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V Diehl

Publications and source records attributed to V Diehl.

At least 91 records · Page 5Linked to original sources
PubMed2001

Loss of heterozygosity in the Hodgkin-Reed Sternberg cell line L1236.

Hodgkin-Reed Sternberg cells are derived from germinal centre B-cells in most cases. Somatic mutations affecting their rearranged immunoglobulin genes were detected, rendering potential functional rearrangements non-functional. Under physiological conditions such cells would be designated to undergo apoptosis within the germinal centre. In search for the specific transforming event that prevents Hodgkin-Reed Sternberg cells from programmed cell death, cytogenetic analyses were broadly performed but did not reveal specific chromosomal aberrations. Analysis of these cells on the molecular level is difficult to perform due to the scarcity of the cells in the lymphoma tissue and the given limitations of in situ studies. To overcome these limitations, the cell line L1236, known to be derived from Hodgkin-Reed Sternberg cells in situ, was chosen for allelotype analysis. Using a panel of microsatellite loci assigned to nearly all chromosomal arms, regions of loss of heterozygosity were detected on chromosomal arms 6p, 9q and 17p. The size of lost segments was estimated by amplification of additional microsatellite loci mapped to the respective regions. Further analyses of single Hodgkin-Reed Sternberg cells will reveal whether LOH affecting these regions is a recurrent event in HD and to which extent the smallest commonly affected region can be estimated.

Alleles↗
PubMed2001

Immunotherapeutic strategies in neuroblastoma: antitumoral activity of deglycosylated Ricin A conjugated anti-GD2 antibodies and anti-CD3xanti-GD2 bispecific antibodies.

BACKGROUND: The antigen GD2 is selectively expressed on the surface of neuroblastoma cells, and is detected by the monoclonal antibody BW704. In this study, we describe the antitumoral capacity of the immunotoxin BW704dgA (BW704 conjugated to deglycosylated ricin A), and of anti-CD3xanti-GD2 bispecific antibodies that are capable of redirecting cytotoxic T cells towards neuroblastoma cells. We further investigate the in vivo activity of BW704dgA immunotoxins in a human neuroblastoma model in SCID mice. PROCEDURE: BW704dgA immunotoxins were injected i.p. as a single close (48 microg/mouse) on day 4 or divided into three doses on day 4, 5, and 6 after i.v. inoculation of the human neuroblastoma cell line IMR5-75. RESULTS: The mean survival time (MST) of BW704dgA treated animals was significantly increased (MST 49 days) compared to the control animals treated with irrelevant immunotoxin, unconjugated BW704, or control buffer (MST 33 to 39 days, P < 0.0001), without differences in the application schedules. Anti-CD3xanti-NP antibodies and NP-conjugated GD2-antibodies (BW704-NP) were used in a cytotoxicity assay with cytotoxic T-cells as effectors, and tracer labeled neuroblastoma cell line IMR5 as target cells. Anti-CD3xanti-NP antibodies, together with BW704-NP, showed increased cytotoxic activity compared to the incubation with CD3xanti-NP antibodies alone or with unconjugated anti-GD2. Additionally, a dose-dependent effect of NP-conjugated anti-GD2-antibodies upon the lysis of the target cells could be demonstrated. In this report, we describe two immunotherapeutic approaches using GD2 binding BW704 antibodies, modified as immunotoxin and a bispecific antibody, for the targeting and elimination of neuroblastoma cells. CONCLUSIONS: We envisage a combined immunotherapeutic regimen consisting of BW704dgA mediated stem cell purging, followed by a systemic treatment with anti-CD3xanti-GD2 bispecific antibodies in neuroblastoma.

Animals↗
PubMed2001

Cell fusion is not involved in the generation of giant cells in the Hodgkin-Reed Sternberg cell line L1236.

The mechanism of multinucleated cell formation in Hodgkin's disease has not yet been elucidated. We asked whether the giant multinucleated cells of the H-RS cell line L1236 develop via fusion of the predominant smaller cells. As a positive control for the fusion assay, human B cells from the B-cell lymphoma cell line BJA-B were split into two fractions, stained with the fluorochromes CMTMR and CMFDA, respectively, and fused using the polyethylene glycol 1500 cell hybridization protocol. Double-stained cells indicating fusion of BJA-B cells were detectable for up to 5 days. In parallel, L1236 cells were split into two fractions, stained with the fluorochromes, and mixed. No double-stained L1236 cells were detected. The same result was obtained when using FACS-sorted small mononuclear L1236 cells. It is thus concluded that the large multinucleated cells of the monoclonal H-RS cell line L1236 have emerged by endomitosis rather than by spontaneous cell fusion.

Cell Culture Techniques↗
PubMed2001

Hodgkin disease-derived cell lines expressing ubiquitous mitochondrial creatine kinase show growth inhibition by cyclocreatine treatment independent of apoptosis.

Ubiquitous mitochondrial creatine kinase (uMtCK), a key enzyme in energy metabolism, was identified by differential display PCR to be specifically overexpressed in L1236, the first cell line of definite Hodgkin origin. RT-PCR confirmed overexpression of uMtCK in the L1236 cell line and the absence of cytosolic B-CK, which is co-expressed with MtCK physiologically. Cyclocreatine (cCr), whose phosphorylated form is a very poor substrate for CK, inhibited proliferation of the L1236 cell line nearly entirely. This inhibition by cCr was partially reversed by competition with creatine, which by itself had no effect on proliferation of the L1236 cell line. Although these results support a role of CK activity in the inhibitory action of cCr, it remains open whether the cCr effect is due to its inhibition of CK-linked energy metabolism or if alternative mechanisms have to be considered. Because the anti-proliferative effect of cCr was not due to induction of apoptosis, in contrast to most other anticancer agents, treatment with the creatine analogue cCr may represent an advantageous therapeutic approach for cells resistant to programmed cell death.

Antineoplastic Agents↗
PubMed2001

Immunomagnetic enrichment of CD138 positive cells from weakly infiltrated myeloma patients samples enables the determination of the tumor clone specific IgH rearrangement.

In multiple myeloma, the polymerase chain reaction (PCR) of the Ig heavy chain with allele-specific oligonucleotide (ASO) primers is a common and well-described method of identifying the tumor clone in peripheral blood (PB), bone marrow (BM) or leukapheresis products (LA). A factor which is crucial to the detection of clonal Ig rearrangements lies in the 'purity' of the tumor tissue used for the consensus PCR. We describe the application of a method to enrich CD138 positive myeloma cells derived from weakly infiltrated PB-, BM- and LA-samples. These are subjected to immunomagnetic enrichment with the MACS system, using an CD138 antibody directly conjugated to magnetic beads to obtain an enriched tumor cell population and the subsequent amplification of tumor specific IgH rearrangements. We investigated 29 samples (ten PB, ten BM, nine LA) with a median myeloma cell content of 0.5%. The approach led to a median enrichment factor of 118. Tumor-specific rearrangements could be amplified reproducibly from samples containing less than 0.1% myeloma cells.

Consensus Sequence↗
PubMed2001

Randomized controlled monocentric comparison of once daily ceftriaxone with tobramycin and cefotaxime three times daily with tobramycin in neutropenic fever.

A prospective, randomized, controlled monocentric trial was performed to evaluate the efficacy and safety of once daily ceftriaxone 2 g plus tobramycin 5 mg/kg in comparison to cefotaxime 2 g t.i.d. plus tobramycin 5 mg/kg qd in the treatment of neutropenic fever. In cases of fever > or = 38.5 degrees C and a neutrophil count below 1000/microliter, patients with hematological malignancies were assigned to ceftriaxone or cefotaxime, each with tobramycin. The primary endpoint was defined as defervescence < 37.5 degrees C on day 4-6 followed by at least 7 afebrile days. Secondary endpoints were overall response, defined as defervescence on day 25 and toxicity. There were 160 episodes of 114 patients included. Fever of unknown origin accounted for 79 episodes (51%), microbiologically defined infection for 36 (23%), clinically defined infection for 27 (17%), and both clinically and microbiologically defined infection for 14 episodes (9%). On an intent-to-treat basis 156 episodes could be evaluated for the primary endpoint. Ceftriaxone plus tobramycin and cefotaxime plus tobramycin resulted in a primary response in 46.9% and 45.3%, respectively. Overall response was achieved on study day 25 in 87.7% and 80%, respectively. No significant difference in toxicity was observed. Once-daily ceftriaxone plus tobramycin was not inferior to cefotaxime t.i.d. plus tobramycin qd in the empirical treatment of neutropenic fever.

Adult↗
PubMed2001

Primary lymphoma of the conjunctiva--a rare manifestation of indolent non-Hodgkin's lymphoma.

Lymphoid tumours of the conjunctiva are extremely rare. Such tumours can appear as an isolated neoplasm or as part of a systemic disease. We describe the clinical and histopathologic findings of a patient with bilateral conjunctival lymphoma who presented with a 5-year history of chronic conjunctivitis. After clinical staging, including (1) thoracic and abdominal computerised tomography scans, (2) magnetic resonance tomography of the brain and orbita, (3) fibre-optic gastrointestinoscopy, (4) colonoscopy and (5) bone marrow biopsy,.no other foci of the lymphoma were found. The patient received radiation therapy and achieved complete remission. We conclude that conjunctival lymphoma should be included in the differential diagnoses of chronic conjunctivitis. Persisting signs and symptoms of conjunctivitis not responding to standard treatment should prompt biopsy.

Biopsy↗
PubMed2001

Clinical and morphological criteria for the diagnosis of prefibrotic idiopathic (primary) myelofibrosis.

A clinicopathological study was performed to define initial-prefibrotic precursor stages of idiopathic (primary) myelofibrosis (IMF) by presenting laboratory and histological bone marrow features. Contrary to the usually accepted diagnostic requirements for IMF, including bone marrow fibrosis and a leukoerythroblastic blood picture, we found that 80 patients did not completely comply with these criteria. In particular, this cohort displayed no increase in the reticulin-collagen fiber content of the bone marrow at onset. Therefore, these cases were occasionally regarded as unclassifiable chronic myeloproliferative disorders (MPDs), or presumptively as essential thrombocythemia (ET). Patients were characterized by a certain set of clinical parameters comprising a borderline to slight leukocytosis and therapy-refractory anemia, minimal to modest splenomegaly, and often an elevated platelet count. Peripheral blood films revealed, only very sparsely, tear drop cells and a few erythroid and myeloid precursors, but no definite leukoerythroblastic reaction. Bone marrow histopathology was consistent with an increase in cellularity and a prominent left-shifted neutrophil granulopoiesis. Erythropoiesis disclosed a slight reduction with small to medium-sized islets. Megakaryopoiesis was the most prominent diagnostic hallmark to distinguish initial-prefibrotic IMF from the allied subtypes of MPDs. This cell lineage was not only characterized by a conspicuous growth and abnormal clustering, but also by a pronounced deviation from nuclear-cytoplasmic differentiation (dysplastic appearance). Cytological anomalies were compatible with a large variety of size and shape, ranging from giant- to atypical micromegakaryocytes with compact and bulky, cloud-like nuclei, due to a coarse lobulation and a frequent occurrence of naked (denuded) nuclei. Follow-up examinations, including sequential trephine biopsies in 22 patients, revealed a transition into myelofibrosis accompanied by laboratory findings in keeping with manifest IMF. In conclusion, morphological and clinical parameters have been validated by this study, which are consistent with a set of diagnostic criteria to recognize initial or prefibrotic precursor stages of IMF.

Adult↗
PubMed2001

Early-stage Hodgkin's disease.

Treatment of Hodgkin's disease (HD) is strictly dependent on stage. Historically, early-stage HD included the limited stages I, II, and IIIA (according to the Cotswolds modification of the Ann Arbor classsification), whereas advanced HD included stage III with B symptoms and stage IV. It was then observed that early-stage HD with certain clinical risk factors had a significantly worse outcome. As a consequence, several studies defined these patients as suffering from early-stage unfavorable (or intermediate-stage) HD, demanding a more aggressive treatment. The treatment of early-stage HD is changing strikingly. Until recently, extended-field (EF) irradiation has been considered the standard treatment. However, because of the recognition of its high relapse rate and fatal long-term effects, EF radiotherapy is now being abandoned by most study groups. Instead, for favorable early-stage HD, mild chemotherapy for control of occult disease is combined with involved-field (IF) irradiation. In early-stage unfavorable (intermediate) HD, four cycles of chemotherapy plus IF irradiation is accepted as standard treatment.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2001

Dose escalation of cytotoxic drugs using haematopoietic growth factors: a randomized trial to determine the magnitude of increase provided by GM-CSF.

BACKGROUND: The magnitude of chemotherapy dose escalation made possible by the use of recombinant haematopoietic growth factors has not been quantified in a randomized trial. PATIENTS AND METHODS: Patients with refractory or relapsing Hodgkin's disease were randomized to receive the Dexa-BEAM regimen with escalating etoposide doses supported by placebo or granulocyte-macrophage colony-stimulating factor (GM-CSF). Using an adaptive sampling method independently in both arms, the etoposide dose was escalated until the maximal tolerated dose for the first cycle was reached. RESULTS: Thirty patients were randomized to GM-CSF and thirty to placebo. The etoposide dose could be escalated considerably in both treatment arms. Maximal etoposide dose for the first cycle was 1920 mg/m2 for patients receiving GM-CSF and 1160 mg/m2 for patients receiving placebo (P = 0.045 one-sided), corresponding to a 65% higher etoposide dose and a 13% higher dose intensity with GM-CSF. Dose-limiting events were similar in both arms, consisting mainly of prolonged neutropenia and consecutive infections. Treatment efficacy was not different in the two treatment groups. CONCLUSIONS: While GM-CSF permits a somewhat higher dose escalation than placebo, the increase in dose intensity provided by GM-CSF is small. The use of CSF for interval reduction rather than dose escalation is the more effective strategy for dose intensification.

Adolescent↗
PubMed2001

Phase I study of BBR 2778, a new aza-anthracenedione, in advanced or refractory non-Hodgkin's lymphoma.

BACKGROUND: BBR 2778 is a novel aza-anthracenedione showing no cardiotoxicity and superior activity compared to doxorubicin and mitoxantrone in animal models. Objectives of this phase I study included the determination of the maximum tolerated dose (MTD), the dose limiting toxicity (DLT), clinical pharmacokinetics (PK), and antitumor activity. Patients with relapsed or refractory, advanced non-Hodgkin's lymphoma were included. PATIENTS AND METHODS: Patients were treated with a q1w x 3 schedule on the basis of a modified Fibonacci dose escalation method. Seven groups with a total of twenty-six patients were treated at dosages of 5, 10, 16.5, 25, 34, 56 or 84 mg/m2/w, respectively. RESULTS: DLT was observed on the seventh dose level with neutropenia WHO grade 4 in three of six patients. Pharmacokinetic analysis showed a large volume of distribution (13.5-17.5 l/kg), a high plasma clearance (0.65-1.74 l/h/kg) and a long elimination half-life (14.7-31.9 h). Tumor response included three complete remissions and two partial remissions. CONCLUSIONS: Neutropenia is the DLT of the new aza-anthracenedione BBR 2778. The recommend dose is 84 mg/m2 in a q1w x 3 schedule. PK data are consistent with a linear kinetic of BBR 2778 comparable to mitoxantrone. This new drug shows promising activity in intensively pretreated patients with relapsed or refractory NHL. Based on this results, phase II studies with this new compound are underway.

Adult↗
PubMed2001

Male gonadal dysfunction in patients with Hodgkin's disease prior to treatment.

UNLABELLED: Infertility after treatment of patients with Hodgkin's disease (HD) is considered as a side effect of alkylating agent containing chemotherapy regimens. To investigate whether gonadal failure is related primarily to the toxic effect of chemotherapy or rather to the disease itself, we investigated the fertility status before the onset of treatment. PATIENTS AND METHODS: Semen quality and hormonal status were evaluated in 158 patients with first diagnosis of HD enrolled into trials of the German Hodgkin Lymphoma Study Group (GHSG). The median age of the patients was 28 years (range 16-52). Twenty patients (13%) were classified as early stage HD, 63 patients (40%) as intermediate stage, and 75 patients (47%)) as advanced stage according GHSG grading. Sixty-seven patients (42%) showed systemic symptoms. Semen analysis was performed according to WHO guidelines. Follicle-stimulating hormone (FSH) and luteinising hormone (LH) plasma levels were measured by specific double-antibody radio-immune-assay (RIA) methods. RESULTS: Prior to treatment, severe damage of fertility, i.e.. azoospermia and oligoasthenoteratospermia (OAT-syndrome) was found in 13 (8%) and 20 patients (13%), respectively. Thirty-eight patients (24%) had single, i.e., oligo-(O), astheno-(A) or teratospermia-(T), and 40 patients (26%) showed combined damages, i.e., OA, OT or AT. In 47 patients (30%) a normal sperm count was found. Thus, III patients (70%) showed semen abnormalities before the onset of treatment. In a multivariate analysis elevated ESR (P < 0.003) and advanced stage of disease (P < 0.01) could be distinguished as prognostic factors for severe damage of fertility. No correlation was found between pre-therapeutic gonadotropine levels and fertility status. CONCLUSION: Patients with HD have an increased risk for inadequate semen quality even prior to treatment. Infertility is more frequent in patients with elevated ESR and advanced stage of disease. This association demonstrates the predominant influence of the disease on fertility. Assuming HD is the major initial cause for infertility efforts should be made to identify new non-gonadal toxic chemotherapies to be able to regain fertility after effective therapy. Further investigations have to be performed to clarify mechanisms inducing fertility defects in patients with HD.

Adolescent↗
PubMed2001

Prognostic impact of bone marrow erythropoietic precursor cells and myelofibrosis at diagnosis of Ph1+ chronic myelogenous leukaemia--a multicentre study on 495 patients.

A multicentre clinicopathological study was performed on 495 patients with chronic-phase Ph1+ chronic myelogenous leukaemia (CML) to determine bone marrow characteristics that exert a significant impact on survival under standard treatment regimens. Immunohistochemical and morphometric techniques were applied to identify nucleated erythroid precursor cells in the bone marrow and to quantify argyrophilic fibre density. Application of the Sokal index and another recently proposed CML score failed to distinguish three clearly defined risk groups. A borderline increase in fibre content (i.e. doubling of the normal density) and a relevant reduction of medullary erythropoiesis proved to be important predictors for survival, even in low-risk classified patients, according to both clinical scores. With regard to optimal treatment strategies, patients with manifest myelofibrosis showed no significant difference in survival rates under interferon or hydroxyurea treatment. Multivariate analysis confirmed the prognostic value of histological features. A risk model based on three variables (fibre density, erythropoietic precursors and spleen size) was constructed that enabled a distinct discrimination of risk profiles. In conclusion, the presented data provide compelling evidence that bone marrow features at diagnosis exert a significant impact on prognosis in CML. In this context, the generally clinical-based multivariate risk classification can be improved by consideration of morphological variables that are acting independently of treatment modalities.

Adult↗
PubMed2001

Class switch recombination was specifically targeted to immunoglobulin (Ig)G4 or IgA in Hodgkin's disease-derived cell lines.

In T cell-dependent immune responses, class switch recombination occurs in germinal centres. There is now evidence that Hodgkin/Reed-Sternberg cells are derived from germinal centre B cells. Cytokines specifically determine the direction of class switching, i.e the isotype of the new antibodies. We performed restriction analyses and polymerase chain reaction on the immunoglobulin heavy chain loci for five Hodgkin's disease-derived B-cell lines and one Hodgkin's disease-derived T-cell line in order to analyse class switch recombination. In all the B-cell lines, class switch recombination had been targeted to Calpha4 or Calpha1/2. This showed that cell-line precursors had undergone class switching, probably under the influence of TH2 or TH3 cell-derived cytokines. Deletions comprising several constant region genes were observed in cell lines L428, L1236, L591 and KMH2. Karyotype analyses of two of these revealed translocational breakpoints within the immunoglobulin heavy chain gene locus. Our data support the view that a chromosomal instability may occur during class switch recombination in Hodgkin/Reed-Sternberg cells causing chromosomal breaks. Thus, as in other germinal centre B cell-derived lymphomas, the immunoglobulin gene locus may be frequently involved in structural chromosomal aberrations in Hodgkin's disease.

Blotting, Southern↗
PubMed2001

Deregulation of immunoglobulin gene transcription in the Hodgkin-Reed Sternberg cell line L1236.

Hodgkin-Reed Sternberg (H-RS) cells harbour clonal immunoglobulin gene (Ig) rearrangements in almost all cases of classical Hodgkin's disease but lack Ig gene expression. In the H-RS cell line L1236, a somatic mutation of the Ig heavy-chain gene promoter octamer motif has been described as a putative reason for absence of Ig gene expression. We addressed transcriptional activity of this mutated promoter by performing reporter gene studies and gel retardation assays. The results showed that the mutation outside the coding region of the rearranged Ig gene in L1236 cells leads to downregulation of Ig gene expression in H-RS cells.

Gene Rearrangement↗