The most relevant defects in glasses are categorized and investigated by appropriate microanalytical techniques. Since these defects very often present a real challenge because of complex chemical and mineralogical properties, a multimethod approach is necessary to supplement or confirm the findings from scanning techniques. The combination of electron probe microanalysis/energy-dispersive x-ray (EPMA/EDX) and laser ablation inductively coupled plasma mass spectroscopy (LA-ICP-MS) allows the determination of element trace concentrations in a knot, a glassy defect, thus finally enabling the identification of a special source of the defect from otherwise nondistinguishable refractories. The type of crystals can be determined exactly by the use of EPMA and x-ray dispersion (XRD), stones (a crystalline agglomerate) are analyzed by EPMA/EDX pointing to a possible source for this defect; results on metallic inclusions, "filled bubbles," and surface defects are reported and defect sources are discussed. Since close cooperation with the production departments and knowledge of production techniques and conditions are necessary for the diagnosis to take appropriate countermeasures, an approach is presented which systematically accumulates all information into a data base. The structure of such "expert systems" is described, which leads to correlation of appearance, analytical data, and source of the defects for even more accurate diagnosis and faster reaction.

Journal Article↗

PubMedDate not supplied

Age-related variation in the DNA-repair synthesis after UV-C irradiation in unstimulated lymphocytes of healthy blood donors.

UV-C light-induced DNA-repair synthesis was studied in unstimulated lymphocytes of 51 healthy blood donors aged between 17 and 74 years. Repair synthesis was measured by the incorporation of [3H]thymidine after a 2-h incubation period in the presence of 2 mM hydroxyurea. The evaluation included (1) the spontaneous DNA-synthesis in unirradiated lymphocytes with and without hydroxyurea, (2) the DNA-repair synthesis in lymphocytes irradiated with UV-light. The interindividual variation was significantly higher than the methodological variation ascertained in 24 persons in whom 2 determinations were carried out. In blood donors aged between 17 and 39 years, the spontaneous DNA synthesis, both with and without hydroxyurea, was significantly lower than in older individuals. The DNA-repair synthesis was dependent on the dose of UV-C light between 2 and 16 J/m2. There were no significant differences in DNA-repair synthesis in the age range 17-74 years. The variations in rate of DNA-repair synthesis (greater or lesser degree of [3H]thymidine incorporation beyond the 99% confidence range) were wider in older (44-74 years), than in younger individuals.

Adolescent↗

PubMedDate not supplied

Task-specific authoring functions for end-users in a hospital information system.

Authoring functions--integrated in a Hospital Information System (HIS)--provide a means for physicians and nurses to adapt partly their man/machine interface. We successfully implemented task-specific authoring functions that enable end-users to comprehend and structure a large body of multimedia documents, to focus attention during medical decision making, to speed up medical tasks and to standardise the drafting of documents.

Decision Making, Computer-Assisted↗

PubMedDate not supplied

In situ immunophenotyping of lymphocytes/macrophages: grading of lymphadenopathy, staging and pathophysiology of HIV infection.

Histological changes in lymph nodes in HIV1-related lymphadenopathy were analysed in 106 lymph node biopsies and in lymph nodes of 140 autopsy cases. A classification system of five stages was established on the basis of histological and immunohistochemical studies. The analysis confirmed a close correlation between the progression of HIV1-related disease and our staging system. Although the classification is chiefly based on histological and immunohistochemical changes of the follicles, other frequently seen findings are included. Alterations in the interfollicular tissue, e.g. vascular proliferation and lymphocyte depletion, correspond to an increasing concentration of macrophages within this tissue. In HIV1 infection, the macrophages appear to produce high concentrations of angiogenic factors responsible for the frequent and sometimes extreme lymph node vascularization. Since the vascular proliferation can be subject to regression and sclerosis as seen in autopsy cases, the macrophages may lose the ability to produce large amounts of angiogenic factors in the final stage of the disease.

AIDS-Related Complex↗

PubMedDate not supplied

Pathophysiological mechanisms of HIV-induced defects in haematopoiesis: pathology of the bone marrow.

Bone marrow biopsies of 96 HIV1-infected patients were analysed histologically and by immuno- and enzyme histochemical techniques. Independently of the stage of disease, the bone marrow frequently exhibits hypercellularity and features of dysplastic haemopoiesis combined with mesenchymal alterations. In situ immunohistochemical analysis shows that there is a marked reduction in expression of the proliferation-associated nuclear antigen recognized by the Ki67 antibody. Comparison with non-infected controls reveals that there is a reduction in CD34+/myeloperoxidase-/naphthol AS-D chloroacetate- progenitor cells and an overproportional decrease in CD8+ lymphocytes in the bone marrow. Double staining revealed the presence of gag-coded HIV1 proteins in the above-mentioned CD34+ progenitor cells, in myelopoiesis cells, megakaryocytes and above all, in CD68+/acid phosphatase+ and alkaline phosphatase+ bone marrow reticular cells. From the latter results, it was concluded that HIV1-infected reticular cells may be disturbed in their ability to produce factors responsible for the short-range regulation of haemopoietic activity.

Acquired Immunodeficiency Syndrome↗

PubMedDate not supplied

Growth patterns, inflammatory cells and prognosis in AIDS-associated Kaposi's sarcoma.

AIDS-associated cutaneous Kaposi's sarcomas (KS) in 35 patients were the subject of a histopathological and immunohistochemical study. Histologically, the tumours were classified as granulation-tissue-like (GR, n = 10), angioma-like (A, n = 11), angiosarcoma-like (AS, n = 9) and as spindle cell type (SP, n = 5). There was a distinct relationship between the main growth patterns of KS and the CD4+ peripheral blood lymphocyte (PBL) count. A decrease in numbers of CD4+ PBL was correlated with an increase in the frequency of AS and SP growth patterns. There were no correlations between growth pattern and concentrations of protein S100+, MT1+, CD45+ and MAK387+ tumour-associated inflammatory cells. When the GR type was grouped together with the A type, and the AS type with the SP type, statistically significant differences emerged for CD45+ and MT1+ tumour-associated cells, and for survival time, respectively. In all these instances, the GR/A group values were higher than those of the AS/SP group. Additionally, linear correlation analysis revealed an inverse relationship between the concentrations of CD4+ PBL and of protein S100+ tumour-associated inflammatory cells within the GR/A group. In contrast to what is observed with certain tumours of HIV-negative patients, this suggests that a high concentration of protein S100+ tumour-associated cells may indicate a worse prognosis in the GR/A group. The concentration of MAK387+ tumour-associated macrophages did not vary as a function of the growth patterns, even when they were grouped together as described above.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗

PubMedDate not supplied

Functional abnormalities of monocytes/macrophages in HIV1-infected patients as demonstrated by the skin window procedure.

Skin window (SW) tests were performed in ten HIV1-infected patients and in ten healthy volunteers. The chemotaxis of monocytes/macrophages is weakened in AIDS patients, since the number of monocytes/macrophages attracted by the SW stimulus decreases in HIV1-infected subjects during the observation time, whereas the number increases in control individuals. HLA-DR expression decreases faster in AIDS patients than in healthy volunteers. Giant cell formation occurs and disappears earlier in HIV1-infected patients than in healthy control individuals. The results suggest that, at least in part, the impairment of chemotaxis and other functional abnormalities of mononuclear phagocytes are caused by their accelerated aging in HIV1-infected patients.

Acquired Immunodeficiency Syndrome↗

PubMedDate not supplied

In situ immunophenotype of macrophages and lymphocytes in granuloma formation of tuberculous lymphadenitis in HIV-infected and immunocompetent patients.

The phenotype of inflammatory cells in lymph nodes from 16 patients with culture-proven tuberculous lymphadenitis were examined by histological and immunohistochemical techniques. Eight patients were suffering from a symptomatic HIV1 infection and 8 patients were immunocompetent individuals without positive HIV1 serology. In addition, the lymph nodes of 2 AIDS patients with Mycobacterium avium-intracellulare infection were examined using the same techniques. Characteristic granulomas with or without caseation were observed in the 8 immunocompetent and the 4 HIV1-infected patients with less marked lymphopenia of CD4+ peripheral blood lymphocytes (PBL). In lymph nodes from the other HIV1-infected patients with more severe depression of CD4+ PBL, no epithelioid cell formation was present; instead, foamy macrophages were found. The phenotype of the macrophages underwent progressive changes in parallel with the decreasing numbers of CD4+ PBL. Foamy macrophages in M. avium-intracellulare infection exhibited remarkable erythrophagocytotic activity and may represent an end-stage phenotype. They were positive for S100 protein and did not produce lysozyme or alpha-1-antichymotrypsin. They lost the antigen which was detected by monoclonal antibody Mac387 whereas positivity for HLA-DR, CD68 and KI-M8 was preserved. While many lymphocytes expressed CD25 (IL2 receptor) in cases with typical granulomas, there was no such CD25 expression in cases without epithelioid cell formation. Although granulomas have been produced in experimental animals independently of cell-mediated immune mechanisms, our results suggest that T-cell functions are necessary for epithelioid granuloma formation in human tuberculosis.

Adult↗