1,721,033 research outputs found
Acute tubulo-interstitial nephritis requiring dialysis associated with intermittent rifampicin use : case report
No full textRifampicin is one of the most effective antibiotics used for the treatment of tuberculosis and severe staphylococcal infections. Intermittent administration of high doses of rifampicin has been associated with frequent adverse reactions, including hepatotoxicity and nephrotoxicity, sometimes resulting in acute renal failure. We describe a case of rifampicin-associated acute renal failure, with biopsy findings of tubulointerstitial nephritis; inflammatory cells were characterized by immunohistochemistry, which showed immunoreactivity for CD3 and CD5 (T lymphocytes) and for CD68 (macrophages). The patient presented with a very rapid systemic reaction to the offending drug and rapid deterioration of renal function, which required dialysis treatment. The response to rifampicin discontinuation was excellent: no further therapy was required, as renal function began to improve within several days and returned to normal values (serum creatinine 1.17 mg/dl) seven months after the onset of symptoms. When prescribing rifampicin the physician should investigate previous use of the drug, because re-exposure is a critical factor in predicting the possibility of drug-induced acute renal failure
Scanning electron microscopy of collagen fiber orientation in the bone lamellar system in non-decalcified human samples.
No full textPrevious studies on collagen fiber orientation have led to different interpretations and theories about the fiber arrangement in the lamellar compact bone. The purpose of this investigation was to provide new and more in-depth data on fiber arrangement in the lamellar bone system in order to explain the orientation of the fiber bundles. This was carried out by applying a simple method of preparation which permitted observation of non-decalcified samples. A previously isolated Haversian system was subjected to slow bending up to reaching the fracture point. Hence, the fracture surface was observed by SEM. The same samples were also observed by polarized light microscopy. A significant alternation of fiber orientation in the adjacent lamellae was observed. Different domains of differently oriented fibers were present within the same lamella; conjugating fibers connecting adjacent lamellae were also shown. This method avoided most of the artifacts due to chemical treatment of bone samples. The results can be easily interpreted by means of the same criteria applied in mechanics for the studying of composite materials
Ultrastructural localization of advanced glycation end products and beta2-microglobulin in dialysis amyloidosis
No full textBACKGROUND: beta2-microglobulin (beta2m) is considered to be the amyloidogenic precursor in dialysis-related amyloidosis (DRA, Abeta2M amyloidosis). beta2m modified with advanced glycation end products (AGE) may be an important factor in
the pathogenesis of DRA. The presence of AGE in beta2m-positive amyloid deposits and surrounding macrophages has been demonstrated by immunohistochemical techniques in light microscopy.
METHODS: In order to better define the localization of beta2m and AGE in amyloid deposits and in cells, carpal tunnel connective tissues obtained from surgical specimens in six patients with DRA were studied by mmunohistochemistry and electron microscopy, using the avidine-biotine complex and immunogold staining procedures, respectively. A polyclonal rabbit anti-human beta2m and two monoclonal mouse anti-AGE antibodies [AG-1 anti-imidazolone and AG-10 anti-N(epsilon)-carboxymethyl-lysine] enabled us to label their respective antigens at the optical and ultrastructural level.
RESULTS: with both techniques, extracellular amyloid deposits strongly reacted with anti-beta2m and anti-AGE antibodies, although the immunoreactivity of beta2m
was more intense. Macrophage-like synovial cells (CD-68 positive) surrounding amyloid deposits were also immunoreactive for beta2m and AGE, which were detected
in lysosomes and in intracellular fibrillar material. Anti-AGE reactivity was also evident in collagenous structures in the absence of beta2m or amyloid deposits, supporting the proposal that AGE modification of collagen might have pathogenic relevance in the development of DRA.
CONCLUSIONS: The co-localization of AGE and beta2m, both intra- and
extra-cellularly, in amyloid fibrils was confirmed by immunoelectron microscopy;
however, the positivity of collagen to anti-AGE antibodies and a different
pattern of intracellular localization suggest that molecules other than beta2m
may also be modified by AGE and may be involved in the pathogenesis of DRA
Early skin changes of progressive symmetric erythrokeratoderma
No full textProgressive symmetric erythrokeratoderma or Gottron syndrome is a rare genetic disorder characterized by the presence of striking symmetric erythematous-keratotic lesions involving the upper and the lower limbs. The first presenting clinical signs have been rarely reported in the literature. In our report we describe these starting lesions of Gottron syndrome and we show their clinical evolution
Effects of broad frequency band electromagnetic fields on HSP70 expression and ischemia-reperfusion in isolated rat hearts
No full text
A morphological study on femoral heads in human hip joint osteoarthrosis.
No full textSeveral pathogenetical and clinical interpretation of osteoarthritic modifications are given in the literature. In this work we tried to compare in humans macroscopic, structural and ultrastructural observations on eight osteoarthritic with four femural heads from control patients. The sample for Light Microscopy and Scanning Electron Microscopy observations came from selected regions of the femural head, which included both cartilage and bone tissue of loaded and unloaded regions. The cartilage showed superficial lesions, such as erosions and fissures, and deep lesions that included matrix alterations and chondrocyte proliferation. In relation to the thickening of the subchondral bone we noticed an irregular bone-cartilage surface with signs of bone tissue proliferation. The trabeculae appeared thickened in loaded zones and rarefied in unloaded ones. Cavities were sometimes present at different depths in cancellous bone. Our observations allow us to conclude that cartilage lesions are precocious, diffusely located and relatively independent of the considered zone of the femural head, while bone tissue alterations seem evenly sited and chronologically subsequent. The cavities in the cancellous bone could produce load modifications and consequent bone deformity
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
