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Light Microscopic Analysis (light + microscopic_analysis)
Selected AbstractsA Sarcocystid Misidentified as Hepatozoon didelphydis: Molecular Data from a Parasitic Infection in the Blood of the Southern Mouse Opossum (Thylamys elegans) from ChileTHE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 6 2008SANTIAGO MERINO ABSTRACT. The blood of 21 adult South American mouse opossums (Thylamys elegans) captured from April through August of 2005 in central Chile was examined for parasites. Light microscopic analysis of blood smears initially suggested that a highly pleomorphic Hepatozoon species typical of American opossums was infecting erythrocytes. Unexpectedly, amplification by PCR and sequencing of a DNA fragment of the small subunit rDNA combined with phylogenetic analyses indicated that the parasite is not a member of the suborder Adeleorina, which includes the Haemogregarina and Hepatozoon species, but that it is a clearly distinct member of the suborder Eimeriorina, which includes the cyst-forming family Sarcocystidae. Therefore, a reclassification of this unusual intraerythrocytic apicomplexan will require additional life cycle, microscopic, and molecular analyses. [source] Hydroxyethyl starch-induced itch: Relevance of light microscopic analysis of semi-thin sections and electron microscopyJOURNAL DER DEUTSCHEN DERMATOLOGISCHEN GESELLSCHAFT, Issue 3 2007Stefanie Kamann Summary Background: Hydroxyethyl starch (HES) is widely used as a plasma substitute for improving microcirculation. A major side effect of HES is severe pruritus caused by HES deposits in the skin. Since specific changes are difficult to see in paraffin sections, electron microscopy is the golden standard technique in the diagnosis of HES-induced skin disease. Our aim was to compare electron microscopic search for HES deposits with other techniques. Patients and Methods: During the last ten years, we biopsied 21 patients suspected of having HES-induced pruritus. We compared conventional microscopy with hematoxylin & eosin and toluidine blue-stained paraffin sections, toluidine blue-stained glycide ether-embedded, semithin sections and transmission electron microscopy. Results: In 9 patients specific HES deposits could be found by evaluating toluidine blue stained semithin sections by light microscopy alone. In 6 of these cases electron microscopy was also done and confirmed the findings. In contrast, no specific findings due to HES deposits could be detected by conventional histology. Conclusions: If specific HES deposits are found in toluidine blue-stained, glycide ether-embedded semithin sections, electron microscopy is not required. [source] Cutaneous marginal zone B-cell lymphoma in the setting of fluoxetine therapy: a hypothesis regarding pathogenesis based on in vitro suppression of T-cell-proliferative responseJOURNAL OF CUTANEOUS PATHOLOGY, Issue 7 2006Thomas S. Breza Jr Introduction:, Drugs may be an important cause of atypical lymphocytic infiltration. Oftentimes, these infiltrates are in the context of pseudolymphomata. We report a patient who developed lymphocytoma cutis temporally associated with initiation of fluoxetine therapy that later went on to develop cutaneous marginal zone B-cell lymphoma. The response of peripheral blood lymphocytes to fluoxetine and other drugs was examined in an attempt to ascertain the potential role for drugs in the propagation of these infiltrates. Materials and Methods:, Routine light microscopic analysis and phenotypic studies were performed on tissue obtained from a skin biopsy. Lymphocyte mitogenic studies were carried out using increasing concentrations of fluoxetine, bupropion, and two anticonvulsants. Results:, An initial biopsy was consistent with lymphocytoma cutis. The patient stopped fluoxetine associated with lesional regression. The lesions recurred despite being off fluoxetine; a repeat biopsy was compatible with marginal zone lymphoma. Lymphocyte proliferation assays revealed a suppressive effect on T-lymphocyte proliferation at physiologic concentrations. Other tested drugs did not have a similar suppressive effect. Conclusion:, Fluoxetine may be associated with pseudolymphomata and marginal zone lymphoma. The inhibitory effects on T-lymphocyte function and more specifically T-suppressor function may lead to excessive antigen-driven B-cell proliferation. [source] Embryonic development of the oligochaete Enchytraeus coronatus: An SEM and histological study of embryogenesis from one-cell stage to hatchingJOURNAL OF MORPHOLOGY, Issue 1 2004Annette Bergter Abstract We describe the embryonic development of the soil-living oligochaete Enchytraeus coronatus (Enchytraeidae, Oligochaeta, Annelida). Enchytraeus coronatus is a direct developer. It follows the typical spiral cleavage mode of development that is highly conserved among annelids and a large number of other lophotrochozoan taxa that are collectively named "Spiralia." Scanning electron microscopy (SEM) was combined with light microscopic analysis of wholemounted and sectioned embryos, differentially processed through histological stainings, to reconstruct and document cellular movements and organogenesis from early cleavage stages until hatching. With the help of these data we have established a scheme of morphologically defined stages in order to facilitate future studies on the molecular and histological level that will allow a detailed cross-species comparison among annelids and other phyla. J. Morphol. 261:26,42, 2004. © 2004 Wiley-Liss, Inc. [source] Regional Analysis of the Ependyma of the Third Ventricle of Rat by Light and Electron MicroscopyANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 1 2008T. C. Mathew Summary Ependymal lining of cerebral ventricles lies at the interface between the ventricular cavities and the brain parenchyma. Ependymal cells are involved in various functions within the brain and play a major role in the production of the chemical principals of the cerebrospinal fluid. Histological studies on the regional variation of the third ventricular ependyma and the subependyma of adult rats were carried out by light and electron microscopic methods. For light microscopic analysis, methacrylate sections were used. In addition to the routine haematoxylin and eosin (H and E) staining for histological studies, the sections were stained with toluidine blue, cresyl violet and periodic acid Schiff's reagent (PAS). A regional analysis of the ependyma of the third ventricle showed that in most regions the ependyma was monolayered. The sidewalls and floor of the ventral portion of the third ventricle showed a multilayered ependyma. For descriptive purposes at the light microscopic level, the ependymal cells were classified, based on the cell shape (flat, cuboidal or columnar), presence or absence of cilia and the number of cytoplasmic granules present in the cells. Studies of transmission electron microscope have shown that these granules represent the cell organelles of the ependyma. The subependyma also showed a regional morphological variation, and, in most instances, contained glial and neuronal elements. In regions of specific brain nuclei, neurons were the major cell type of the subependyma. PAS staining did not show any positive granules in the ependymal cytosol. Characteristic supraependymal elements were present at the ependymal surface of the third ventricle. [source] Bone Tissue Responses to Surface-Modified Zirconia Implants: A Histomorphometric and Removal Torque Study in the RabbitCLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 2005Lars Sennerby DDS ABSTRACT Background: Zirconia ceramics are biocompatible and have mechanical properties that make them suitable as materials for dental implants. Little is known about how surface modification influences the stability and bone tissue response to zirconia implants. Purpose: The objective of the investigation was to histologically and biomechanically evaluate the bone tissue response to zirconia implants with two different surface modifications in comparison with machined, nonmodified zirconia implants and oxidized titanium implants. Materials and Methods: Threaded zirconia implants with a diameter of 3.75 mm with either a machined surface (Zr-Ctr) or one of two surface modifications (Zr-A and Zr-B) were manufactured. Oxidized titanium (Ti-Ox) implants 3.75 mm in diameter were also used. The implants were characterized with regard to surface topography using an interferometer. Twelve rabbits received 96 implants using a rotational scheme, two in each tibia and two in each femur. The implants in six rabbits were subjected to removal torque (RTQ) tests after a healing period of 6 weeks. The implants in the remaining six animals were removed en bloc for light microscopic analysis. Back-scatter scanning electron microscopic (BS-SEM) analyses were used to evaluate the state of the bone-implant interface at the modified zirconia implants after RTQ testing. Results: The Ti-Ox and Zr-A implants showed the highest surface roughness, followed by the Zr-B implants and, finally, the Zr-Ctr implants. The nonmodified ZrO2 implants showed statistically significant lower RTQs than all other implants. No significant differences in bone-implant contact or bone area filling the threads were observed. BS-SEM showed intact surface layers of the surface-modified implants after RTQ testing and revealed fracture of the interface bone rather than a separation. Conclusion: The present study showed a strong bone tissue response to surface-modified zirconia implants after 6 weeks of healing in rabbit bone. The modified zirconia implants showed a resistance to torque forces similar to that of oxidized implants and a four- to fivefold increase compared with machined zirconia implants. The findings suggest that surface-modified zirconia implants can reach firm stability in bone. [source] | |||||||||||||