Distribution of 3H-fucose in the transseptal ligament of the mouse.
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Animals↗
Biomedical subjects
R B Johnson
Publications and source records attributed to R B Johnson.
Effects of orthodontic tooth movement on the Alcian blue staining patterns of rat alveolar bone: an histochemical study.
There is little information available concerning the effects of orthodontic forces on glycosaminoglycans (GAG) of alveolar bone. The present study identifies changes in Alcian blue staining intensity in rat alveolar bone undergoing resorption resulting from a heavy (25g) tipping force applied to the adjacent teeth by a separating spring. One day after force application, bone from treated animals (internal control and experimental sides) demonstrated more intense staining with Alcian blue, pH 1.0 (p less than 0.005) and pH 2.5 (p less than 0.05) than external controls (untreated animals). By day 3, the intensity of Alcian blue staining of treated alveolar bone was similar to untreated. Chondroitinase AC, ABC and testicular hyaluronidase predigestion did not completely block the staining reaction, suggesting that both GAG and noncollagenous proteins were demonstrated. Mean cross-sectional areas of the interdental septum of the experimental side were nearly 44% less than that of the internal control side after 3 days and nearly 62% less after 5 days. The study suggested that alterations in bone GAG levels occurred prior to tooth movement as histochemical changes occurred after force application but before initiation of significant septal resorption. A precise appraisal of the types of macromolecules effected awaits future biochemical analysis. The results of the present work strongly suggest the use of an external control group for future studies, as Alcian blue staining reactions of the internal control side of treated animals were not similar to those of external controls.
Alcian Blue↗
Proteoglycans of alveolar bone of diabetic and non-diabetic mice: a histochemical study.
The effect of diabetes mellitus on the interdental alveolar bone has been long debated. The present study reported the distribution of glycosaminoglycans (GAG) in normal and diabetic alveolar bone using histochemical techniques. Animals were rendered diabetic and killed at 2, 4, 6 and 9 weeks after injections. Tissues were stained with Alcian blue 8GX dye (pH 2.5) to demonstrate GAG and the intensity of the staining reactions compared with age-matched controls. During the experiment, weights of control animals did not change significantly; weights of diabetic animals were significantly less than initial weights from 0-6 weeks (p less than 0.001), but became nearly equal by 9 weeks. Staining intensity of diabetic bone demonstrated initial decrease (0-4 weeks) followed by a marked increase (4-9 weeks) suggesting an early decline in bone GAG levels followed by increased bone GAG levels as compared to age-matched control and initial levels. Bone GAG levels were significantly different between diabetics and age-matched controls at 2 (p less than 0.005) 4 (p less than 0.001), 6 (p less than 0.001) and 9 (p less than 0.001) weeks after streptozotocin injections. Digestion with chondroitinase AC, ABC and streptomyces hyaluronidase suggested significant differences between control and diabetic bone matrix in the levels of chondroitin 4 and 6 sulfates (p less than 0.05) and hyaluronic acid (p less than 0.001) but not dermatan sulfate. In control and diabetic bone, chondroitin sulfates were located within the bone matrix, dermatan sulfate within bone matrix and Sharpey fiber bundles.(ABSTRACT TRUNCATED AT 250 WORDS)
Alveolar Process↗
A classification of Sharpey's fibers within the alveolar bone of the mouse: a high-voltage electron microscope study.
In the remodeling interdental septum of the mouse, four types of Sharpey's fibers were observed. Classification of these fiber types was based on characteristics of their termination within the septum in relation to the resorption-related reversal line separating old and new bone. "Severed fibers" were located only within old bone and terminated at the reversal line. "Arborized fibers" were located only within new bone and terminated therein. "Adhesive fibers" were located within new bone and terminated within a heavy band of granular material at the reversal line. "Continuous fibers" had components within old and new bone. These components were connected across the reversal line by nonstriated fibrils. Adhesive fibers were the least numerous type; severed and arborized fibers were observed at nearly equal frequency. Continuous fibers were the most numerous type, their numbers being significantly greater than any of the other types (P less than .001). Mean numbers of continuous fibers were greater than the mean total of the three other fiber types (P less than .001). Mean numbers of severed, adhesive, and arborized fibers were not statistically different. The study suggested that continuous fibers could be transalveolar--that is, ones which pass through the septum without interruption joining fibers of the adjacent periodontal ligament. Maintenance of their spatial continuity appeared to require a connecting protein to orient new unit collagen fibrils to old ones in areas of reversal. Thus, transalveolar fiber bundles could be characterized as being composed of old and new segments joined by a connecting protein. As their unit collagen fibrils did not cross resorption-related reversal lines these fibers were spatially continuous but temporally discontinuous.
Alcian Blue↗
Effects of orthodontic forces on the morphology and diameter of Sharpey fibers of the alveolar bone of the rat.
There is little information available concerning the effects of functional and therapeutic forces on Sharpey fibers and adjacent bone matrix. In the present study, springs were placed between the left first and second maxillary molar teeth of rats and retained for 1, 2, 3, 4, or 5 days. The right side served as a control. Tissues from sham-operated, untreated animals were also studied. Maxillae were removed, fractured, rendered anorganic with sodium hypochlorite, and then examined by scanning electron microscopy (SEM). Some tissues were demineralized and examined by high-voltage electron microscopy (HVEM). Sharpey fibers were studied at the alveolar wall and at the midline of the interdental septum (intra-septal Sharpey fibers). In 5-day experimental tissues, SEM showed intra-septal Sharpey fibers had either a reduced number of, or lacked, unmineralized cores. Unit collagen fibrils in 5-day tissues viewed by HVEM were densely packed into Sharpey fibers which had no afibrillar areas. Sharpey fibers at the alveolar wall demonstrated no observable changes in morphology or in pattern of mineralization. After 5 days of spring placement, the mean diameters of intra-septal fibers were significantly less than those at the alveolar wall (p less than 0.001). The disparity in Sharpey fiber diameters of treated and untreated control animals suggests that untreated controls are essential to the design of studies of rodent tooth movement. This study suggests that orthodontic tooth movement produces changes in the morphology and mineralization patterns of Sharpey fibers which might affect the mechanical strength of the periodontium.
Alveolar Process↗
Isolated cardiac aspergillosis after bone marrow transplantation.
A 15-year-old girl developed isolated cardiac aspergillosis after allogeneic bone marrow transplantation. Predisposing factors included severe graft-vs-host disease with gastrointestinal tract involvement and immunosuppressive therapy including cyclosporine. The patient died of cardiopulmonary failure 11 weeks after transplantation.
Adolescent↗
Variation of serum and intestinal gluten antibody specificities in coeliac disease.
Protein blotting techniques were used to investigate the gluten specificity of IgA and IgG antibodies in sera and intestinal aspirates from patients with coeliac disease and normal controls. Initially, discontinuous SDS polyacrylamide gel electrophoresis was used to separate the flour proteins. All normal and coeliac sera contained antibodies which bound to various of the gliadin proteins. In only a few sera was binding found to the high molecular weight glutenin subunits, while none was detected to the salt-soluble wheat proteins. Polyacrylamide gradient gel electrophoresis was then used to further separate the gliadin proteins. Almost all normal sera examined showed similar gliadin specificity, binding uniformly to all gliadin groups. While approximately a quarter of the coeliac sera showed even binding to all of the gliadin proteins, the majority showed antibody binding intensely to discrete groups of gliadin bands. We were unable to identify any gliadin band(s) which only bound antibodies from coeliac patients in comparison with normal subjects. The specificities of IgG and IgA serum antibodies were identical for each patient examined, but some differences between serum and intestinal IgA specificities were found for certain patients.
Adult↗
Human disease and the evolution of pathogen virulence.
Theorists who make a priori generalizations about the tendency of host-parasite systems to co-evolve toward commensalism or increased parasitism err because they do not consider the empirical relation between host pathology and pathogen transmission. Natural selection should favor increased pathogen virulence in diseases where host pathology contributes to pathogen transmission and favor decreased virulence when pathology impedes transmission. This paper classifies important human diseases according to the contribution human pathology makes to pathogen transmission.
Animals↗
The distribution of 3H-proline in alveolar bone of the mouse as seen by radioautography.
Previous studies of the turnover of alveolar bone collagenous proteins have devoted little attention to the variable patterns in this process caused by bone remodeling. The present study seeks to document changes resulting from physiologic tooth movements in the incorporation and removal of the 3H-proline label within the interdental septum of alveolar bone. One week following 3H-proline injection, three zones could be distinguished: the appositional band, new bone, and old bone. Radioautography demonstrated that formation of new bone on the distal wall of the septum entrapped fibers of the periodontal ligament to create Sharpey's fibers. At the alveolar crest, new bone entrapped transseptal fibers to form transalveolar Sharpey's fibers. Grain counts were made within each area and over the total septum and were compared statistically. The data strongly suggested regional variations in protein remodeling. Counts from old and new bone were significantly different from the total septum or the appositional band (P less than .001). Regression lines were drawn to represent incorporation and removal of the isotope; slopes were calculated and compared statistically. The rate of incorporation and removal was significantly greater in the appositional band and in the total septum in comparison to old bone (P less than .001). The rates of incorporation and removal in the appositional band, old bone, and total septum were significantly different (P less than .001). Half-life of the labeled protein of old bone was 16.78 weeks; in the appositional band, 7.66 weeks; and in the total septum, 7.64 weeks. These data suggest that regional variations in collagen remodeling must be considered in a study of interdental bone and that the total septal grain counts are not indicative of the remodeling in the component zones.
Alveolar Process↗
Ethical dilemmas in public health.
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Ethics, Medical↗
Comparative effects of local anesthetic preparations on gingival fibroblasts of the rat.
Cultures of rat gingival fibroblasts were exposed to various dilutions of lidocaine hydrochloride (Xylocaine), mepivacaine hydrochloride (Carbocaine), and prilocaine hydrochloride (Citanest). All three anesthetics produced cell-rounding and detachment from the substrate, which varied depending on the anesthetic, its concentration in the medium, and the duration of exposure (p less than 0.001). Effects were not pH-dependent in the range of 7.0-7.4 and were not modified by epinephrine in the concentration normally present in commercially prepared anesthetic solutions. Prilocaine produced morphological changes at a greater rate and at a lower concentration than did lidocaine or mepivacaine (p less than 0.001). The effects elicited by prilocaine were irreversible, since prolonged exposures to it resulted in various toxic effects: (1) detachment of the cells from the substrate, and (2) development of pyknotic nuclei and circumferential halos in cells that remained attached. The study strongly suggested that prilocaine has the potential to be more toxic to fibroblasts than either mepivacaine or lidocaine, a situation of potential clinical importance.
Anesthetics, Local↗
Intestinal and serum antibody in coeliac disease: a comparison using ELISA.
Intestinal and serum antibody to antigens derived from gluten and other food proteins in 16 children with coeliac disease and 15 control subjects was measured using an enzyme-linked immunosorbent assay (ELISA). High concentrations of antibody to gluten antigens were found in children with coeliac disease who were on a diet which contained gluten. This antibody was predominantly in the IgA and IgM classes in intestinal fluid, and in the IgG and IgA classes in serum. When coeliac children transferred to a gluten-free diet for 6 months or more, anti-gluten antibody fell much more rapidly in serum than in intestinal fluid. Although no single measure of antibody, in any immunoglobulin class, to a gluten-derived antigen proved sufficiently discriminating to be suggested as a diagnostic test for coeliac disease, serum antibody, particularly in the IgA class, may be of value in following the progress of patients and in assessing their adherence to a gluten-free diet.
Adolescent↗
Potential hazard of mass praziquantel use.
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Cysticercosis↗
Ultrasonic microdissection of the mouse mandible: exposure of the vasculature of alveolar bone and myelinated axons of the pulp.
The present scanning electron microscopic study describes a new method for the exposure of blood vessels of mouse alveolar bone and myelinated nerves of the dental pulp. This technique differs from others because it does not remove the periodontal ligament, allowing study of the vascular continuity between alveolar bone and periodontal ligament. Fixed and demineralized mandibles are digested with bacterial collagenase (1 mg/ml) at 37 degrees C for 12 hours, exposed to buffered osmium tetroxide for 24 hours, and ultrasonicated at 80 kHz for 5 minutes. The technique demonstrates that the vascular distribution of the interdental and interradicular septa is different. Vessels pass horizontally through the interdental septum and are continuous with vessels of the adjacent periodontal ligament. Vessels of the interradicular septum branch from a central vessel, pass toward the adjacent periodontal ligament, and become continuous with its vessels. Thus, the pattern of vessel distribution of the interdental septum of the mouse has little similarity to that of man or of research animals. The present study provides an improved method for demonstration of bone vasculature and pulpal axons while retaining valuable anatomical landmarks.
Alveolar Process↗
The effect of diet on systemic immune responses to wheat gliadin.
These studies examined the influence of gluten ingestion on the murine immune response to this cereal antigen. The results demonstrated that the level of specific antibody in the serum of mice immunised with gliadin is markedly reduced when gluten is present in the diet on which the animals were raised. Serum antibody concentrations in the gluten-free (G-F) mice were between 10- and 50-fold greater than those in the standard (STD) mice. The suppression of the antibody response to gliadin in the gluten-fed mice appeared to be antigen-specific, as STD mice responded normally to unrelated antigens such as sheep red blood cells (SRBC). This hyporesponsiveness towards gliadin develops very early in the animals' life. We suggest that this may occur through the transfer of small immunogenic fragments from mothers to their offspring either in utero or post-natally in the milk.
Animals↗
Effects of experimental diabetes mellitus on alveolar bone loss in periodontal disease-susceptible mice.
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Alveolar Process↗