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  • 1
    ISSN: 1365-2559
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Aims : Bone marrow is the major site of B-cell generation in humans. While in early childhood a high number of B-cell precursors is found in the bone marrow, only very few such cells are usually detectable in adult bone marrow. To assess the number of immature B cells present after haematopoietic cell transplantation the number of terminal deoxynucleotidyl transferase (TdT)-positive cells in regenerating bone marrow of adult patients was analysed.Methods and results : Bone marrow biopsy specimens were analysed from patients after allogeneic bone marrow transplantation (BMT; n = 14) or stem cell transplantation (SCT; n = 25) and autologous BMT (n = 9). Specimens from 11 untransplanted adult patients and 11 infants were also studied, as negative and positive controls, respectively. Immunohistochemistry was performed on paraffin-embedded bone marrow biopsy sections using TdT as a marker of lymphoid progenitors. Immunoreactivity for CD79a, CD20 and CD10 was used to confirm their B-cell origin. Using computer-assisted automated image analysis we quantitatively assessed the TdT+ cells present. We found a significant increase in the numbers of B-cell precursors in the bone marrow after allogeneic and autologous BMT/SCT compared with adult controls (P = 0.022). To analyse this in detail, we followed some patients after allogeneic BMT/SCT for up to 1445 days, when a marked B-cell increase was still detectable. However, the median number of TdT+ B cells after BMT/SCT was significantly lower than the number of equivalent B cells in infantile bone marrow biopsy specimens (P 〈 0.001).Conclusions : Bone marrow of adult patients after BMT/SCT is capable of initiating vigorous precursor B-cell generation, which is not seen in untransplanted adults. However, the increase of immature B cells was variable in our study. Only in two young adult patients did it reach the magnitude of B-cell generation seen in infantile bone marrow where immunocompetent B cells are produced normally. A marked increase in number of immature B cells post-transplant may mimic B-cell acute lymphoblastic leukaemia (B-ALL). This is a potential problem in patients transplanted for B-ALL itself. Since reactive and neoplastic B-cell precursors share the same immunophenotype in paraffin-embedded tissue, additional tools, particularly molecular techniques, may have to be employed to establish the correct diagnosis.
    Materialart: Digitale Medien
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  • 2
    ISSN: 1365-2559
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: A multifocal lymphoepithelioma-like carcinoma and a low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT-type) were found simultaneously in the stomach of a 65-year-old patient. Carcinoma and lymphoma were intimately associated forming complexes resembling lymphoepithelial lesions at the primary gastric site and in lymph node metastases. The two tumours had developed on a background of severe chronic-atrophic gastritis of the mucosa of antrum and fundus. Autoantibodies to normal gastric glandular tissue could be demonstrated in the patient’s sera. Using non-radioactive in situ hybridization (ISH), Epstein-Barr virus (EBV) sequences were detected in virtually all carcinoma cells but neither in the non-neoplastic mucosa nor in the lymphoma. These findings suggest that a focal EBV infection occurred early in the development of the carcinoma followed by a subsequent clonal expansion of the EBV-containing tumour cells. A neoplastic transformation in MALT-type lymphoma is not EBV-related but might be triggered by altered immune mechanisms.
    Materialart: Digitale Medien
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  • 3
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    Histopathology 27 (1995), S. 0 
    ISSN: 1365-2559
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    Histopathology 26 (1995), S. 0 
    ISSN: 1365-2559
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: A histogenetic classification of thymic epithelial neoplasms proposed by Müller-Hermelink and co-workers has been shown by a number of recent studies to be of clinical and prognostic value. Reproducibility is an important criterion for the acceptance of any new classification for general diagnostic use. The reproducibility of this classification was tested on 51 cases of thymic epithelial neoplasia, by comparing results obtained by pathologists working from published criteria only with those results obtained by the pathologists who developed the classification. In 78% of cases there was complete concordance of results. Analysis of the 22% discordant cases showed that this discordance was due to a degree of subjectivity in determining cut-off points between categories adjacent to each other in the morphological spectrum of thymic epithelial neoplasia (medullary v. mixed, cortical v. well-differentiated thymic carcinoma). In terms of the important clinical distinction between benign (medullary and mixed) thymomas and those with more aggressive biological behaviour (cortical types and well-differentiated thymic carcinoma), the degree of reproducibility was 96%. The high degree of reproducibility of this histogenetic classification of thymic epithelial neoplasms should facilitate its acceptance and use in routine diagnostic pathology.
    Materialart: Digitale Medien
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  • 5
    Digitale Medien
    Digitale Medien
    Oxford, U.K. and Cambridge, USA : Blackwell Science Ltd
    Histopathology 33 (1998), S. 0 
    ISSN: 1365-2559
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Aims: De-differentiated chondrosarcoma is characterized by the presence of two distinct chondroid and nonchondroid tumour portions. The aim of our study was to investigate the distribution of extracellular matrix components in this tumour entity and thus to shed light on its histogenetic origin.〈section xml:id="abs1-1"〉〈title type="main"〉Methods and resultsHistochemical and immunohistochemical analyses were performed for collagen subtypes I, II, III and VI and cartilage proteoglycans in three samples of de-differentiated as well as conventional chondrosarcomas (various grades). In the chondroid tumour areas of de-differentiated chondrosarcoma, typical cartilage matrix components could be detected similar to chondroid areas of grade 1 and 2 conventional chondrosarcomas. In contrast, the tumour matrix of the nonchondroid portions of de-differentiated chondrosarcomas contained matrix molecules which are typical for fibroblastic tissue. This matrix composition was not identical with less differentiated (nonchondroid) areas of grade 2 and 3 conventional chondrosarcomas.〈section xml:id="abs1-2"〉〈title type="main"〉ConclusionsOur results confirm the chondroid nature of the differentiated portion of de-differentiated chondrosarcoma and indicate a nonchondrocytic nature of the nonchondroid portion. De-differentiated chondrosarcoma should not be considered as a ‘de’-differentiated chondrosarcoma (grade 4 neoplasm), but as a tumour entity showing two types of mesenchymal differentiation.
    Materialart: Digitale Medien
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  • 6
    ISSN: 1365-2036
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Aim : To study the efficacy of three pantoprazole-based triple therapy regimens for the eradication of Helicobacter pylori infection and gastric ulcer healing.Methods : In an open, multi-centre, randomized study, 519 H. pylori-positive patients with active gastric ulcer were randomized to receive pantoprazole (40 mg) (P) and two of three antibiotics: clarithromycin (500 mg) (C), metronidazole (500 mg) (M) or amoxicillin (1000 mg) (A). Triple therapy (PAC, PCM, PAM) was administered twice daily for 7 days, followed by pantoprazole until the ulcer had healed. Antrum and corpus biopsies were taken to determine the pattern of gastritis, to assess the H. pylori status and to determine the strain susceptibility to antibiotics, and from the ulcer margins and base to exclude malignancy. Scores based on the Sydney system were used to categorize the gastritis phenotypically.Results : The H. pylori eradication rates for the per protocol (intention-to-treat) analysis were 89% (67%) for PAC, 83% (68%) for PCM and 76% (60%) for PAM, with a significant difference between PAC and PAM. Healing rates after 4 weeks were 91% for PAM, 90% for PCM and 88% for PAC (per protocol analysis). The eradication rates were lower in patients in whom strains resistant to any antibiotic used in the triple therapies were detected. Successful eradication [odds ratio, 5.2 (3.3; 8.3)] and the ulcer size (〈 15 mm) were significant predictors for healing after 4 weeks. The regimens showed a comparable safety profile and compliance.Conclusions : Pantoprazole-based triple therapies are effective in the eradication of H. pylori infection in gastric ulcer patients, as reported in previous similar sized studies in duodenal ulcer patients. Successful eradication and an ulcer size of 〈 15 mm are the best predictors of gastric ulcer healing after 4 weeks.
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Amsterdam : Elsevier
    Physics Letters B 338 (1994), S. 13-19 
    ISSN: 0370-2693
    Quelle: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Thema: Physik
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 8
    ISSN: 0370-2693
    Quelle: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Thema: Physik
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 9
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Science Ltd
    Histopathology 47 (2005), S. 0 
    ISSN: 1365-2559
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 10
    ISSN: 1530-0358
    Schlagwort(e): Beta-catenin ; Immunohistochemistry ; Metastasis ; Predictive value ; Prognosis ; Rectal cancer ; Tumor marker
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract PURPOSE: Adenomatous polyposis coli protein, glycogen synthetase kinase-3-beta, T cell transcription factor/lymphoid enhancer-binding factor, and beta-catenin modulate cell differentiation and proliferation via the expression of effector genes. It has recently been postulated that betacatenin is a potent oncogene of sporadic colorectal carcinogenesis and a prognostic tumor marker. Our aim was to investigate whether the nuclear overexpression of betacatenin, possibly caused by mutations in exon 3 of betacatenin (CTNNB1), is correlated with distant metastatic spread or disease-free survival in rectal carcinoma. METHODS: Immunohistochemical analysis was performed with an anti-beta-catenin-monoclonal antibody on paraffin sections of two groups of patients (n=2 × 77) with rectal carcinoma curatively treated by surgery alone. The patients selected were all free of local disease, to exclude surgical influence. Patient groups were matched for age, gender, International Union Against Cancer stage, and year of operation (1982 to 1991) and differed only in subsequent metachronous distant metastatic spread. Follow-up was prospective (median, 9.6 years). Three staining patterns were defined: membranous (normal), diffuse cytoplasmic (pathologic), and intense nuclear staining (pathologic). When intense nuclear staining was defined, the specimen was microdissected. Then, DNA was isolated, polymerase chain reaction-amplified, and sequenced to detect mutations in exon 3. RESULTS: Nuclear overexpression of beta-catenin correlated neither with distant metastatic spread (chisquared, 0.37;P=0.79) nor with disease-free survival (log-rank with trend,P=0.62). No mutations were found in the area of the serine/threonine-kinase glycogen synthetase kinase-3-beta-phosphorylation site in exon 3 (CTNNB1) of beta-catenin. CONCLUSION: Although beta-catenin seems to play an important role in early colorectal carcinogenesis, its value as a prognostic marker is questionable. It must be assumed that metastatic ability is determined by other factors than the disturbance of the beta-catenin T cell transcription factor/lymphoid enhancer-binding factor cascade and that other mechanisms might cause the observed nuclear translocation of beta-catenin.
    Materialart: Digitale Medien
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