Biomedical subjects
R Guggenheim
Publications and source records attributed to R Guggenheim.
Non-surgical periodontal treatment: where are the limits? An SEM study.
In the present scanning electron microscopic study, the possibilities and limitations of non-surgical root planing were investigated. 10 single-rooted teeth from 4 patients with advanced periodontitis were studied. The root surfaces were cleaned and planed without flap reflection, using fine curettes. The teeth were then extracted and the root surfaces were systematically examined by scanning electron microscopy (SEM) for the presence of residual bacteria and calculus. 29 of 40 curetted root surfaces were free of residues, if they were reached by the curette. On the remaining 11 surfaces, only small amounts of plaque and minute islands of calculus were detected, primarily at the line angles and also in grooves and depressions in the root surfaces. Instrumentation to the base of the pocket was not achieved completely on 75% of the treated root surfaces, however. The primary reason for this was the extremely tortous pocket morphology on the teeth selected for study. In conclusion, it may be stated that during non-surgical root planing in cases of advanced periodontitis, surfaces that can be reached by curettes are usually free of plaque and calculus. However, in many cases the base of the pocket will not be reached. It is for this reason that deep periodontal pockets should be treated with direct vision, i.e., after the reflection of conservative flaps.
[Studies on pigmented surface wrinkling retinopathy by scanning electron microscopy (author's transl)].
The light- and scanning electron microscopic appearance of 3 areas of pigmented epiretinal fibroplasia (pucker) are described in an eye removed following detachment surgery. The centre of each area of pucker consists of a fibroglial sheet covered by retinal pigment epithelium. The surface morphology of these cells resembles typical or slightly degenerated epithelium. Extensive areas of these pigment epithelial sheets were pigmentfree. There was no evidence that the pigment epithelial sheets exerted either direct or indirect traction on the inner surface of the retina. The origin of these cells and their role in the formation of retinal wrinkling is discussed.
Cell communication and specific adhesion in the microorganism Dictyostelium.
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Hormonal influences on the dog prostate--a correlation study with light microscopy, transmission and scanning electron microscopy.
Dog prostates under defined hormonal influences were investigated by light microscopy (LM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The normal acinar cell apices exhibited well-developed, densely packed microvilli. TEM demonstrated numerous secretory granules, indicating a high secretory activity. Following castration, the acinar cells of the dog prostate showed rounded apices. Most of the microvilli disappeared and only knob-like protrusions were seen. Castrated dogs following administration of 3 alpha-androstandiol showed fewer microvilli than the controls; however, a well-developed undulating surface could be observed. Castrated dogs given 3 alpha-androstandiol and cyproterone acetate showed almost completely atrophic glandular cells. Prostates of dogs with spontaneous benign prostatic hyperplasia (BPH) were characterized by pleomorphism of cell shapes and surfaces. The different hormonal influences induced changes of the prostatic surface structures and secretory activity.
Comparative scanning and transmission electron microscopy of the prostatic gland in different species (mouse, rat, dog, man).
Man, dog, rat and mouse prostatic glandular cells were compared by light microscopy (LM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). In rodents and dogs, a merocrine secretion exists, and in these species the undulating surface represented a confluence of secretory granules. The prominent secretory blebs observed in dog and human benign prostatic hyperplasia (BPH) corresponded to apocrine secretions. Also variations in the amount of secretory activity were seen. Androgenic hormones were responsible for the differentiation of the prostatic epithelial cells during development. Therefore, an absence of microvilli as well as the appearance of ruffles, microplicae, and bare cells were seen in the prepuberal and castrated rat. In the elderly rat and in human BPH, a pleomorphism of the apical cell surface was evident.
[Studies on fibrous and fibro-glial surface wrinkling retinopathy by scanning electron microscopy (author's transl)].
The scanning electron microscope was used to examine 16 cases of epiretinal membrane formation and retinal puckers which occurred in a variety of primary retinal disorders. In this first section the authors describe three types of epiretinal membranes: (1) Fibrous acellular membranes with and without vitreous adhesions. Retinal puckering was caused by vitreous traction with collagen strands binding the residual folds. (2) Fibrous membranes containing isolated glial cells. (3) Fibrous membranes partly covered by sheets of glial cells. In all three forms the acellular fibrous component is believed to represent vitreous cortex remnants. The invariable presence of these fibrous membranes at sites of retinal pucker and their relationship to wrinkled internal limiting membrane suggests that contraction of these membranes is responsible for retinal puckering. Morphological evidence of glial membrane contraction and collagen production by glial cells was not found.
Long-term cultivation of plasma cell leukemia cells and autologous lymphoblasts (LCL) in vitro: a comparative study.
Two long-term cell lines were established in vitro from the peripheral blood of a patient with plasma cell leukemia: one line with plasma cell proliferation, the other with lymphoblastoid cell proliferation (LCL). The 9-month-old plasma cell line showed the typical morphology of plasmoblasts. The cells neither had B- nor T-lymphocyte characterisitics, were EBV negative, and showed aneuploidy with various marker chromosomes, including the 14 q+ marker. The cytogenetic findings indicate a monoclonal proliferation of the plasmacells. No tumor growth in thymusless nude mice could be induced upon intracranial inoculation with these cells. In contrast, the autologous LCL, cultured after addition of exogenous EBV, showed the characteristic markers of lymphoblastoid cells, with the typical morphology of pear- and handmirror-shaped lymphoblasts, growing in clumps. They had C3- and Fc-receptors, surface-Ig, E-rosette-negativity, a diploid karyotype, and EBV dependent macromolecule synthesis. They lymphoblastoid cells produced intracranial tumors in nude mice in 8 out of 8 attempts.
[Findings on retinal surface by scanning electron microscopy. II. Vitreous detachment (author's transl)].
The authors describe their findings by scanning electron microscopy of the surface of the retina following secondary and primary senile posterior vitreous detachment. These findings are correlated with those of transmission electron microscopy. Extended nets formed by vitreous fibrils can be found on the retinal surface. The fibrils form a continuous feltwork, which cannot be traced by biomicroscopy or dissection of enucleated globes. This feltwork desintegrates in places or over a wide area and the basal membrane of the Müller cells becomes exposed. Structural differences in consequence of the two examination techniques well as possible artifacts are shown.
[Findings on retinal surface by scanning electron microscopy. III. Epivascular glial clusters (author's transl)].
The findings by scanning and transmission electron microscopy of multiple glial excrescences from the retina into the cortical vitreous body are described. These formations are located in lines above superficial retinal vessels. The findings are compared with those from light microscopy of similar formations. The pathogenesis and the possible significance as retinovitreal attachments for rhegmatogenous defects of the retina and for posterior vitreous detachments are discussed.
Haemoglobin crystals in the midgut of the tick Ornithodorus moubata Murray.
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[Findings on retinal surface by scanning electron microscopy. I. Retinal holes (author's transl)].
The findings by scanning electron microscopy on three retinal holes are described. An outgrow of a glial membrane with microvilli from the holes to the retinal surface can be seen. This epiretinal cell membrane grows on a felt of collagen fibres of the vitreoretinal borderlayer. Rudiments of visual receptors project from the deep walls into the holes. The layer of the pigment epithelial cells beneath the holes is remarkable by the abundance of microvilli.
Changes in alveolar capillary configuration at different levels of lung inflation in the rat. An ultrastructural and morphometric study.
Changes in alveolar capillary configuration during positive pressure lung inflation were investigated by transmission and scanning electron microscopy as well as by morphometric methods. As the airway pressure was raised, an increasing number of alveoli expanded. However, in fully inflated or overinflated lungs, a few collapsed areas persisted. In such areas, the air-blood tissue barrier was folded into the capillary space, dividing it into intercommunicating chambers. In expanded alveoli, the capillaries appeared as a continuous space delimited at each side by a tissue leaflet. This space was crossed by tissue bridges consisting of the thick portion of air-blood barrier. In overinflated lungs, the capillary space was compressed between the alveoli and thus collapsed. Our findings suggest that the thin porne. The variations of the capillary configuration seem to be determined either by "passive" deformations or by compression of the alveolocapillary membrane, or as a result of contraction of interstitial cells which are located in the thick portion of the air-blood barrier and are attached to the basement membranes of two adjacent alveoli. The relationship between alveolar dynamics and capillary configuration is considered to be a basic factor in ventilation/perfusion auto-regulation.