Biomedical subjects

D Hoelzer

Publications and source records attributed to D Hoelzer.

385 records · Page 22Linked to original sources

PubMedDate not supplied

Decreased haematopoietic colony growth in long-term bone marrow cultures of HIV-positive patients.

Deficiencies in bone marrow stromal cells, i.e. fibroblasts, macrophages, endothelial cells and adipocytes, are considered to play a pathophysiological role in HIV-associated haematopoietic failure. Long-term bone marrow cultures (LTBMC) enable the longitudinal investigation of haematopoietic progenitor cell and bone marrow stromal growth. Therefore, in this study, the haematopoietic colony growth of bone marrow from patients with severe HIV infection was compared to that from healthy controls in LTBMC. The total cumulated number of colony-forming units/granulocyte-macrophage (CFU-GM) was 6.7-fold higher (293.6% vs. 44.0%, p < 0.01), that of colony-forming units/granulocyte-erythrocyte-macrophage-megakaryocyte (CFU-GEMM) was 3.5-fold higher (28.7% vs 8.3%), and that of burst-forming units/erythrocyte (BFU-E) was 31.1-fold higher (68.4% vs 2.2%) than that from HIV-positive patients, respectively (colony number before LTBMC = 100%). In contrast, the cumulated cell number at the end of LTBMC from HIV-positive patients was not reduced (cell numbers in percent of initially seeded cells: HIV-positive 418.4%, HIV-negative 397.1%). The significantly reduced colony-forming capacity over a significantly shorter time span, without reduction in the absolute cell number, in LTBMC from patients with severe HIV-infection as compared to healthy controls, suggests that uncoupling between cell proliferation and differentiation is a pathophysiological mechanism in HIV-dependent haematopoietic failure.

Adult↗

PubMedDate not supplied

Meningeosis leukaemica in adult acute lymphoblastic leukaemia.

This review addresses diagnosis of CNS involvement, incidence and treatment of CNS disease at time of diagnosis, prophylaxis and treatment of CNS relapse and risk factors for meningeal recurrence in adult acute lymphoblastic leukaemia (ALL). At the time of diagnosis meningeosis leukaemica is present in about 6% (1-10%) of the adult ALL patients with a higher incidence in ALL subgroups T-ALL (8%) and B-ALL (13 %). With the invention of early additional CNS directed therapy it no longer represents an unfavourable prognostic factor. In the absence of prophylaxis meningeal relapses occur in approximately one third of adults with ALL. A literature review including more than 4000 adult ALL patients showed for the different prophylactic treatment approaches the following CNS relapse rates: intrathecal therapy alone 13% (8-19%), intrathecal therapy and CNS irradiation 15% (6-22%), high dose chemotherapy 14% (10-16%), high dose chemotherapy and intrathecal therapy 8% (2-16%) and high dose chemotherapy, intrathecal therapy together with CNS irradiation 5% (1-12%). It became obvious that the early onset of intrathecal therapy and CNS irradiation and the continuation of intrathecal administrations throughout maintenance are essential. The most favourable results where achieved with high dose chemotherapy combined with intrathecal therapy and/or CNS irradiation. The majority of treatment regimens in adult ALL already include high dose chemotherapy in order to reduce the risk of bone marrow relapse. The outcome of patients with CNS relapse is still poor. Although a remission can be induced in the majority of patients (> 60%) it is usually followed by a bone marrow relapse and the survival is poor (< 5-10%). Bone marrow transplantation might be in adults at present the only curative approach.

Adult↗

PubMedDate not supplied

[Myelodysplastic syndrome: a review].

Myelodysplastic syndromes (MDS) are heterogeneous diseases with cytopenia in the peripheral blood, dysplasia of two or three cell lines, and a low leukemic blast count in the bone marrow and peripheral blood. The syndrome is rare in childhood (1%-2% of all acute leukemias). In the advanced subtypes of MDS with 5% to 30% of blasts the risk of progression into acute leukemia is high, especially in childhood. Cytogenetic abnormalities like monosomy 7 are typical for children with MDS, and probably are an unfavourable prognostic factor. The overall prognosis is almost the same as in adults, with a median survival time of 19 months. There are no well-established therapy strategies in MDS. Intensive chemotherapy may be beneficial, at least in children and young adults, but the decision when to start treatment is difficult. At present allogeneic bone marrow transplantation is the only curative therapy available for MDS.

Bone Marrow↗

PubMedDate not supplied

Liposomal amphotericin B as early empiric antimycotic therapy of pneumonia in granulocytopenic patients.

Twenty-three neutropenic patients with haematological malignancies and febrile pulmonary infiltrates were empirically treated with liposomal amphotericin B (AmBisome) in addition to broad-spectrum antibiotics. AmBisome was given on alternate days in two different dosages: 3 mg kg-1 in patients with pneumonia but without radiological signs or other evidence of Aspergillus infection and 5 mg kg-1 in pneumonia patients with suspected Aspergillus infection. The main objectives of this study were to compare the response and lethality of pneumonias treated early with empirically AmBisome with a historical group (treatment with conventional amphotericin B only in case of proven/highly probable aspergillosis) and to investigate the tolerability and efficacy of AmBisome 5 mg kg-1 in cases of proven/probable aspergilloses. Six out of seven (86%) patients without initially suspected aspergilloses receiving AmBisome 3 mg kg-1 responded completely. Twelve out of 16 patients with initial radiological signs of aspergillosis receiving AmBisome 5 mg kg-1 were evaluable. Body temperature normalized in 10/12 (83%) patients; eight experienced complete and two partial regression of their infiltrations and 9/10 patients with proven/probable aspergillosis responded. Acute AmBisome-related reactions were seen in three patients from each group; loss of potassium was noted in five subjects in each group and slightly increased plasma creatinine was found in two patients in the 5 mg kg-1 group. Altogether, the response of all pneumonia patients treated with early empirical AmBisome compared with the historical group was 17/19 vs. 49/72 (89% vs. 68%, NS); among those with proven/probable aspergilloses 11/12 vs. 7/17 (92% vs. 41%, P = 0.008) patients responded. Pneumonia lethality was 1/19 in the AmBisome-treated patients compared with 23/72 in the historical group (5% vs. 32%, P = 0.01); and among those with proven/probable aspergilloses it was 1/12 vs. 10/17 (8% vs. 59%, P = 0.008). In conclusion, early empiric treatment with AmBisome 3 mg kg-1 and 5 mg kg-1 on alternate days was well tolerated and greatly reduced the lethality of proven/probable Aspergillus pneumonias.

Adult↗

PubMedDate not supplied

Antifungal prophylaxis in neutropenic patients with hematologic malignancies: is there a real benefit?

Invasive fungal infections have been reported with an increasing incidence over the last 20 years. Fungal infections are an important cause of morbidity and mortality in patients with hematological malignancies. Therefore, in neutropenic patients different regimens of antifungal prophylaxis have been performed for more than 20 years, but the effect of antifungal prophylaxis is controversial. A long duration of neutropenia, impaired cell-mediated immunity as well as continuous corticosteroid therapy and sustained immunosuppression for graft-versus-host disease in patients treated with allogeneic bone marrow transplantation are known risk factors for invasive mycosis. Since early diagnosis of invasive fungal infection is difficult, strategies to prevent fungal infections seem to be attractive. The introduction of triazoles have provided us with a better armamentarium to prevent fungal infections. In this review, the current strategies of antifungal prophylaxis are discussed. Antifungal prophylaxis has been effective in reducing candida infection, however, there has been no proven successful prevention of invasive aspergillosis. In addition, there is no clearly proven benefit of antifungal prophylaxis regarding the reduction in the overall mortality. Thus the best way to reduce invasive fungal-related mortality will be early diagnosis and preemptive therapeutic approaches.

Antifungal Agents↗

PubMedDate not supplied

Interleukin-10 expression: is there a neglected contribution of CD8+ T cells in rheumatoid arthritis joints?

OBJECTIVE: To search for RA specific processes among T cell accumulation, T cell activation, or cytokine expression in CD4+ and CD8+ synovial fluid (SF) T cells. METHODS: Flow cytometry of CD4+, CD8+, CD45RA+, CD45RO+, CD69 double or triple stained peripheral blood (PB) and SF T cells. IL-2, IL-10, and IFN-gamma expression was determined in PMA + ionomycin stimulated T cells on the single cell level. Concentrations of secreted IL-2, IL-4, IL-10, and IFN-gamma were quantified in the sera and synovial fluids by enzyme linked immunosorbent assay (ELISA). RESULTS: A preferential recruitment of CD45RO+ memory T cells was found for CD4+ helper T cells, and in similar also for CD8+ suppressor T cells. An elevated CD69 expression was detected in memory, but also in CD45RA+ naive CD4+ and CD8+ SF T cells, whilst IL-2 expression was only demonstrable in a minor proportion of T cells populations. Preferential recruitment of memory T cells, but incomplete activation of naive and memory, CD4+ and CD8+ T cells were in similar found in RA and control patients. In RA but not in the control patients, a relevant proportion of CD4+ and CD8+ PB and SF T cells expressed IL-10 and IFN-gamma. High concentrations of IL-10, that were correlated with the amounts of secreted TNF-alpha, were only detected in RA joints. CONCLUSION: Memory and naive T cell state of CD4+ and CD8+ T cell accumulates in the joints, and early T cell activation occur in similar patterns in RA and control patients. High IL-10 SF concentrations in contrast, and elevated percentages of IFN-gamma and IL-10 expressing CD4+ and CD8+ T cells in the PB and SF were characteristic for RA. Here, CD8+ T cells may contribute to high IL-10 concentrations in RA joints.

Arthritis, Rheumatoid↗

PubMedDate not supplied

In vivo administration of recombinant human interleukin-3 elicits an acute phase response involving endogenous synthesis of interleukin-6.

Interleukin-6 has been shown to stimulate in vitro synthesis of C-reactive protein (CCRP) in hepatocytes by enhancing the transcriptional rate of the CRP gene. It has also been demonstrated that IL-6 spurs the terminal differentiation of B-cells into immunoglobulin secreting cells when synergizing with IL-3. IL-6 may therefore act as a prime molecule in the acute phase and immune response. We have administered rh IL-3 to cancer patients in a phase I/II clinical trial. Endogenous IL-6 levels increased in a dose-dependent fashion upon i.v. bolus injection of rh IL-3 and continued to be significantly elevated above pretreatment levels when IL-3 was further administered by the s.c. route. Increases of IL-6 levels were associated with enhanced production of CRP in vivo detected after 24 h of injection. At day 14 of rh IL-3 treatment plasma immunoglobulin concentrations were measured and IgM was found to be increased by greater than 2.5 fold above starting levels. These results indicate that rh IL-3 also augments the acute phase response in vivo and contributes to increased synthesis of IgM and that induction of endogenous IL-6 is involved in these events.

Acute-Phase Proteins↗