials in animal tissues which probably are acidic mucopolysaccharides. It complements other techniques, its advantages being fine grain, high resolution and good contrast. Localization is shown in mouse and rat muscle, heart, lung and intestine, frog cartilage and cells scraped from oral epithelium of human beings. Attention is paid to collagen bundles, the cell/collagen interface and particularly the myotendinal junction, cartilage matrix and agar gel, desmosomes, intestinal microvilli, erythrocytes and vascular endothelium, nerve fibers and the T‐system of striated muscle. Although ruthenium red generally is excluded by plasma membranes, it penetrates giving intracellular density, if the membrane is broken. Even when the cell membrane is intact, exceptions occur with selective staining of the T‐tubules or the sarcoplasmic sacs depending upon the state of contraction of the muscle cell, and with intracellular staining of certain nuclei and epithelial cells. Ruthenium red stains intracellular lipid droplets revealing lamellae, and stains myelin forms grown from crude egg lecithin but cannot penetrate deeply. It is localized in extracellular materials which have an important mechanical function. Its exclusion by cell membranes permits tracing tortuous cellular invaginations and those exceptions to its exclusion invite a comparison of the localization of the dye with the function of the cell.
Ultrastructural studies on elastic fibers using enzymatic digestion of thin sections
Authors: Daniel Bodley H. , Wood Richard L. 
Published: February 2005

AbstractThe enzymes elastase, chymotrypsin, pepsin, pronase, hyaluronidase, and collagenase were utilized on thin Epon sections to obtain further information on the nature of elastic fibers. Results showed that the central amorphous material was selectively removed by elastase and after hydrogen peroxide pretreatment it also was removed by chymotrypsin, pepsin and pronase. None of the enzymes removed the peripheral microfibrils, but pepsin did accentuate the density and periodic beading of these structures. The failure of proteases to remove the microfibrils under these conditions is discussed.
Temporary lobulation in cartilagenous models of long bones
Authors: Miller Marian L. , Basom Charles R. , McCuskey Robert S. 
Published: February 2005

AbstractVascular patterns and the vertical zones of maturing cartilage cells are arranged in geometric radiations. This lobular arrangement reflects a distribution of cells and matrix of differing maturity; those cells and matrix closest to the collagenous wall of the vascularized canal are maintained in an immature state longer than those located toward the periphery of the lobule. This configuration suggests a relationship between the oxygenation of cartilage, its maturity, and its ossification. Arteries in the cartilage canal frequently are destined to become the arteries located within themarrow cavity of mature bones.
The nature of endochondral ossification in the mandibular condyle of the mouse
Authors: Silbermann Michael , Frommer Jack 
Published: February 2005

AbstractThrough the application of histological and histochemical techniques, this study demonstrates that the ossification process of the mandibular condyle differs basically from that of other endochondral growth sites. In the epiphyseal plate of a typical long bone, the cartilage cells are known to undergo degenerative processes and death. In the mandibular condyle, however, the cartilage cells keep their vitality throughout the cartilage zones. In the lower border of the calcified cartilage, adjacent hypertrophic cartilage cells fuse after the dissolution of the intervening matrix to form multinuclear chondroclasts. These giant cells reveal marked positive reaction to mitochondrial and lysosomal enzymes. It is suggested that these enzymes are active in the resorption process of the calcified cartilage matrix, which is an integral phase of the ossification mechanism of the condylar growth center. It is believed that the mandibular condyle of the mouse demonstrates a specific type of endochondral ossification, in which the hypertrophic chondrocytes are not dying cells, but contribute actively to the process of bone formation.
Cartilage canals, their morphology and distribution
Authors: Wilsman Norman J. , Van Sickle David C. 
Published: February 2005

AbstractThe proximal humeral chondroepiphysis of newborn pups was shown to be well‐vascularized by a series of segmentally distributed cartilage canals which varied from short unbranched channels to channels which coursed half‐way across the epiphysis. Cartilage canals were observed to contain a muscular arteriole, venule, loose connective tissue and perivascular capillaries. The muscular arterioles originated from the dense perichondrial vascular network at regular intervals, coursed in the central portion of the cartilage canal, and terminated by dividing into a capillary glomerulus in the cartilaginous matrix.These glomeruli were observed to assume a wide variety of sizes and shapes reflecting the metabolic needs of the areas they served. The capillaries of the glomerulus recombined into a single venule which rejoined the perichondrium via the same channel as the parent arteriole. The loose connective tissue surrounding these vessels was rich in fibroblasts and macrophages and was continuous with that of the perichondrium.From the structural relationship of the cartilage canals and the articular surface, it was concluded that at birth the synovial fluid had little nutritional significance for the epiphysis, but with age the nutritional contribution from the synovial fluid became more important.The particular arrangement of the venule and the perivascular capillaries allowed for metabolic exchange the entire length of the canal. Structures which appeared to be unmyelinated nerves and structures which contained a flocculent material and resembled lymphatics were seen in the connective tissue of the cartilage canals.
Hormonal regulation of the “fatted” phenomenon in squirrel monkeys
Authors: Nadler Ronald D. , Rosenblum Leonard A. 
Published: February 2005

AbstractThe hormonal basis of the ‘fatted’ phenomenon in squirrel monkeys was investigated by gonadectomy and androgen treatment of adult males and females. Significant correlations were found between testis weight and body weight and between testis weight and the sharp reductions in body weight that occurred following gonadectomy. of the males. Females lost little, if any weight, following gonadectomy. Androgen treatment of male castrates resulted in increased body size, weight and physical appearance, closely approximating the condition reported to occur in normal males during the mating season. Female castrates responded to androgen treatment with an analogous development of‘fattedness.’ The data suggest that the ‘fatted’ condition observed seasonally in the field is regulated by fluctuations in endogenous androgen levels of males and that females share that characteristic responsiveness to androgen.
Transmission of an ‘osteogenic message’ through intact bone after wounding
Authors: Melcher A. H. , Accursi G. E. 
Published: February 2005

AbstractWounds ˜ 1 mm wide were made in the middle third of the spine in both scapulae of 25 middle‐aged Wistar‐strain rats weighing ˜ 500 gm. Wounding of the body of the scapula was avoided. Some of the animals were injected with tetracycline, and sections from their scapulae were viewed in ultraviolet light. After one or more weeks of healing, bony callus was deposited on the dorsal surface of the blade of the scapulae in the vicinity of the wounds. Discrete deposits of bony callus were also deposited on the corresponding costal surface of the blade of the scapulae. These deposits, which were in no way connected with those on the dorsal surface, did not exhibit continuity with the wound in the spine. This observation has been interpreted as suggesting the passage of an ‘osteogenic message,’ whose nature can only be guessed, from the vicinity of the wound on the dorsal surface of the scapula to the corresponding costal surface. Lacunae of osteocytes in the scapulae, lying deep to periosteal and endosteal callus, fluoresced. This suggests that these osteocytes were activated by the trauma, and deposited mineral salts on the walls of their lacunae.