bluuebunny/crossref_metadata_2025_split huggingface dataset:
A comparison of methods for measuring cortical bone thickness
Authors: Chumlea W. Cameron , Mukherjee Debabrata , Roche Alex F. 
Published: May 2005

AbstractRepeated measures of periosteal and endosteal widths of the left second metacarpal from two samples of radiographs were made independently with either a dial caliper or an electronic digitizer connected to a microcomputer. In addition, periosteal and endosteal bone widths of a common sample of radiographs were measured with dial calipers and the electronic digitizer. Dial calipers and an electronic digitizer are both very reliable, but intraobserver errors produced with the use of the digitizer are significantly less than those produced with the use of dial calipers. However, measurements made with the electronic digitizer are systematically larger than corresponding widths measured with dial calipers, but this difference is very small.
Sperm/egg interaction: The specificity of human spermatozoa
Authors: Bedford J. M. 
Published: May 2005

AbstractHuman spermatozoa display unusually limited affinities in their interaction with oocytes of other species. They adhered to and, when capacitated, penetrated the vestments of the oocyte of an ape‐the gibbon, Hylobates lar‐ both in vivo and in vitro. On the other hand, human spermatozoa would not even attach to the zona surface of sub‐hominoid primate (baboon, rhesus monkey, squirrel monkey), nor to the non‐primate eutherian oocytes tested. Among the apes the gibbon stands furthest from man. Thus, although the specificity of human spermatozoa is not confined to man alone, it probably is restricted to the Hominoidea. This study also suggests that the evolution of man and perhaps the other hominids has been accompanied by a restrictive change in the nature of the sperm surface which has limited and made more specific the complementary surface to which their spermatozoa may adhere. For the failure of human spermatozoa to attach to the zona surface of all non‐hominoid oocytes stands in contrast to the behaviour of spermatozoa of the several other mammals studied which, in most combinations, adhered readily to foreign oocytes, including those of man. Taxonomically, the demonstration of a compatibility between the gametes of man and gibbon, not shared with cercopithecids, constitutes further evidence for inclusion of the Hylobatidae within the Hominoidea.
Trigeminal nerve endings in gingiva, junctional epithelium and periodontal ligament of rat molars as demonstrated by autoradiography
Authors: Byers Margaret R. , Holland G. R. 
Published: May 2005

AbstractTritiated‐L‐proline was injected into the right Gasserian ganglion of mature rats for incorporation into proteins being carried by rapid axonal transport to nerve endings. The distribution of the nerve endings in molar gingivae and periodontium was subsequently mapped in serial sections by autoradiography. We found that sensory nerve terminals are most prominent in two regions of the free gingiva: (1) In the junctional epithelium there is a rich innervation of the basal epithelial layer with many endings penetrating several cell layers. (2) In the crestal epithelium arborized endings are present, especially on the marginal side of the crest. In the attached gingiva a few terminals are found in the epithelium with more in the lamina propria; the latter appear to be encapsulated. The periodontal ligament is only moderately labeled with silver grains located over nerve bundles, over nerves associated with blood vessels, and over a few apparent endings in the apical region. In the cementum no labeled endings are seen. Labeling of Gasserian cell bodies primarily reveals specific intra‐epithelial nerve endings in gingival crest and junctional epithelium. The absence of major labeling of the periodontal ligament supports the view that many nerves in that region are derived from cell bodies in the mesencephalic nucleus.
Fine structure of the human synovial lining cell in osteoarthritis: Its prominent cytoskeleton
Authors: Meek William D. , Raber Brian T. , McClain Oza M. , McCosh Jeff K. , Baker B. B. 
Published: May 2005

AbstractThe cytoskeleton of the human osteoarthritic synovial lining cell (SLC) consists of an extensive number of vimentin intermediate filaments (IFs) in addition to microfilaments and microtubules. The IFs are especially prevalent in the SLC processes, but are commonly seen in a paranuclear arrangement. Processes, ending in numerous microvilli and blebs, project into the joint space. Scanning electron microscopy (SEM) further reveals the processes that may parallel the synovium surface for a short distance. IFs extend to the termination of such processes. Numerous pinocytotic vesicles and extensive rough endoplasmic reticulum (rER) are characteristic of the type B cells. Lysosomes and long microvilli identify the type A cell. Punctate adherens, gap junctions, and cilia are the cell membrane specializations of the osteoarthritis (OA) synovium. A comparison with synovium from rheumatoid arthritis (RA) patients is made in order to assess the effect of this inflammatory disease on the SLC cytoskeleton, cell type relationship, and cell arrangement. The prominent cytoskeleton appears to play an important role in the architecture of the synovium. Our findings are further presented in the form of a drawing which in some aspects could describe the morphology of the normal synovium.
Formation and release of vesicles from the basal surfaces of rat eye non‐pigmented ciliary epithelial cells: A novel secretory mechanism?
Authors: Eggli Peter S. , Graber Werner , Van Der Zypen Eugen 
Published: May 2005

AbstractWhen rat ciliary body is processed by high pressure freezing and freeze substitution, numerous membrane‐bound vesicle profiles are seen in the vitreous associated with the pars plana and in the valleys between the ciliary processes. They consist of a homogeneously distributed fine granular matrix and varying numbers of ribosome‐like structures. The mechanism by which these vesicles are secreted appears to follow an apocrine‐type pattern, albeit at the basal cell surface. Matrix material accumulates between the basal plasma membrane of non‐pigmented ciliary epithelial cells and a cortical layer of cytoskeletal components; the blebs thus formed protrude through a discontinuity in the basal lamina and, by a progressive narrowing of the neck region, are eventually pinched off, giving rise to free vesicles.Under conventional aqueous chemical fixation conditions, most of these vesicles are washed away or their contents solubilized and extracted, which accounts for their not having been identified hitherto as genuine morphological structures. They are nonetheless apparent, albeit in reduced numbers and mostly empty. Such vesicles are also observed in tissue processed according to several other chemical fixation techniques, namely, conventional fixation in the presence of the cationic dye ruthenium hexamine trichloride, simultaneous glutaraldehyde/osmium tetroxide fixation, and microwave fixation. In the latter instance, comparable vesicle preservation to that obtained by high pressure freezing/freeze substitution may be achieved if fixation is followed by cryoprotection, plunge freezing, and freeze substitution instead of conventional post‐fixation and dehydration procedures.
Cell and matrix biology of the suprapatella in the rat: A structural and immunocytochemical study of fibrocartilage in a tendon subject to compression
Authors: Ralphs James R. , Benjamin Michael , Thornett Andrew 
Published: May 2005

AbstractThe structure, ultrastructure, histochemistry, and immunohistochemistry of the suprapatella have been described in the rat. The suprapatella is a fibrocartilaginous sesamoid within the tendon of quadriceps femoris that articulates with the femoral condyles during flexion of the knee joint and reduces the amount of bending required at the tendon‐bone junction. The cells of the suprapatella were much larger and more numerous than those in the associated tendon and were packed with vimentin‐containing, intermediate filaments. The tendon cells contained far fewer filaments. The cells of both regions contained actin and tubulin. Histochemical and immunohistochemical studies showed that the suprapatellar cells were embedded in a matrix that is rich in chondroitin sulphate, but does not contain keratan or heparan sulphate. The fibrocartilage of the adjacent attachment zone of the quadriceps tendon also contained chondroitin sulphate, but in addition was rich in type II collagen. The structure of the suprapatella was similar to that of the fibrocartilaginous regions of tendons that pass around bony pulleys. However, there were differences in matrix composition that could reflect functional differences between the fibrocartilages.
Changes in ovarian morphology and serum hormones in the rat after treatment with dehydroepiandrosterone
Authors: Lee Mong‐Ting , Anderson Everett , Lee Gloria Y. 
Published: May 2005

AbstractThis investigation was designed to study ovarian and hormonal changes in the after treatment with dehydroeplandrosterone (DHEA). We identified a heterogeneous experimental group of animals with respect to ovarian histology: group I, corpora lutea (Cls) + cysts; group II, CLs + no cysts; group III, no CLs + cysts; group IV, no CLs + no cysts. Histological sections of these ovaries showed healthy and atretic follicles in different stages of cytomorphosis and degeneration. The aforementioned histological groups were also heterogeneous according to their hormonal profiles. Serum androgens, estrogens, and prolactin concentrations are significantly increased in DHEA‐treated animals as compared with controls. There was no significant difference in follicle stimulating hormone between the with cysts and rats without cysts after DHEA treatment. After 20 days of DHEA treatment, rats with CLs have very high levels of luteinizing hormone. Luteinizing hormone and prolactin levels are significantly higher in rats with cysts than in rats without cysts after 10 days of DHEA treatment. As has been shwon in this inquiry, androgens and estradiol levels in rats with cysts after DHEA treatment are higher than those in rats without cysts after DHEA treatment. Therefore, this study suggests that the ovarian cystic condition developed after DHEA treatment in rats, is associated with higher levels of circulating androgens, estradiol, and prolactin.
Morphometric study of the human neonatal ovary
Authors: Forabosco Antonino , Sforza Chiarella , De Pol Anto , Vizzotto Laura , Marzona Laura , Ferrario Virgilio F. 
Published: May 2005

AbstractA morphometric analysis, based on mathematical evaluations and stereological methods, has been used to study five left neonatal ovaries, removed from full‐term neonates with a 46, XX karyotype free from malformations of the genital apparatus.Each ovary was completely cut obtaining serial sections and one 1‐μ‐thick section every 1,000 μ was examined. Ovarian length ranged from 9 to 17 mm (mean 13 mm), width from 3.5 to 7 mm (mean 5.7 mm), thickness from 2.5 to 5 mm (mean 4 mm), and volume from 82.23 to 198.3 mm3 (mean 125.88 mm3). In the ovarian cortex, primitive cortical tissue accounted for 10‐20% of the total volume, follicles for 10‐25% and interstitium for 35‐45%; 10‐30% of the organ consisted of inner medulla. The total follicle number ranged from 130,000 to 385,000 per ovary, with an average of 266,000 with 95% being represented by primordial follicles. In all ovaries examined follicular growth was still in process, with follicles at different stages of development.
Immunochemical localization of extracellular materials in bone marrow of rats
Authors: Hamilton Rebecca , Campbell Ferrell R. 
Published: May 2005

AbstractThe distribution of type I collagen, fibronectin, laminin, and heparan sulfate was studied in marrow of rats by indirect immunofluorescence. Most of the type I collagen of marrow is associated with large blood vessels and connective tissue trabeculae, but type I collagen was also localized in a delicate meshwork throughout the marrow and in the basement membrane of the sinusoidal endothelium. Fibronectin is partially co‐distributed with type I collagen, but is much more widely distributed. Sheets or septa of fibronectin‐rich material divide the marrow into small compartments that contain and appear to separate clusters of developing blood cells. These septa may serve as a substrate for anchorage and migration of blood cells. Labeling of laminin was observed in the basement membranes of blood vessels, of fat cells, and of the sinusoidal wall, but only scattered labeling was seen in other extracellular materials. Heparan sulfate proteoglycan was poorly labeled in the extracellular matrix of marrow.
Organization of the membrane skeleton in spreading mouse blastomeres. I. Morphological analysis
Authors: Sobel J. Sabina , Szczesny Thaddeus M. 
Published: May 2005

AbstractDifferentiation in the mouse embryo begins at the 8‐cell stage when the blastomeres spread against each other in a process called compaction. The spreading behavior of blastomeres on lectin‐coated coverslips mimics that of blastomeres in the embryo, and we have utilized this model system to obtain an en face view of the membrane skeleton in the spreading blastomeres. Embryos were cultured on the coverslips for periods ranging from 20 sec to 6 hr, and the cells were disrupted to expose the cytoplasmic face of the adherent membranes and their associated filaments. The “membrane lawn” preparations were fixed, critical point dried, rotary shadowed, and the replicas examined by transmission electron microscopy.Using this technique we found that the plasmalemma of rounded blastomeres is associated with a lacy 3‐dimensional filamentous meshwork that is transformed into a thin mat of densely woven filaments when the cells flatten. The overall organization of the membrane skeleton is similar in flattening 2‐ and 8‐cell embryos, but there are significant differences in the time required for spreading to take place, in the means whereby the membrane skeletons are reorganized, and in the extent of maximal flattening. The significance of these observations for the compaction process is discussed.
Talpid2 mutant chick limb has anteroposterior polarity and altered patterns of programmed cell death
Authors: Dvorak Leah , Fallon John F. 
Published: May 2005

AbstractThe talpid2(ta2) chick mutant is of interest for the study of limb pattern formation. Talpid2 is a simple Mendelian recessive lethal mutation which affects the mesoderm and results in short, spade‐like, polydactylous wings and legs. Here, we describe ta2 limb development with particular attention to those aspects of ta2 which may illuminate the process of normal limb development. From the onset of budding, ta2 limb buds are significantly wider than normal buds along the anteroposterior axis. They lack the normal anterior and posterior necrotic zones and have variable development of the central opaque patch. Interdigital programmed cell death is variable and may result in development of distal phalanges without more proximal ones. Talpid2 wing vasculature is similar to that of normal wings, but ta2 legs are supplied by four large blood vessels. Feathers form regular, parallel rows, similar to normal feathers, but ta2 embryos lack the loose mesenchyme which separates the feather buds. Finally, and most significantly, ta2 wings and legs display anteroposterior polarity. Anterior and posterior limb skeletal elements can be clearly distinguished from one another within the ta2 phenotype. Our observations suggest that the ta2 mutant may be useful in analyzing programmed embryonic cell death and anteroposterior limb pattern formation.
Differentiation of the anterior body wall and truncal epidermis and associated co‐migration of cutaneous nerves and mesenchyme
Authors: Munger G. Torrey , Munger Bryce L. 
Published: May 2005

AbstractThe present study examines the relationship between the migration of mesenchyme and associated cutaneous nerves that are involved in the closure of the anterior body wall in embryonic mice and rats by light and electron microscopy. The sternum is formed by the migration of condensations of mesenchyme originating in the dorsolateral body wall known as sternal bands. In the course of analyzing this process in rodent embryos we have identified similar paired caudal extensions of the sternal bands that are responsible for the closure of the abdominal wall following resolution of the umbilical hernia, and we suggest these bands of mesoderm should be referred to as the abdominal bands. Both the sternal and abdominal bands are associated with the development of the segmental spinal nerves and their cutaneous terminal branches. The first cutaneous nerve to reach the skin surface in rats is the later cutaneous nerve (LCN) at E13.0 days followed by the posterior and anterior cutaneous nerves (PCN and ACN) at E13.5 days. The ACN co‐migrates with the sternal and abdominal bands, and terminal branches of axons from the ACN approach the epidermis during this migration. Differentiation of the epidermis could be recognized as a change in shape of epidermal cells from squamous to cuboidal, and this initial differentiation coincides with the onset of cutaneous innervation, beginning at the site of the LCN and following the extent of innervation of the PCN as well as the migration of the mesodermal bands and associated ACN. The paired ACN's meet in the ventral midline at E16.5 in rats as the sternal bands fuse, and terminal axons from both nerves densely innervate the midline skin. The wave of cutaneous differentiation in the trunk is associated with the onset of cutaneous innervation, and this process is associated with the co‐migration of bands of mesoderm that close the anterior body wall.
The use of the optical disector to estimate the total number of neurons in the developing chick lateral motor column: Effects of purified growth factors
Authors: Nurcombe Victor , Wreford Nigel G. , Bertram John F. 
Published: May 2005

AbstractCompetition between neurons for limited amounts of trophic factors is believed to be the basis for large‐scale neuronal death during the normal development of the vertebrate nervous system. In this study, an unbiased stereological counting method, an optical disector/Cavalieri combination, was used to estimate the total number of motor neurons in the lateral motor column of the developing chick and to assess the effects of four growth factors on neuronal numbers. The total number of neurons in lateral motor columns at embryonic day 6 (E6), E8, E10 and E12 were 18,747 ± 1,369 (mean ± SD), 15,037 ± 1,816, 10,245 ± 940, and 8,802 ± 797, respectively. Daily exposure from E6 to E9 to three of the growth factors (basic fibroblast growth factor, bFGF; leukemia inhibitory factor, LIF; nerve growth factor, NGF) had no effect on total neuron number at E10. However, exposure to ciliary neurotrophic factor (CNTF) from E6 to E9 significantly increased (P < 0.05) the number of neurons in the lateral motor column (13,610 ± 725, compared with 10,058 ± 204 in normal saline controls). These results are in agreement with previous reports of large scale neuronal death in the developing chick lumbar lateral motor column between E6 and E12 and confirm that exposure to growth factors such as CNTF can mitigate the course of normal ontogenetic cell death. The optical disector/Cavalieri combination is an efficient method for counting neurons: on average, following sectioning and staining, less than 30 min was required to estimate the total number of motor neurons in a lateral motor column with a coefficient of error of approximately 10%.
Widespread release of peptides in the central nervous system: Quantitation of tannic acid‐captured exocytoses
Authors: Morris John F. , Pow David V. 
Published: May 2005

AbstractTannic acid methods have been applied to capture the exocytosis of peptide‐containing granules from peptidergic neurons. The captured exocytoses have been quantitated to assess the proportion and amount of peptide released at different parts of the neuronal membrane. Examination of hypothalamic synaptic boutons shows that only about one‐half of the peptidergic vesicles is exocytosed into the synaptic cleft and also that exocytosis also occurs from undilated peptidergic axons. Study of the magnocellular neurosecretory system reveals that all parts of their extensive terminal arborization appear to be equally capable to exocytose peptide. Only about one‐half of their peptide is released from their nerve endings, which abut the capillaries. The remainder is released much deeper in the lobules of secretory tissue where its principal target(s) could be the pituicytes and/or neurosecretory axons. Dendrites of magnocellular neurons are also capable of releasing peptide by exocytosis and dendrites could release sufficient oxytocin and vasopressin to account for the peptide known to be released into the hypothalamus.We conclude that peptidergic neurons release substantial amounts of peptides from all of their processes and that this must be taken into account when considering what functions those peptides might serve.
Gonadotropin‐releasing hormone mRNA in the rat: Distribution and neuronal content over the estrous cycle and after castration of males
Authors: Malik Karl F. , Silverman Ann‐Judith , Morrell Joan I. 
Published: May 2005

AbstractThe decapeptide gonadotropin‐releasing hormone (GnRH) stimulates release of luteinizing hormone (LH) and follicle‐stimulating hormone (FSH) from the anterior pituitary. In the present study we used a 51‐base oligonucleotide probe and in situ hybridization to study the neuronal content of GnRH mRNA at several time points in the estrous cycle and 7 days after castration of male rats. GnRH mRNA containing cells were found in the medial septum (SEPT), the vertical and horizontal limbs of the diagonal band of Broca (DBB), and throughout the preoptic area (POA) from the organum vasculosum of the lamina terminalis (OVLT) to its caudal merger with the anterior hypothalamus.The number of neurons producing detectable quantities of GnRH mRNA was not different either among females killed at 0700 h proestrus, 1000 h estrus, or 1900 h of diestrus 1 or between intact male rats and male rats killed 1 week after castration. We did, however, detect a significant difference in the number of GnRH mRNA producing neurons between males and females (P < 0.05), where females had 20% more labeled cells.We detected no significant difference in the relative copy number of GnRH mRNA molecules (grains per labeled cell) either over the estrous cycle or between intact and castrate males. However, females overall had 24% more grains per labeled cell than males (P < 0.05). These results suggest that gonadal steroid regulation of GnRH both over the estrous cycle and after short‐term castration of males is mediated primarily by cellular processes subsequent to GnRH gene regulation. Furthermore, these results suggest that biosynthetic activity of GnRH is higher in females than in males.