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Biomedical subjects

B Emmerich

Publications and source records attributed to B Emmerich.

At least 55 records · Page 3Linked to original sources
PubMed1997

Liposomal 1,25 (OH)2 vitamin D3 compounds block proliferation and induce differentiation in myelomonocytic leukaemia cells.

The vitamin D3 derived hormone 1.25 (OH)2 vitamin D3 (1,25 D3) is able to induce growth arrest and differentiation in myelomonocytic leukaemia cells. In order to allow for specific delivery to leukaemic cells the lipophilic compound was incorporated into the lipid membranes of liposomes. Liposomal 1.25 D3 reduced proliferation as measured by 3H-thymidine incorporation in HL60 leukaemia cells by up to 60%. When liposomes were prepared at different concentrations of 1,25 D3 65% inhibition was achieved at 48 nM. The MC 1288 stereoisomer of 1,25 D3 was more potent and had the same activity at 4.8 nM. The effect of the liposomal compounds was specific to myeloid cells as they reduced proliferation in myelomonocytic HL60, monoblastic U937 and monocytic Mono Mac 6 cells but not in the T-cell lines Jurkat and Molt 4. The antiproliferative effect of liposomal 1,25 D3 was associated with an induction of differentiation since treated HL60 cells showed a monocytic morphology, increased expression of CD14 and decreased expression of CD33. When peripheral blood leukaemic cells from M4 and M5 acute myeloid leukaemia (AML) patients were admixed with liposomal compounds an antiproliferative effect was seen in all five cases, including the two cases where free compounds led to enhanced growth. Liposomal delivery of 1,25 (OH)2 vitamin D3 may offer a novel approach to treatment of myelomonocytic leukaemia.

Cell Differentiation↗
PubMed1997

Defects of beta 2-adrenergic signal transduction in chronic lymphocytic leukaemia: relationship to disease progression.

The second messenger 3':5'-cyclic adenosine monophosphate (cAMP) inhibits the proliferation of human B lymphocytes. In lymphoid malignancies, cAMP levels or the number of beta 2-adrenergic receptors seem to be decreased. In order to explore this phenomenon further, the function of the beta 2-adrenergic receptor complex was examined in mononuclear leucocytes (MNLs) from patients with B-cell chronic lymphocytic leukaemia (CLL). Peripheral blood MNLs from 25 CLL patients (16 male, nine female: aged 62 +/- 9 years) and 10 healthy volunteers (seven male, three female; aged 47 +/- 19 years) were used. The binding characteristics of beta 2-adrenergic receptors (beta 2-AR) on MNLs were determined by radioligand binding assays with [125I]-cyanopindolol ([125I]-CYP). The number of high-affinity binding sites for [125I]-CYP was significantly lower in CLL patients (313 +/- 300 sites per cell; mean +/- SD) than in control subjects (1479 +/- 1268 sites per cell). Moreover, the density of beta 2-AR decreased with disease progression, from Binet stage A (371 +/- 236, n = 13) to B (236 +/- 136, n = 7) and C (141 +/- 59, n = 5) (P < 0.05; Kruskal-Wallis analysis). Functional analyses of the beta 2-AR complex were performed by measuring the cellular cAMP content of MNLs in response to different stimulators. The cAMP production of MNLs upon isoprenaline stimulation (ISO; 10 min, 10(-4) mol L-1) was slightly lower in CLL patients (12.5 +/- 7.04 pmol 10(-6) cells) than in control subjects (15.91 +/- 10.08 pmol 10(-6) cells), and decreased with CLL progression (stage A 14 +/- 7; stage B 13.66 +/- 3.91; stage C 3.07 +/- 0.79 pmol 10(-6) cells). In contrast, cAMP accumulation in response to cholera toxin (CHO; 10(-4) gml-1, 120 min) was not different in control subjects (70.07 +/- 31.30 pmol 10(-6) cells) and CLL patients (stage A 95.24 +/- 123.07, stage B 70.76 +/- 57.37, stage C 33.21 +/- 33.73 pmol 10(-6) cells). When stimulated with forskolin (100 mumol L-1, 15 min), control MNLs produced about ten-fold more cAMP than CLL MNLs (188.56 +/- 92.53 vs. 17.88 +/- 10.32 pmol 10(-6) cells); this response was not stage dependent. Taken together, the results show that the beta 2-AR transmembrane signalling is impaired in CLL patients. The correlation of some beta 2-AR signalling defects with disease progression suggests that they may contribute to the disease progression of CLL patients.

Adult↗
PubMed1997

Serum levels of soluble CD23, but not soluble CD25, predict disease progression in early stage B-cell chronic lymphocytic leukemia.

Serum levels of the soluble forms of CD23 (sCD23) and CD25 (sCD25) were prospectively analyzed with respect to their prognostic relevance in early stage B-cell chronic lymphocytic leukemia (B-CLL). SCD23 and sCD25 levels were determined in 105 patients with newly diagnosed B-CLL (Binet stage A). In 93 of the patients, these levels were correlated with other already established indicators for risk of disease progression, including the histologic pattern of bone marrow infiltration, lymphocyte doubling time (LDT), and the serum level of thymidine kinase (TK). High serum levels of both sCD23 and of sCD25 were associated with a diffuse bone marrow infiltration, a LDT < or = 12 months, and elevated (>5 U/L) serum TK, respectively. Moreover, examination of the clinical course of 76 untreated patients showed that high levels of sCD23, but not of sCD25, at initial diagnosis were linked with disease progression. Furthermore, in a stepwise Cox regression model, high levels of sCD23 and a short LDT were shown to be strong predictors of progressive disease within the first year of disease presentation. Therefore, it appears to be justified to incorporate sCD23 levels into the risk profile of early stage B-CLL and to take them into account for stratification in risk-adapted treatment strategies.

Biomarkers, Tumor↗
PubMed1997

Prognostic factors in chronic lymphocytic leukemia.

The clinical course of chronic lymphocytic leukemia (CLL) shows a marked heterogeneity, with a median survival ranging from 2 to 20 years at different disease stages. This unpredictable course has inspired clinical hematologists and oncologists to search for parameters which predict survival and disease progression. This effort resulted in different staging systems, two of which, the Rai and Binet staging systems, have become most popular because of their simplicity. They identify three major groups of patients with different survival. Since patients at early stages have a relatively good prognosis, only advanced stages used to be treated by chemotherapy with alkylating agents. With the advent of potentially curative, but more aggressive treatment options for CLL, additional prognostic criteria are required to predict the outcome more precisely, in particular in young patients with early disease. It is the intent of this review to summarize the current knowledge on both established and new prognostic factors in CLL, some of which might help to define risk-adapted treatment protocols in the near future.

Age Factors↗
PubMed1997

Complementary anchor PCR of rearranged variable T-cell receptor beta-chain cDNA regions.

Sequencible amplificates comprising the variable cDNA sequences of the rearranged T-cell receptor (TCR) beta-chain were obtained from the T-leukemia cell line Jurkat using a single-sided PCR approach based on five synthetic oligonucleotides derived from the flanking constant sequence. Double-stranded cDNA was cleaved by a restriction enzyme creating cohesive ends, to which an anchor oligonucleotide was ligated. Since this anchor was complementary to the antisense strand of the known constant region, exclusively the desired ligation product folded into a stem-loop-structure that was enzymatically extended to yield a PCR template, now flanked at both ends by primer binding sites appropriate for nested PCR.

Binding Sites↗
PubMed1997

Signal transduction of interleukin-6 involves tyrosine phosphorylation of multiple cytosolic proteins and activation of Src-family kinases Fyn, Hck, and Lyn in multiple myeloma cell lines.

Binding of interleukin-6 to its receptor (IL-6R) induces the association of the IL-6R alpha chain (IL-6Ralpha) with a 130-kDa transmembrane glycoprotein, gp130. This event activates tyrosine kinases of the Janus kinase (JAK) family and transduces signals to the cytosol or nucleus. To further characterize the biochemical mechanisms by which IL-6 promotes cell proliferation, we investigated the effects of IL-6 on the growth and transmembrane signaling of several lymphoid cell lines. In the IL-6-dependent cell line B-9, IL-6 induced a rapid, transient, and concentration-dependent tyrosine phosphorylation of several cytosolic proteins as detected by antiphosphotyrosine immunoblots. The molecular weight of major bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis was 44, 65, 70, 80, 137, 148, 184, and 190 kDa, respectively. Similar effects of IL-6 on tyrosine phosphorylation were observed in the human multiple myeloma cell line LP-1. Because JAKs were unlikely to mediate all the biological effects of IL-6, we investigated whether members of the Src family of tyrosine kinases were also activated in B-9 or LP-1 cells. IL-6 induced the activation and tyrosine phosphorylation of p59Fyn, p56/59Hck, and p56Lyn. Coprecipitation experiments with anti-Hck, anti-Lyn, anti-Fyn, and anti-gp130 antibodies revealed a physical association with gp130 of p56/59Hck and p56Lyn, but not p59Fyn, in LP-1 cells. Together, these results show for the first time that several Src kinases may become activated by IL-6 (p59Fyn, p56/59Hck, and p56Lyn) and associate with gp130 (p56/59Hck and p56Lyn).

B-Lymphocytes↗
PubMed1996

Cisplatin based chemotherapy in testicular cancer patients: long term platinum excretion and clinical effects.

Patients with advanced testicular cancer (TC) have a very good long-term prognosis owing to cisplatin-based polychemotherapy. Platinum is believed to be excreted at a rapid rate via urine within weeks after chemotherapy. As a new, highly sensitive method has become available detecting even natural background platinum levels in body fluids, this study was set up to analyze urinary and serum platinum levels in long-term survivors of testicular neoplasm after cisplatin based polychemotherapy and to correlate clinical data with urinary and serum platinum levels. Urinary platinum concentrations were measured in 64 healthy controls (C) and 22 male patients (TC) 150 to 3022 days after the last application of i.v. cisplatin using voltammetry after UV-photolysis. In the latter group (TC), serum platinum levels were measured as well. Clinical data were analysed as to long-term organ toxicity. Mean urinary platinum levels were 2700 times higher in the patient group (TC) than natural background noise (p < 0.0001). There was a decline of urinary and serum platinum levels over time, being significantly above normal even 8 years after cisplatin exposure. The only significant variables related to the urine platinum concentration were a) the interval between the last i.v. cisplatin application and time of study and b) the total dose given. Not significant were the number of chemotherapy cycles, pre-therapy renal disease, patient age, tumour resection before/after chemotherapy, site of pre/post therapy resection, clinical staging, histological subtypes or tumour markers. Post-therapy renal disease or peripheral nerve damage were not significantly associated with urinary platinum levels. Our data indicate that even 8 years after cisplatin based chemotherapy 500 times elevated urinary and serum platinum levels can be measured in testicular cancer patients. No organ toxicity related to long-term platinum excretion could be detected. This may be due to our small sample size.

Adult↗
PubMed1996

Activation of Src kinases p53/56lyn and p59hck by p210bcr/abl in myeloid cells.

Chronic myeloid leukemia is characterized by the Philadelphia (Ph1) translocation t(9;22) that generates a hybrid gene, bcr/abl, translated to a Mr210,000 tyrosine kinase (p210bcr/abl) with transforming activity for hematopoietic cells. Hematopoietic cell transformation by p2l0bcr/abl seems to involve activation of the Ras signaling pathway by at least two different signaling intermediates, growth factor receptor-bound protein 2 and Src homology and collagen protein, but additional signaling proteins are likely to be required as well. In an effort to identify additional phosphoproteins activated by p210bcr/abl, we studied the murine, interleukin 3-dependent, myeloid cell line, 32D, and a bcr/abl-transfected, factor-independent subline, 32Dp210. The analysis of whole-cell lysates of 32D and 32Dp210 cells showed that several proteins with a molecular weight of Mr50,000-60,000 were phosphorylated on tyrosine residues in 32Dp210 cells. Because Src family kinases have an apparent molecular weight of Mr50,000-60,000, we asked whether they could become activated by p2l0bcr/abl. Two Src family kinases, p53/56lyn and p59hck, showed a severalfold higher phosphokinase activity in 32Dp210 cells than in 32D cells. Coimmunoprecipitation experiments with anti-Lyn, anti-Hck, and anti-Abl antibodies demonstrated an intracellular association of p210bcr/abl with p53/56lyn and p59hck. Moreover, the phosphokinase activity of p53/56lyn was higher in bcr/abl-positive myeloid cell lines (K562, BV173, and LAMA84) than in the bcr/abl-negative myeloid cell line JOSK-M. In conclusion, the results show that p210bcr/abl induces the activation of at least two Src family kinases, P53/56lyn and p59hck, in myeloid cells. These findings extend the range of potential targets of p210bcr/abl that might mediate its transforming effects.

Cytosol↗
PubMed1996

Multicentre prospective randomised trial of fludarabine versus cyclophosphamide, doxorubicin, and prednisone (CAP) for treatment of advanced-stage chronic lymphocytic leukaemia. The French Cooperative Group on CLL.

BACKGROUND: Fludarabine seems to be a promising treatment for patients with advanced chronic lymphocytic leukaemia (CLL). We compared fludarabine therapy with the combination of cyclophosphamide, doxorubicin, and prednisone (CAP) for treatment of CLL in a randomised, multicentre prospective trial. METHODS: Patients older than 18 years of age were entered into the study if they presented with previously untreated B-cell lineage CLL (B-CLL) of Binet stages B or C or relapsed B-CLL pretreated with chorambucil or similar non-anthracycline-containing regimens. Patients were randomly assigned to either fludarabine (25 mg/m2 per day on days 1-5) or CAP (cyclophosphamide 750 mg/m2 per day and doxorubicin 50 mg/m2 per day on day 1, and prednisone 40 mg/m2 per day on days 1-5), both given for six courses. FINDINGS: Of 196 evaluable patients, 100 were previously untreated whereas 96 patients had received prior therapy. Remission rates were significantly higher after fludarabine than CAP, with overall response rates of 60% and 44%, respectively (p = 0.023). A higher response rate to fludarabine was observed in both untreated (71% vs 60%, p = 0.26) and pretreated (48% vs 27%, p = 0.036) cases, although the difference was statistically significant only in pretreated cases. In the latter group, remission duration and survival did not differ between treatment groups with a median remission duration of 324 days after fludarabine and 179 days after CAP (p = 0.22) and median survival times of 728 days and 731 days, respectively. In untreated cases, on the other hand, fludarabine induced significantly longer remissions than CAP with the median not yet reached after fludarabine and a median of 208 days after CAP (p < 0.001). This effect also translated into a tendency towards longer overall survival after fludarabine (p = 0.087). Treatment-associated side-effects consisted in both regimens of predominantly myelosuppression and in particular granulocytopenia. CAP-treated patients had a higher frequency and severity of nausea and vomiting (25% vs 5%, p < 0.001) and alopecia (65% vs 2%, p < 0.001). INTERPRETATION: Fludarabine provided an effective and well-tolerated therapy for patients with advanced CLL, which compared favourably with CAP as one of the most effective standard regimens. In second-line therapy, fludarabine induced a significantly higher rate of complete and partial remissions, while in first-line therapy a significant prolongation of remission was obtained, which may translate into an improvement of overall survival.

Agranulocytosis↗
PubMed1996

Interleukin-6 induces tyrosine phosphorylation of the Ras activating protein Shc, and its complex formation with Grb2 in the human multiple myeloma cell line LP-1.

Like many other cytokines and growth factors, interleukin-6 (IL-6) activates p21ras. However, the precise biochemical mechanisms inducing this activation are unknown. Therefore, we investigated the effects of IL-6 on some recently identified signaling intermediates, Shc (Src homology and collagen) and Grb2 (growth factor receptor bound protein 2), known to activate p21ras. In the multiple myeloma cell line LP-1, IL-6 stimulated the tyrosine phosphorylation of Shc in a time- and concentration-dependent manner. This led to the complex formulation of Shc with Grb2, an adaptor protein known to relocate a p21ras-GDP exchange factor. Sos1 (Son-of-sevenless), to the cell membrane. Taken together, these findings suggest that IL-6 might activate the Ras signaling pathway via tyrosine phosphorylation of Shc and subsequent recruitment of Grb2. Further studies will elucidate which of the IL-6 receptor associated non-receptor tyrosine kinases of the Src kinase or Janus kinase family, mediate these effects.

Adaptor Proteins, Signal Transducing↗
PubMed1996

Interaction of the receptor tyrosine kinase p145c-kit with the p210bcr/abl kinase in myeloid cells.

The chimaeric bcr/abl oncogene is detected in virtually all cases of chronic myelogenous leukaemia (CML). It encodes a constitutively active tyrosine kinase of 210 kDalton, p210bcr/abl, which stimulates a variety of cytosolic signalling intermediates. The effects of bcr/abl on the activity of growth factor receptors are less well known. In order to investigate interaction of p210bcr/abl with the receptor tyrosine kinase p145c-kit, we used two myeloid, factor-dependent cell lines, MO7 and 32D, to generate bcr/abl positive sublines, MO7p210 and 32Dp210, by transfection with the bcr/abl gene. Since 32D and 32Dp210 cells did not express p145c-kit, a c-kit retrovirus was used to generate c-kit positive cell lines (32Dkit, 32Dp210kit). In contrast to MO7 and 32Dkit cells, MO7p210 and 32Dp210kit cells were factor independent and did not respond to the growth-promoting effects of recombinant human Steel factor (rhSF). Preincubation with a monoclonal antibody (MAb) neutralizing the binding of SF to p145c-kit did not affect the growth of MO7p210 cells, thus eliminating the possibility of an autocrine SF secretion. 32Dkit cells transfected with bcr/abl containing an inactivating point mutation (Lys-->Arg271) in the Abl kinase domain (32Dp210(Arg271)kit) retained their responsiveness to the effects of rhSF. Immune complex kinase assays showed that the kinase activity of p145c-kit was several-fold higher in MO7p210 and 32Dp210kit cells than in MO7, 32Dkit and 32Dp210(Arg271)kit cells, suggesting that Abl kinase activity was necessary to activate p145c-kit. Co-immunoprecipitation experiments with anti-Kit and anti-Abl MAbs demonstrated that p145c-kit and p210bcr/abl were associated in an intracellular complex in human bcr/abl positive, c-kit positive cell lines (MO7p210; GM/SO). Finally, colony assays with bone marrow from bcr/abl positive CML patients showed that the haemopoietic progenitors of three of four patients did not respond to rhSF. Taken together, the results suggest that p145c-kit can be activated by p210bcr/abl via an Abl-kinase dependent mechanism involving the complex formation of both proteins. These findings could explain some clinical features (basophilia, increase of immature myeloid cells) of chronic-phase CML.

Cell Division↗
PubMed1996

Interferon-alpha 2b (IFN alpha) for early-phase chronic lymphocytic leukaemia with high risk for disease progression: results of a randomized multicentre study.

The efficacy of interferon-alpha 2b (IFN alpha) to prolong progression-free (PFS) and/or overall survival (OS) in early B-CLL (Binet stage A) was examined in a risk-adapted phase III study. 99 previously untreated B-CLL patients were recruited. 44 patients with expected high risk for disease progression, defined by non-nodular bone marrow infiltration and lymphocyte doubling time < or = 12 months or serum thymidine kinase levels > or = 5 U/I, were randomized to either receive IFN alpha (group 1, n = 21) or not (group 2, n = 23). 55 low-risk patients were observed to evaluate this risk stratification (group 3). During a median observation time of 36 months, four patients in the IFN alpha group achieved a partial remission (PR), no patient had stable disease (SD), and 17 patients experienced progressive disease (PD). The four responders had less extensive disease at study entry and tended to exhibit a rise in serum IgG levels. In group 2, no PR, seven SD and 16 PD, whereas in group 3, no PR, 37 SD and 18 PD occurred. PFS in group 1 (6.7 months) was not different from group 2 (13.3 months, P = 0.22), but PFS of groups 1 and 2 differed from group 3 (37 months, P < or = 0.001). OS was 44.9 months (group 1), 43.1 months (group 2) and 57.9 months (group 3). OS was not significantly different for group 1 v 2, but was significant between groups 1 and 3 (P = 0.023). The higher percentage of PD in group 2 compared to group 3 (70% v 29%) shows that the selected risk factors allow the definition of CLL stage A patients at risk for disease progression within about a year. In conclusion, our data indicate that IFN alpha does not prolong PFS or OS in stage A CLL patients with high risk for disease progression.

Aged↗
PubMed1996

Serum beta(2)-microglobulin and serum thymidine kinase are independent predictors of progression-free survival in chronic lymphocytic leukemia and immunocytoma.

Chronic lymphocytic leukemia (CLL) and immunocytoma (IC) are remarkably heterogeneous with regard to their clinical course. The current staging systems can distinguish prognostic subgroups, but do not seem to predict the risk of disease progression of an individual patient with sufficient accuracy. Given the increase of treatment options for CLL and IC, additional parameters are needed to decide which patients may benefit from early or intensified treatment. It has been shown that two biochemical markers, serum beta 2-microglobulin (s-beta 2M) and serum thymidine kinase (s-TK), might identify CLL and IC patients at high risk of disease progression. Therefore, the prognostic value of these two serum parameters was compared with a panel of several established prognostic factors in a prospective clinical trial. 113 patients with CLL and 41 patients with IC (mean age +/- SD 63.9 +/- 10.7 years) were included. The following parameters were determined: histopathological diagnosis (IC vs. CLL), age, sex, performance status (Karnofsky index), B symptoms, peripheral blood lymphocyte count, platelet count, blood hemoglobin, serum lactate dehydrogenase (s-LDH), s-beta 2M, s-TK, serum creatinine, number of lymph node areas involved, prior therapy, and the time from diagnosis to inclusion in the study. Univariate analyses showed that nine parameters (Karnofsky index, peripheral blood lymphocytosis, platelet count, blood hemoglobin, lymph node areas involved, pretreatment, s-LDH, s-beta 2M, and s-TK) significantly predicted progression-free survival. In a Cox regression model, only four of these parameters provided independent prognostic information on progression-free survival: 1. s-beta 2M, 2. Karnofsky index, 3. platelet count, and 4. s-TK. The results show that s-beta 2M and s-TK independently predict progression-free survival in patients with CLL and IC, and suggest that these prognostic factors may allow an improved prediction of progression-free survival, particularly in early disease stages.

Biomarkers, Tumor↗
PubMed1996

Target value tailored (TVT) apheresis approach for blood progenitor cell collection after high-dose chemotherapy and rh-G-CSF.

Twenty-eight patients with different hematological diseases (17 non-Hodgkin's lymphoma, one Hodgkin's disease and 10 multiple myeloma) underwent peripheral blood progenitor cell (PBPC) collection after cyclophosphamide 7 g/m2 and rh-G-CSF. Fifty-eight leukaphereses were carried out with a fully automated PBPC collection procedure. Progenitor cell release was monitored by standardized determination of CD34+ cells in the peripheral blood. After a profound aplasia, a continuous increase in CD34+ cells in the peripheral blood was seen for at least 3-4 days. In 82% of our patients more than 2.5 x 10(6) CD34/kg could be collected using a standard apheresis of 10 l. There was a high correlation between the CD34+ cells in the peripheral blood and CD34+ cells/kg harvested. (r2 = 0.91). A relatively constant ratio (median 14.3, range 3.2-22.6) was found between CD34+ cells/kg and CFU-GM/kg. Based on the CD34 values of the pre-apheresis blood and the body weight of an individual patient and using the mathematical model of regression analysis (y = mx + b) for the correlation between the CD34+ cells/microliter in the pre-apheresis blood and the CD34+ cells/kg, it was possible to create a formula allowing for target value tailored apheresis. Using this formula, the blood volume which needs to be processed in order to harvest a desired number of CD34+ cells/kg can be calculated. This strategy can be applied to reduce the time for and the number of aphereses. Nineteen leukaphereses were carried out applying the formula. In 18 of 19 leukaphereses the expected CD34+/kg values were correctly achieved or exceeded. The formula was most reliable when the CD34 value was higher than 15/microliter and when the WBC count was below 20 x 10(9)/l in the pre-apheresis blood. For mobilizations using hematopoietic growth factors alone our formula is not applicable, because in most cases the pre-apheresis white blood cell count is higher than 20 x 10(9)/l and the collection efficacy of lymphomonocytoid cells decreases with a high pre-apheresis white blood cell count. The formula also works with other mobilization regimens that induce a pronounced aplasia.

Antigens, CD34↗
PubMed1995

CD30 ligand signal transduction involves activation of a tyrosine kinase and of mitogen-activated protein kinase in a Hodgkin's lymphoma cell line.

CD30 is a transmembrane receptor of the nerve growth factor/tumor necrosis factor receptor superfamily. Its expression associated with Hodgkin's lymphoma and a subset of non-Hodgkin's lymphoma. Recently, its ligand (CD30L) has been cloned. CD30L enhances the proliferation of peripheral T cells and the Hodgkin's cell line HDLM-2 but seems to exert antiproliferative effects on large cell anaplastic lymphoma cell lines. Since tyrosine kinases are critical regulators of cell growth, we investigated whether CD30L induced changes in cellular tyrosine phosphorylation in CD30-positive lymphoma cell lines. Stimulation with CD30L or with an agonistic mAb against CD30, M44, induced a rapid, transient, and concentration-dependent tyrosine phosphorylation of a cytosolic protein of M(r) 42,000 (p42) in the Hodgkin's lymphomas cell line HDLM-2 but not in other CD30-positive lymphomas. In HDLM-2 cells, the phrobol ester phorbol 12-myristate 13-acetate also stimulated tyrosine phosphorylation of p42, and this effect was enhanced by M44. In marked contrast, agents stimulating the protein kinase A pathway, like forskolin or dibutyryl cAMP, did not affect tyrosine phosphorylation of P42. By immunoprecipitation with mAbs against mitogen-activated protein kinase (MAPK; p42ERKII), a M(r) 42,000 protein was identified which comigrated with p42 on SDS gels and which was phosphorylated on tyrosine residues in response to stimulation of CD30. Immune complex kinase assays showed that M44 mAb induced the activation of MAPK (p42ERKII) and the phosphorylation of a MAPK substrate, myelin basic protein. Taken together, the results suggest that CD30L induces the tyrosine phosphorylation and activation of the MAPK p42ERKII isoform in HDLM-2 cells. These findings may have implications for the understanding of the pathogenesis of Hodgkin's disease.

CD30 Ligand↗
PubMed1995

[Vaso-occlusive crises in sickle-cell anemia].

HISTORY AND FINDINGS: Severe pain suddenly occurred in the shaft of the right thigh in a 21-year-old patient of Turkish descent with known homozygotic sickle cell anaemia. He also had marked scleral jaundice and anaemia (haemoglobin 9.1 g/dl). An X-ray film of the lower leg pointed to a bone infarct. Type of pain, partial pressure of oxygen in blood (70 mm Hg), concentration of lactate dehydrogenase and the bilirubin level (4,5 mg/dl) as signs of haemolysis, as well as the fall in haemoglobin, indicated a vascular occlusive crisis in sickle cell anaemia. TREATMENT AND COURSE: The symptoms regressed within 8 days of the patient receiving fluids, analgesics and oxygenation by nasal tube. A few weeks later he developed a fever, productive cough and severe pain in joints and abdomen. Blood p02 was 54 mm Hg. Pneumonia in the right lung base was the cause of this renewed life-threatening crisis, which was again associated with haemolysis. Klebsiella having been found in sputum he was treated with cefotaxim (1 g twice daily intravenously) and oxygen insufflation via nasal tube (7 l/min). His condition quickly improved. CONCLUSIONS: In patients with sickle cell anaemia it is important (1) to regard crises as potentially life-threatening conditions, (2) to detect and treat infections as possible causes early and (3) to provide sufficient oxygen insufflation quickly, especially in pulmonary infections.

Acute Disease↗
PubMed1995

Decreased production of TNF and IL-6 in whole blood of CLL patients.

Monocyte derived cytokines, tumor necrosis factor (TNF) and interleukin-6 (IL-6), were determined in cell free plasma after stimulation of heparinized whole blood from chronic lymphocytic leukemia (CLL) patients with lipopolysaccharide (LPS) at 1 microgram/ml for 6 hr. Compared to control donors (390 U/ml), CLL patients in average had eight-fold lower levels of TNF bioactivity (50 U/ml). The depressed levels were observed over a wide range of LPS concentrations (0.01 to 10 micrograms/ml). Furthermore, after stimulation with S. aureus bacteria, CLL samples gave three-fold lower levels, as well. TNF levels were not decreased because of defective bioactivity of TNF, since strongly reduced levels of TNF protein were also detected in an immunoassay. Finally, interleukin-6 levels after LPS stimulation were decreased threefold. Flow cytometry analysis with CD14 antibodies demonstrated comparable numbers of monocytes for control donors and CLL patients (698 +/- 802 and 427 +/- 267, respectively). This suggests that deficient cytokine production was not due to a reduction in monocyte number, but rather to a functional impairment. The deficiency in cytokine production observed after ex vivo stimulation of whole blood from CLL patients suggests that in vivo during bacterial infection, CLL patients will exhibit an inappropriate response as well.

Biological Assay↗