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Biomedical subjects

V Diehl

Publications and source records attributed to V Diehl.

At least 325 records · Page 18Linked to original sources
PubMed1996

Interleukin 10 inhibits cytokine production of human AML cells.

BACKGROUND: Unlike normal hematopoietic cells leukemic blasts from patients with AML constitutively express cytokines like IL1, GM-CSF and TNF alpha and it has been suggested that these cytokines may regulate growth and differentiation of the malignant cells. IL10 inhibits cytokine production of activated macrophages and T-helper 1 cells. We analysed whether IL10 can also suppress cytokine production and may inhibit growth of AML cells. MATERIALS AND METHODS: AML blasts of 18 patients were purified by immunomagnetic separation and cultured in serum-free medium in the presence of cytokines. The production of cytokines was analysed by ELISA, DNA synthesis by 3H-thymidine incorporation and mRNA expression of cytokine genes by semiquantitative RT-PCR. RESULTS: Our results confirm previous results that AML blasts produce a variety of cytokines such as GM-CSF, IL1 alpha, IL1 beta, IL6 and TNF alpha. AML cells were induced to proliferation by G-CSF, GM-CSF, IL3, IL1 beta and SCF to a different extent. In contrast, IL10 significantly inhibited the cytokine production at the mRNA and protein level and spontaneous thymidine uptake in a dose-dependent way. This inhibition could be abrogated by IL10 specific antibodies. CONCLUSION: These observations suggest an inhibitory effect of IL10 on the proliferation of cultured AML blasts most likely through suppression of endogenous cytokines.

Acute Disease↗
PubMed1996

Polymerase chain reaction for microsporidian DNA in gastrointestinal biopsy specimens of HIV-infected patients.

OBJECTIVE: To study the accuracy of polymerase chain reaction (PCR) for microsporidian DNA in gastrointestinal biopsy specimens of HIV-infected patients for the diagnosis of intestinal microsporidiosis. SETTING: Infectious disease in- and outpatient clinic of a university hospital in Cologne, Germany. PATIENTS: Forty-six HIV-infected patients with diarrhoea. METHODS: PCR and Southern blot hybridization were performed using DNA extracted from intestinal biopsy specimens with primers and probes from the small subunit rRNA gene of Enterocytozoon bieneusi and Septata intestinalis. Histological examination of intestinal biopsy specimens was performed using a fluorescence technique. Transmission electron microscopy of intestinal biopsy specimens was performed in 13 patients. RESULTS: Amplification and Southern blot hybridization with species-specific primers and probes gave positive results in 10 patients for E. bieneusi, and in 10 patients for S. intestinalis. Overall, five cases of double infection with E. bieneusi and S. intestinalis were seen when both primer pairs and probes were used. Histological examination showed microsporidian spores in all 15 cases, but light microscopy was unable to distinguish between species in almost all cases. CONCLUSIONS: PCR detection of microsporidian DNA in intestinal biopsy specimens can be used reliably for the diagnosis of intestinal microsporidiosis in HIV-infected patients and is also useful for species differentiation between microsporidia. Infections with S. intestinalis and double infections with two types of microsporidia appear to be more common than previously described.

AIDS-Related Opportunistic Infections↗
PubMed1996

Ornithine decarboxylase levels in patients with normal colonic mucosa.

We describe a systematic examination of ornithine decarboxylase activity in 120 colonic mucosal samples which were obtained from 20 subjects without colonic disease to establish the normal mean and standard deviation from proximal to distal colon. Ornithine decarboxylase activity was determined by releasing CO2 from DL-[1-14C]ornithine. The mean ornithine decarboxylase levels (CO2 liberated) ranged from 0.26 +/- 0.08 nmol/h.mg protein in the caecum to 0.44 +/- 0.16 nmol/h.mg protein in the rectum. There was no difference between sex and age. Ornithine decarboxylase was not stimulated by guanosine 5'-triphosphate. alpha-Difluoromethylornithine showed an ornithine decarboxylase inhibition of 97.1%. Ornithine decarboxylase activity can be measured with reliable precision and reproducibility. The knowledge of the normal range of ornithine decarboxylase activity in normal human colonic mucosa is necessary for the determination of ornithine decarboxylase activity in pathological findings, especially in malignant transformation.

Adolescent↗
PubMed1996

Apoptosis in acute myeloblastic leukemia: follow-up study on trephine biopsies of the bone marrow.

A clinicopathological study on 87 adult patients presenting with "de novo" acute myeloblastic leukemia (AML) was performed to assess the rate of apoptosis before and during chemotherapy and its predictive impact on clinical course. Evaluation included trephine biopsies of the bone marrow and the situ end-labeling technic (ISEL) for the identification of programmed cell death in large and intact hemopoietic tissue areas. In comparison with a control group of 21 patients without any hematological disorder, morphometric analysis revealed no significantly different numbers of apoptotic cells in AML at the onset of disease and following sequential examinations at intervals ranging between 10 to 19 months. Moreover, the incidence of programmed cell death was not associated with the subgroups of the FAB classification and statistics failed to show a relationship with survival or remission status. In conclusion, these findings are in keeping with the assumption that apoptosis occurs with the same frequency in recovering normal hemopoiesis in complete or partial remission, in manifest AML and relapse. In the latter conditions, enhancement of proliferation is not associated with an increase in the apoptotic index.

Acute Disease↗
PubMed1996

Idiopathic primary osteo-myelofibrosis: a clinico-pathological study on 208 patients with special emphasis on evolution of disease features, differentiation from essential thrombocythemia and variables of prognostic impact.

A retrospective clinico-pathological study was performed on 208 consecutively recruited patients (94 males, 114 females, median age 67 years) with idiopathic (primary) osteo-/ myelofibrosis (IMF). According to bone marrow histology (cellularity) as well as extent (semiquantitative grading) and quality (reticulin/collagen) of myelofibrosis, stages of the disease process were determined. At closure of this study (observation time 65 months) 133 patients were dead and 75 alive and median survival was 56 months. The wide spectrum of clinical signs and symptoms and laboratory data on admission was reflected by a corresponding variety of histological features. Significant differences of hematological values could be calculated between patients with or without early reticulin fibrosis (fiber scores 0 and 1) and advanced fibro-osteosclerotic stages (fiber scores 2 and 3). Evolution of disease features was elicited by longitudinal follow-up studies and sequential bone marrow biopsies. Morphometric assessment of fiber density in patients without preceding chemotherapy revealed an unpredictable and varying progression of myelofibrosis associated with alterations of certain laboratory parameters (hemoglobin level, spleensize, thrombocytosis). Differentiation from essential (primary) thrombocythemia (ET) was required in 25 patients who fulfilled the postulated diagnostic criteria. In fact, this group was consistent with hypercellular, early stages of IMF without relevant reticulin fibrosis and an excessively raised platelet count (> or = 1000 x 10(9)/1). Discrimination was only feasible by regarding histology carefully, particularly abnormalities of megakaryopoiesis and follow-up data. Parameters of predictive value indicating a significant loss in life expectancy in comparison with a sex- and age-adjusted normal population included: age (> or = 60 years), hemoglobin levels (< or = 10 g/dl), thrombocyte count (< or = 600 x 10(9)/1) and the presence of myeloblasts and promyelocytes. Statistical analysis disclosed that in the so-called early stages of IMF without relevant myelofibrosis, findings indicative for extramedullary hemopoiesis or generalization of the disease process exerted an unfavourable influence on survival.

Aged↗
PubMed1996

Uvitex 2B stain for the diagnosis of Isospora belli infections in patients with the acquired immunodeficiency syndrome.

OBJECTIVE: Fluorescent stains with Uvitex 2B or other fluorochromes are widely used today, especially for the diagnosis of microsporidian infections in human immunodeficiency virus (HIV)-infected patients. Our objective was to ascertain whether the fluorescent stain with Uvitex 2B is also able to detect Isospora belli in stool samples and duodenal/bile juice of HIV-infected patients. DESIGN: Case study. SETTING: University hospital of the University of Cologne, Germany. PATIENTS: Two HIV-infected patients with chronic diarrhea who had intestinal infections with I. belli. METHODS: Stool was concentrated by a modified water-ether sedimentation method, and duodenal/bile juice was concentrated by centrifugation. Wet-mount preparations were examined by phase-contrast and bright-field microscopy, and smears were stained with a modified acid-fast stain and a fluorescent stain with Uvitex 2B. RESULTS: Using the fluorescent stain with Uvitex 2B, the oocysts of I. belli stained bright white/blue fluorescent and showed a structure similar to that of the oocysts in acidfast stains. CONCLUSIONS: Staining with Uvitex 2B is a suitable method for the diagnosis of I. belli infections. This technique can be used for the diagnosis of three important gastrointestinal parasites (viz, microsporidia, cryptosporidia, and I. belli) responsible for diarrhea in HIV-infected patients.

AIDS-Related Opportunistic Infections↗
PubMed1996

[Hodgkin disease--pathogenesis and therapy].

Hodgkin's lymphoma exerts characteristics of a true hematopoietic neoplasia as well as of an atypic immune response. In affected lymphatic tissue a minority of malignant Hodgkin-Reed Sternberg [H-RS] cells is surrounded by a majority of reactive, nonmalignant cells. Clinical features and biological studies suggest a pronounced, but inefficient, T-cell response against a yet undefined [viralS/B] target antigen expressed on H-RS cells. The role of the Epstein-Barr virus [EBV] which can be detected in the H-RS cells in about 50% of cases remains to be defined. By micromanipulation of single H-RS cells from frozen sections and subsequent enzymatic amplification of nucleic acids [single cell PCR] for the first time a monoclonal B-cell origin of H-RS cells could be demonstrated in several cases of Hodgkin's disease. Therapeutic strategies in Hodgkin's disease, in contrast to non-Hodgkin's lymphoma, are not based on the histological subtype, but rather on precise determination of the stage of disease. Treatment of choice in limited disease stages without risk factors is radiation therapy. Intermediate stages are treated with combined chemo- and radiation therapy, advanced stages with intensive chemotherapy [subsequent radiation only on bulk tumors]. Thus, about 85% of all patients suffering from Hodgkin's disease, can be cured definitely. High-dose chemotherapy followed by autologous stem cell transplantation in relapsed Hodgkin's lymphoma is currently proofed in clinical studies.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

Hodgkin's disease: from basic science to clinical application.

Although the pathogenesis of Hodgkin's disease is not clear, molecular analyses revealed characteristic features which proved the clonal origin of the disease. EBV injection can be demonstrated in more than 50% of cases at the DNA or protein level. Recently, immunoglobulin gone rearrangements were found in single Hodgkin and Reed-Sternberg cells. These rearrangements may be used as defined markers to detect residual disease after chemotherapy. This is of importance for the treatment of advanced stages, since about 50% of patients in this group will not be cured, and attempts are made to improve treatment results by high-dose chemotherapy. Salvage therapy for relapsed patients including high-dose chemotherapy with autologous stem cell support frequently results in remission although duration is generally short. New immunotherapy strategies with immunotoxins or bispecific antibodies are currently analyzed in clinical studies.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

Interferon therapy, but not busulfan restores normal-sized megakaryopoiesis in CML--a comparative histo- and immunomorphometric study.

To assess possible alterations of megakaryocytes associated with interferon (IFN) and busulfan (BU) therapy of Ph(1+)-CML, an immunohistochemical and morphometric study was performed on trephine biopsies of the bone marrow taken before and at varying intervals during treatment. For the identification of megakaryopoiesis and its endoreduplicative activity the monoclonal antibodies CD61 (anti-platelet glycoprotein IIIa) and PC10 raised against proliferating cell nuclear antigen (PCNA) were used. We compared 60 specimens from 20 patients following IFN alpha-2b administration (in combination with IFN gamma in seven patients) with 57 specimens from 22 patients after monotherapy with BU. A close correlation with clinical follow-up studies revealed that in the IFN-treated group the prevalence of atypical micro-megakaryocytes, usually characterizing CML, was conspicuously reduced in repeatedly taken bone marrow samples. Initially, even an increase in size which was levelled to normal values during maintenance therapy was observed. These features were most prominently expressed in the 13 patients with a complete hematologic and/or partial cytogenetic response. Associated with this phenomenon was a significant enhancement of the PCNA-labelling index which indicated a stimulation of endoreduplicative (endomitotic) activity necessary for achieving normal size and ploidy. In the second group of patients treated by BU these changes were absent. For this reason, our findings are in keeping with the assumption that during IFN treatment, there is at least partial recovery and expansion of a putative normal (Ph1-) megakaryopoiesis. In conclusion, megakaryocyte morphology, i.e. normalization in size, is thought to be a useful indicator to evaluate the response to IFN in CML patients.

Adult↗
PubMed1996

A deletion mutant of Pseudomonas exotoxin-A fused to recombinant human interleukin-9 (rhIL-9-ETA') shows specific cytotoxicity against IL-9-receptor-expressing cell lines.

The receptor for human interleukin-9 (hIL-9) might be a target for selective immunotherapy. It is expressed on a variety of malignant cells, including Hodgkin's lymphoma, non-Hodgkin lymphoma and acute myeloid leukemia (AML). We therefore constructed a new chimeric toxin by fusing hIL-9-cDNA to modified Pseudomonas aeruginosa exotoxin A (ETA'). The binding properties of the new recombinant protein, rhIL-9-ETA', were assessed on different cell lines expressing the hIL-9 receptor. The antitumor potency of rhIL-9-ETA' was evaluated against the Hodgkin-derived cell lines L540Cy, KM-H2 and L1236, the Burkitt lymphoma cell line Daudi, the erythroleukemia cell line K562, and the mastocytoma cell line P815-hIL9R, transfected with hIL-9 receptor cDNA. Recombinant hIL-9-ETA' exhibited potent specific cytotoxic effects against P815-hIL9R, K562 and L1236 cells, inhibiting protein synthesis by 50% (IC50) at concentrations of 0.05, 0.58 and 3 micrograms/ml respectively. The cytotoxic effect was abrogated after addition of polyclonal antibodies against the human IL-9. rhIL-9-ETA' might be of potential use against hIL-9R-expressing malignancies.

ADP Ribose Transferases↗
PubMed1996

Idiotype vaccination strategies against a murine B-cell lymphoma: dendritic cells loaded with idiotype and bispecific idiotype x anti-class II antibodies can protect against tumor growth.

Three strategies were used to evaluate 38C13 B-cell lymphoma-specific idiotype immunization to protect against subsequent lymphoma challenge in C3H/He mice. It was observed that tumor-specific immunity could be induced by immunization with (i) KLH-conjugated 38C13 B-cell lymphoma idiotype in complete Freund's adjuvants (survival rate 80%), (ii) dendritic cells pulsed in vitro with native idiotype protein (survival rate 80%), and (iii) bispecific antibodies composed of B-lymphoma-related idiotype and an MHC class II binding moiety (survival rate 40%). Presentation of idiotype determinants by dendritic cells or bispecific antibody resulted in lymphoma-specific immunity and obviated the requirement for carrier protein or adjuvant. Moreover, primed dendritic cells induced predominant development of a tumor-specific T-cell response. Each of these immunization strategies resulted in long-term survival without the emergence of idiotype variants or the induction of tumor dormancy.

Animals↗
PubMed1995

Use of granulocyte colony-stimulating factor (filgrastim) in the treatment of non-cytotoxic drug-induced agranulocytosis.

Five patients with non-cytotoxic drug-induced agranulocytosis were treated with recombinant human granulocyte-colony-stimulating factor (rh-G-CSF). The drugs involved were dipyrone, captopril, clozapine and carbimazole. Bone marrow examination revealed a depleted granulopoiesis with normal erythro- and megakaryocytopoiesis. After discontinuation of the suspected drug, rh-G-CSF was administered daily at 5 microg/kg subcutaneously. The neutrophil counts were recovered between day 6 and 12 and patients were discharged from hospital shortly afterwards. Compared to data from the literature, the neutrophil recovery appeared to be faster than expected without the use of haematopoietic growth factors. In conclusion, rh-G-CSF at a standard dose of 5 microg/kg seems to be an effective treatment for drug-induced agranulocytosis.

Administration, Cutaneous↗
PubMed1995

Development of new ricin A-chain immunotoxins with potent anti-tumor effects against human Hodgkin cells in vitro and disseminated Hodgkin tumors in SCID mice using high-affinity monoclonal antibodies directed against the CD30 antigen.

The lymphocyte activation marker CD30 has been shown to be an excellent target for the immunotherapy of human Hodgkin's lymphoma. In order to develop new potent immunotoxins (ITs) against CD30, we chemically linked 6 recently described monoclonal antibodies (MAbs) via SMPT to deglycosylated ricin A-chain (dgA). Cross-blocking experiments demonstrated that these MAbs, termed Ki-2 to Ki-7, recognize 3 different clusters on the CD30 antigen: Ki-2, Ki-4, Ki-5 and Ki-7 recognize cluster A; Ki-6 recognizes cluster B; Ki-3 binds to cluster C. Staining of 29 sections of normal human organs revealed no major cross-reactivity of any MAbs tested. Binding to the CD30 antigen on L540Cy Hodgkin cells was assessed by flow cytometry, and demonstrated high affinities for Ki-2, Ki-3 and Ki-4. The concentration giving 50% of the mean fluorescence intensity (MFI50) was 0.58 micrograms/ml to 0.78 micrograms/l. MAbs Ki-5, Ki-6, and Ki-7 bound much more weakly. The staining intensity of the MAbs correlated with the cytotoxicity of the corresponding ITs. Ki-2.dgA, ki-3.dgA and Ki-4.dgA inhibited the protein synthesis of L540Cy cells by 50% at concentrations (IC50) of 3.5 x 10(-10)M to 4.0 x 10(-11)M. The most effective IT, Ki-4dgA, is 5-fold more potent than previously reported CD30 ricin A-chain ITs. Ki-4.dgA was subsequently used for the treatment of disseminated human Hodgkin's lymphoma in a SCID mouse model. The mean survival time (MST) of lymphoma-bearing SCID mice was extended from 42 days in untreated controls to more than 132 days when Ki-4.dgA was applied one day after tumor challenge. Ki-4.dgA is a new potent IT suitable for further evaluation against Hodgkin's lymphoma in man.

Animals↗
PubMed1995

Cocktails of ricin A-chain immunotoxins against different antigens on Hodgkin and Sternberg-Reed cells have superior anti-tumor effects against H-RS cells in vitro and solid Hodgkin tumors in mice.

Three ricin A-chain immunotoxins (ITs) recognizing different antigens on Hodgkin-Reed/Sternberg (H-RS) cells were evaluated for their anti-tumor effects when used in combination as "cocktails". These ITs, BB10.dgA (CD25), HRS3.dgA (CD30), and IRac.dgA (70 kDa), strongly inhibited the growth of L540Cy H-RS cells in vitro. The protein synthesis of this cell line was reduced more efficiently by the combination of 2 of these ITs than by BB10.dgA, HRS3.dgA or IRac.dgA alone. A cocktail of all 3 ITs was most effective in vitro. This was at least in part due to the non-homogeneous distribution of CD25, CD30 or IRac on the L540Cy H-RS target cells and to the fact that subpopulations deficient in one antigen nevertheless expressed appreciable levels of the other target antigens. IT cocktails were also superior as anti-tumor agents in nude mice with solid L540Cy tumors. Ninety percent of mice treated with cocktails containing 2 or 3 ITs had continuous complete remissions (CCR), as compared with only 40% of mice treated with the same dose of a single IT. Analysis of 7 L540Cy sub-lines re-established ex vivo from mice that relapsed after having achieved complete remission (CR) after therapy with a single IT showed that the surviving tumor cells were antigen-deficient variants which were resistant to the original IT, but which could be killed by ITs directed against other target antigens. Thus, IT cocktails give superior results against human H-RS cells, both in vitro and in vivo.

Animals↗
PubMed1995

[Prognostic relevance of oncologic after-care].

Follow-up programs in oncology after potentially curative therapy intent to detect recurrent cancer, to initiate a new curative therapy, to detect side-effects and secondary cancer. The prognostic relevance of follow-up in oncology can be defined as the rate of asymptomatic detected potentially curable recurrences. Follow-up programs of different tumors usually combine various diagnostic methods in a standardized schedule. The prognostic relevance of this follow-up programs is investigated in only very few studies. While efficacy of the follow-up in gastro-intestinal cancer must be questioned, follow-up in non-seminomatous germ cell cancer has proven to be effective. This shows that global statements about prognostic relevance of follow-up can not be made. It is therefore necessary to investigate the actual follow-up programs in clinical studies whether they are effective to improve the prognosis in cancer patients. Where the actual programs fail to be effective new risk-adapted follow-up concepts must be created. New approaches in diagnosis and treatment of cancer have to tested whether they can improve the effect of follow-up programs.

Aftercare↗
PubMed1995

Selective loss of integrated Epstein-Barr virus genomes after long-term cultivation of Burkitt's lymphoma x B-lymphoblastoid cell hybrids due to chromatin instability at the integration site.

Independently established somatic cell hybrid clones between the Burkitt's lymphoma (BL) cell line BL 60 and the autologous Epstein-Barr virus (EBV)-immortalized lymphoblastoid cell line (LCL) IARC 277 were analyzed with regard to physical state of EBV and karyotype changes in long-term culture. Early after fusion these hybrids carry EBV genomes of the parental BL cell line integrated near the breakpoint of a translocation chromosome der(19) t(11;19) as well as episomal viral DNA molecules of the parental LCL. During long-term culture, however, all hybrid cell lines lost the integrated EBV sequences and retained exclusively episomal EBV, whereas in parental BL cells the EBV genomes remained stably integrated. Loss of integrated EBV in all cases resulted from a break proximal to the EBV integration site. Fluorescence in situ hybridization revealed that this integration site had become a gap-like chromatin area. We thus conclude that the integration of the EBV genomes constitutes a chromosomal region prone to break events akin to the phenomenon of fragile sites. This instability might have led directly to the loss of the EBV DNA itself and of the chromosome 11 region distal to it.

B-Lymphocytes↗