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M Micksche

Publications and source records attributed to M Micksche.

At least 19 recordsLinked to original sources
PubMed1999

G-CSF versus GM-CSF for stimulation of peripheral blood progenitor cells (PBPC) and leukocytes in healthy volunteers: comparison of efficacy and tolerability.

This study compared two recombinant human (rh) hematopoietic growth factors in healthy volunteers for stem cell stimulation. Granulocyte colony-stimulating factor (G-CSF, n=9) or granulocyte-macrophage colony-stimulating factor (GM-CSF, n=8) was given subcutaneously for 5 days (5 microg/kg/day). Controls (n=5) received no growth factor. Laboratory parameters and side effects were monitored for 8 days. Within 24 h, both cytokines led to a rapid increase of leukocytes, the majority of which were granulocytes. Compared with the controls (n=5), the increase on day 5 in the G-CSF/GM-CSF groups was 37-/10-fold (CD34+ cells), 5.2-/2.4-fold (leukocytes), 7.2-/3.0-fold (granulocytes), 7.4-/4.4-fold (monocytes), 1.7-/1.1-fold (lymphocytes), 9.8-/2.7-fold (basophils), 2.3-/9.6-fold (eosinophils), and 1.9-/1.6-fold (reticulocytes). The mobilization of myeloblasts, promyelocytes, myelocytes, and metamyelocytes coincided with the pronounced increase of CD34 + PBPC observed on day 4. Serum levels of uric acid (UA) and lactic dehydrogenase (LDH) increased under G-CSF, and platelets decreased after G-CSF discontinuation. Rash at the injection site occurred in 50% of the GM-CSF-treated volunteers. Seven volunteers in the GM-CSF group and six in the G-CSF cohort complained of flu-like symptoms, including musculoskeletal pain. We conclude that, in terms of tolerance and mobilization of CD34+ cells and leukocytes, G-CSF is superior to GM-CSF, but higher levels of UA and LDH and late decrease in platelets make monitoring of these parameters necessary.

Adult↗
PubMed1999

The role of macrophages in antitumor defense of patients with ovarian cancer.

Macrophages have diverse effects on tumor biology, including neovascularization, growth rate, and stroma formation. Tumor-associated macrophages (TAMs) represent a major subpopulation of the mononuclear leukocytes present in malignant ascites of ovarian cancer patients. TAMs appear to participate in the immunologic antitumor defense mechanism through cytotoxic activities, such as direct cellular cytotoxicity and the release of cytokines, and may represent key targets for a variety of therapeutic interventions.

Cytotoxicity, Immunologic↗
PubMed1999

The burden of cancer in Austria.

The aim of this study was to assess the overall progress against cancer in Austria by analysing changes in age-adjusted mortality rates from 1970 to 1996. For the years 1970 to 1996, age-adjusted rates for all malignant neoplasms and for selected sites were calculated for men and women, according to year, age and sex. The number of cancer deaths were obtained from the Austrian Central Statistical Office--age-adjusted mortality rates of all malignant neoplasms decreased in men between 1971 and 1996 by 13% (from 289.1 to 251.4 deaths per 100,000), and in women between 1970 and 1996 by 19.1% (from 276.6 to 223.7 deaths per 100,000). Among older people (> or = 55 years) the mortality decreased by 13% in men and by 17% in women; among younger people (< 55 years) by 12% and 30%, respectively. The decrease in total cancer mortality is promoted by three tumour sites (the leading causes of cancer deaths in 1970). In both sexes, the decrease of stomach cancer mortality had the major impact, followed by colorectal cancer in women and by lung cancer in men. The observed changes in mortality are primarily related to changing incidence and early detection, rather than improvements in treatment. Unfortunately, there is evidence that prevention is losing ground in Austria. The implementation of the well-established knowledge of cancer prevention and the strengthening of preventative research is urgently needed.

Adolescent↗
PubMed1998

A novel bioassay for P-glycoprotein functionality using cytochalasin D.

The functional contribution of both P-glycoprotein (P-gp) and the multidrug resistance-associated protein (MRP) to multidrug resistance (MDR) in tumor cells is commonly determined by drug cytotoxicity and/or accumulation/efflux tests. We report on a bioassay developed for the specific detection of functional P-gp levels and the efficacy of related chemosensitizers (CD-P-gp-assay). The assay is based on the flow cytometric measurement of changes in the > or = G2M cell cycle compartment which are due to the induction of polykaryons after exposure of proliferating cells to three defined cytochalasin D (CD) concentrations with and without verapamil. As demonstrated in 13 well-characterized MDR cell models (20 resistant sublines), there is a significant correlation between cytokinesis-blocking CD doses, as well as responsiveness to chemosensitizers and MDR1 gene expression (mRNA and P-gp) allowing discrimination between different levels of P-gp-MDR. CD-P-gp-assay specificity was assessed by testing 23 compounds: 19 known as potent inhibitors of P-gp-MDR, some of them, though to a lesser extent, also of MRP-MDR; 1 inhibiting MRP-but not P-gp-MDR; 3 inactive in both types of MDR. A modulation of CD activity was confined exclusively to both P-gp-expressing cell lines and P-gp chemosensitizers. CD cytoskeletal activity measured by FACS is a specific and sensitive tool with which to detect functional P-gp and related chemosensitizers.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1998

Stimulation of natural killer activity in peripheral blood lymphocytes of healthy donors and melanoma patients in vitro: synergism between interleukin (IL)-12 and IL-15 or IL-12 and IL-2.

Interleukin-2 (IL-2) and IL-12 modify the functional status of T- and natural killer (NK) cells by regulating proliferation, cytolytic activity, cytokine induction, and T-cell subset differentiation. These effects are exploited in immunotherapy of cancer patients with IL-2 or IL-12, which, however, is limited by potentially life-threatening side effects. IL-15 shares many of the biological activities of IL-2 and may therefore represent a therapeutic alternative. Here we have compared the ability of these interleukins to stimulate NK activity in peripheral blood lymphocytes (PBLs) isolated from healthy donors (n = 12) as well as from patients (n = 12) suffering from metastatic disease (melanoma). Target (K562) cell lysis was assessed by determining the release of 51Cr and lactate dehydrogenase (LDH) which gave equivalent results. The NK-resistant DAUDI cell line served as control target. Unstimulated NK activity was significantly lower in PBLs purified from melanoma patients. However, cytolytic activity was readily stimulated by preincubation of PBLs (18 h) with cytokines such that the maximum target cell lysis was comparable to that seen in PBL of healthy donors. Similarly, the potency of IL-2 (EC50 = 20.2+/-1.3 and 22.0+/-1.3 u/ml in healthy donors and patients, respectively), IL-12 (EC50 = 11.0+/-1.1 and 4.3+/-1.6 u/ml) and IL-15 (EC50 = 0.3+/-0.1 and 0.2+/-0.1 u/ml) was comparable. Importantly, if the preincubation was carried out with cytokine concentrations in the EC50 range, the effects of two cytokines (tested in all combinations) were additive. A synergism was evident in PBLs obtained both from healthy donors and melanoma patients if concentration-response curves for IL-12 were determined in the presence of increasing concentrations of IL-2 (enhanced efficacy) or IL-15 (enhanced efficacy and potency). Our observations suggest possible alternatives to the monotherapy with IL-2 (or IL-12) in cancer treatment. Provided that the present findings can be extrapolated to the situation in vivo, the combined administration of IL-12 and IL-15 may be as efficacious as the immunotherapy with IL-2; this approach ought to allow for a marked reduction in cytokine dose and thereby improve the therapeutic index.

Chromium↗
PubMed1998

Expression of the small heat shock protein HSP 27 in developing human skin.

The 27 kDa heat shock protein (HSP 27) is expressed in keratinocytes of the upper epidermal layers, and recent evidence suggests that this protein is involved in the regulation of epidermal differentiation. The expression of HSP 27 was investigated in developing human skin by immunohistochemistry utilizing a specific monoclonal antibody. We used formalin-fixed, paraffin-embedded tissue of abdominal skin obtained from 34 human fetuses ranging between 13 and 30 weeks estimated gestational age (EGA). We found that HSP 27 is not expressed in keratinocytes until week 14 EGA. At this stage staining is observed in the periderm and the upper intermediate cells but not in hair germs. During further development, HSP 27 expression correlates with increasing epidermal differentiation, i.e. shedding of the periderm and beginning of keratinization. HSP 27 expression is confined to the upper cell layers and sparse basal cells. In hair follicles, HSP 27 can be detected in the innermost cell layer of the outer root sheath and in keratinocytes of the bulge identical to what is observed in adult skin. The hair papilla, matrix cells and sebaceous glands are negative for HSP 27 and remain so during further development. In eccrine sweat glands of the 24th week EGA, HSP 27 is confined to the superficial cell layer of the sweat ducts. In the present report we demonstrate differentiation-related expression of HSP 27 in developing human skin. Further in vitro studies will address the molecular function of HSP 27 in epidermal differentiation and development.

Eccrine Glands↗
PubMed1997

Effects of multidrug resistance-related ATP-binding-cassette transporter proteins on the cytoskeletal activity of cytochalasins.

Cytochalasins are microfilament-active mould metabolites, widely utilized to study the involvement of the actin cytoskeleton in cellular processes as well as in genotoxicity and cell kinetic research. In this study we have investigated whether multidrug-resistance phenotypes, caused by overexpression of the ATP-binding-cassette transporter proteins P-glycoprotein (P-gp) or multidrug-resistance-associated protein (MRP), influence the microfilament-depolymerizing effect of cytochalasins. Using four well-characterized multidrug-resistance cell models, we have shown that both the microfilament-disrupting (phalloidine staining) and the cytotoxic (MTT-assay) activity of cytochalasins are reduced in parallel with increased P-gp expression and restorable by P-gp-modulating agents. This also applied to the cytochalasin D-mediated induction of polykaryons (microscopic evaluation) which arise as a consequence of impaired cytokinesis but unaffected karyokinesis. The reduced cellular activity of cytochalasins in P-gp-positive cell lines was correlated with decreased intracellular accumulation ([3H]cytochalasin B accumulation) which was also restorable by P-gp modulators. Moreover, the dose-dependent inhibition of P-gp photoaffinity labeling ([3H]-azidopine) suggested cytochalasins as P-gp-binding agents. In contrast, MRP overexpression had no effect on either cytochalasin microfilament activity or cytotoxicity. In conclusion, data indicate that the microfilament-destructive effects of cytochalasins are impaired due to a reduction of the intracellular cytochalasin accumulation by P-gp but not by MRP. Results are discussed with regard to P-gp as a resistance factor when cytochalasins are utilized to study microfilament dynamics, cell cycle kinetics or chromosomal damage. Moreover, the polykaryon-inducing activity of cytochalasin D is suggested as a specific indicator for a P-gp-mediated multidrug-resistance phenotype and the reversing potency of chemosensitizers.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1997

Expression of the multidrug resistance-associated protein (MRP) and chemoresistance of human non-small-cell lung cancer cells.

Human non-small-cell lung cancer (NSCLC) is considered to be a chemotherapy-refractory malignancy. The underlying mechanisms remain rather obscure. The multidrug resistance-associated protein (MRP), mediating a multidrug resistance (MDR) phenotype, has been reported to be overexpressed in several drug-selected lung cancer cell lines. A few previous studies have described intrinsic MRP expression in both NSCLC and normal lung tissues. However, the drug-transporting activity as well as the correlation with chemoresistance is unclear. Using 15 unselected cell lines, we show that MRP (mRNA and protein as detected by reverse transcriptase polymerase chain reaction and immunoblot) is frequently expressed intrinsically, with markedly varying intensity, in NSCLC. Two cell lines expressed high MRP levels, one comparable to the drug-selected controls (GLC4/ADR, HL-60/AR) without, however, amplification of the MRP gene (Southern hybridization). Using 3H-daunomycin (3H-DM) and calcein as MRP substrates and probenecid (PRO), genistein (GEN), benzbromarone (BB), N-ethylmaleimide (NEM) and verapamil (VP) as MRP modulators, drug accumulation studies revealed a transporting activity of MRP that correlated significantly with the gene expression data. Moreover, a significant correlation between MRP expression and chemoresistance against daunomycin (DM), doxorubicin (DOX), etoposide (VP-16) and vinblastine (VBL), but not cisplatin (CDDP) and bleomycin (Bleo) (MTT-based survival assay), was detected. Correlations mainly rested on the pronounced chemoresistance of 2 highly MRP-expressing cell lines and did not reach significance when these cell lines were excluded.

ATP-Binding Cassette Transporters↗
PubMed1997

Possible role of the multidrug resistance-associated protein (MRP) in chemoresistance of human melanoma cells.

Human malignant melanoma is characterised by unresponsiveness to conventional chemotherapy. Melanoma-derived cell lines are often markedly chemoresistant, suggesting that cellular mechanisms mediate the multidrug resistance (MDR) phenotype. The multidrug resistance-associated protein (MRP) is a drug transporter protein associated with resistance to a broad spectrum of lipophilic drugs. To investigate whether MRP is involved in intrinsic drug resistance of human melanoma, we analysed expression and functional activity of MRP as well as its impact on chemoresistance in 40 melanoma cell lines (35 established by us from primary and metastatic lesions and 5 obtained from international sources), as well as in one dysplastic naevus-derived cell line and in normal melanocytes. By reverse transcriptase-polymerase chain reaction various levels of MRP mRNA were detected in all melanoma cell lines, and by immunoblot the corresponding protein in a high percentage of them. Functional activity of MRP was assayed by analysing cellular accumulation of 3H-daunomycin (3H-DM) and calcein in response to MRP-modulators by beta-spectrometric and fluorescence-activated cell sorter analysis, respectively. Probenecid (PRO), N-ethylmaleimide (NEM) and benzbromarone (BB) moderately (< or = 1.43-fold) but significantly enhanced intracellular accumulation of MRP substrate probes corresponding to MRP expression. Moreover, the sensitivity of melanoma cell lines to daunomycin (DM) and doxorubicin (DOX), but not to vinblastine (VBL), etoposide (VP-16) and cisplatin (CDDP), analysed by an MTT-based survival assay, were inversely correlated with MRP-gene expression. Our results imply that MRP may be a component of the intrinsic chemoresistance phenotype characteristic of human malignant melanoma.

ATP-Binding Cassette Transporters↗
PubMed1996

Maximal androgen blockade in combination with methotrexate for treatment of metastatic prostate cancer.

Recently attention has been focused on the optimal timing of chemotherapy within the treatment regimen for patients with metastatic prostate cancer, i.e., hormonal manipulation, preferably maximal androgen blockage (MAB) consisting of chemical/surgical castration followed by treatment with antiandrogens. We have conducted a randomized prospective clinical trial, investigating the efficacy and toxicity of MAB (orchiectomy followed by flutamide therapy) alone as compared to MAB combined with methotrexate (MTX, 50 mg/m2/week) in 53 patients with newly diagnosed stage IV(M1) prostatic cancer (UICC TNM Classification 1987). The observed remission rates (complete + partial) of 42.3% in the MAB + MTX arm and 29.6% in the MAB arm did not differ significantly. The response rates (complete + partial + stable disease) of 73.1% and 66.7% for MAB + MTX and MAB respectively, also showed no significant difference. Neither progression-free survival (median 18/5 and 23.8 months for MAB + MTX and MAB, respectively) nor overall survival (median: 37.4 and 36.1) months in the MAB + MTX and MAB arm, respectively) could be improved by the addition of MTX to MAB Only the extent of metastatic pain reported by the patients was consistently less under MAB + MTX than under MAB alone (P<0.1). Both treatment regimens were well- tolerated with slightly more undesirable effects in the MAB + MTX arm. Our results do not provide evidence for the achievement of marked gains by combining chemotherapy with endocrine therapy in newly diagnosed patients with stage IV (M1) prostate cancer.

Aged↗
PubMed1996

Alveolar macrophages of patients with adult respiratory distress syndrome express high levels of heat shock protein 72 mRNA.

Adult respiratory distress syndrome (ARDS), a multifactorial disease with poor prognosis, is characterized by an accumulation of inflammatory cells within the airspaces of the lungs. There is evidence that alveolar macrophages (AM) are involved in the pathogenesis of this pulmonary disease. It has been demonstrated that AM synthesize heat shock proteins (HSPs) after exposure to certain stress factors. Increasing evidence suggests that HSPs could confer protection against oxidative injury, noxious molecules, and bacterial toxins. In stressed cells HSP 72 appears to be essential for survival during and after exposure to cellular injury. The aim of this study was to evaluate the magnitude of HSP 72 expression by human AM of patients with ARDS and correlate that with respiratory burst activity. Bronchoalveolar lavage was performed in six ARDS patients, 10 patients with high risk for developing ARDS, and two patients who underwent bronchoscopy for other reasons. Spontaneous ex vivo expression of HSP 72 in AM could be demonstrated by immunocytochemistry. Total RNA as well as poly(A)-rich mRNA were extracted from recovered AM and analyzed by Northern blot and slot blot using a human HSP 72-specific probe. Signals of slot blot were analyzed by densitometry and expressed as relative levels of HSP 72 mRNA of stressed (42 degrees C) HT 1080 control cells. Significantly (p < .001) higher levels of HSP 72 mRNA were measured in patients with ARDS (96.2 +/- 9.5 relative levels) in comparison to those not developing this syndrome (46.0 +/- 4.2). With regard to respiratory burst activity of AM in patients with ARDS, there was a negative correlation between HSP 72 expression and reactive oxygen species production. The AM of patients with ARDS with high relative levels of HSP 72 expression showed low respiratory burst activity. A predictive value for disease severity of high level of HSP 72 mRNA in AM in patients at risk for ARDS has to be evaluated by future studies. This demonstration of HSP 72 expression ex vivo suggests a protective role of HSP response against endo/exogenously generated stress factors in AM.

Adult↗
PubMed1996

Modification of growth and tumorigenicity in epidermal cell lines by DNA-mediated gene transfer of M(r) 27,000 heat shock protein (hsp27).

In the present communication, the role of the M(r) 27,000 human small heat shock protein (hsp27) in tumorigenicity was examined. Stable transfectants of a melanoma cell line (A375) and an epidermal squamous carcinoma cell line (A431), isolated by cotransfection of a hsp27 expression vector (pSG-2711) and a neomycin-resistant plasmid, were obtained. Clones expressing high levels of hsp27 were analyzed using immunohistochemistry and immunoblotting. Cells transfected with only the plasmid for neomycin were used as control cells. Growth analysis of transfectants in A375 and A431 tumor cells showed in vitro a lower proliferation rate than control clones derived from both lines. To investigate the correlation of hsp27 expression and tumorigenicity, transfectants of each cell type and control cells were injected into nude mice. A delay in tumor development was detected in animals inoculated with cells overexpressing hsp27. However, after this initial delay, tumors appeared in some of these animals and no difference could be observed in their growth dynamics compared to control tumors. When tumors transfected with the hsp27 construct were analyzed using immunohistochemistry and PCR, no evidence for hsp27 expression was obtained which implicates instability of the transduced foreign DNA when maintained under nonselective conditions. The present study shows that genetic manipulation of tumor cells may provide valuable information on the role of hsp27 in tumor growth.

Animals↗
PubMed1995

Prospective evaluation of interferon-alpha in treatment of chronic active Crohn's disease.

Several case reports suggested good effects of interferon-alpha in patients with Crohn's disease. In addition, a decreased production of interferon-alpha in Crohn's disease has been shown in vitro. Treatment with interferon-alpha may activate intestinal natural killer cells and down-regulate the overproduction of inflammatory cytokines like interleukin-6 in Crohn's disease. To evaluate the clinical efficacy of interferon-alpha, we treated 12 patients with a chronic active course of Crohn's disease with recombinant human interferon-alpha prospectively for 24 weeks. Prednisolone was continuously tapered and discontinued at week 12. The end point of the study was the prevention of worsening of clinical symptoms defined with the Crohn's disease activity index and was monitored by acute-phase proteins, interleukin-6 serum concentrations, and endoscopy. The biochemical activity of interferon-alpha was measured by 2',5'-oligo adenylate serum levels. The end point of the study was reached in four patients (33%). In these patients the final Crohn's disease activity index was above 150, which means that they did not achieve clinical remission. All other patients (66%) did not respond to interferon-alpha and had to be withdrawn prematurely. Interferon-alpha did not show any beneficial effect on interleukin-6 or acute-phase protein concentrations and on endoscopic activity. The 2',5'-oligo adenylate levels continuously increased during interferon therapy. Considerable side effects were noted. These results fail to demonstrate a therapeutic role of interferon-alpha in chronic active Crohn's disease.

Adenine Nucleotides↗
PubMed1995

Randomised study using IFN-alpha versus IFN-alpha plus coumarin and cimetidine for treatment of advanced renal cell cancer.

BACKGROUND: Treatment results in patients with metastatic renal cell cancer (RCC) are still extremely unsatisfactory. Rates of response to IFN-alpha monotherapy and/or IL-2 mono/combination therapy vary between 10% and 20%. Coumarin (Cum) together with cimetidine (Cim) has yielded objective responses in 20%-33% of patients with RCC, according to two recent phase II studies. PATIENTS AND METHODS: In the present study 148 patients with metastatic RCC were randomised to receive either IFN-alpha (5 MU 5 x weekly s.c.) + coumarin (100 mg/d p.o.) + cimetidine (3 x 400 mg/d p.o.), or IFN-alpha-monotherapy (5 MU 5 x weekly s.c.). RESULTS: Of the 148 patients in the study 137 were evaluable for response. No differences in remission rates (RR IFN-alpha + Cum + Cim 17.1% and IFN-alpha 20.8%) or survival times (median survival 9 months and 8 months, respectively) were found between these two treatment arms. CONCLUSIONS: This study confirms that INFN-alpha has antitumoral activity in RCC. Adding coumarin + cimetidine to IFN-alpha in the dose and regimen prescribed in this study did not increase response rates or survival.

Adult↗
PubMed1995

In vivo modulation of human neutrophil function by pentoxifylline in patients with septic syndrome.

The influence of pentoxifylline on human polymorphonuclear granulocyte (PMN) respiratory burst activity (RBA) was studied in 23 patients fulfilling the established criteria of sepsis and in 10 healthy donors. Pentoxifylline (PTX) was administered (5 mg/kg) by intravenous infusion in 13 septic patients over a period of 180 min. The control group consisted of 10 patients with septic syndrome who received an infusion of physiological saline. For determination of RBA, 10 mL of blood was drawn at respective time intervals before, during, and after treatment with PTX or a placebo. RBA measurements were performed using a chemiluminescence assay after stimulation of PMN with formyl-methionyl-leucyl-phenylalanine (FMLP), phorbol-myristate-acetate, and opsonized zymosan, respectively. RBA measurements of each patient were performed in replicate samples. CL was measured for 1 h at respective time intervals (1, 3, 5, 8, 10, 15 min etc). RBA of PMN of septic patients was compared with RBA of PMN of healthy donors and patients receiving PTX were compared with controls. Our results demonstrate that PMN of patients with sepsis had an increased oxidative response compared with healthy donors. We found that PTX administered intravenously was able to reduce this reactivity. RBA was significantly decreased during PTX infusion when PMN were stimulated with FMLP and phorbol-myristate-acetate, compared with the control group. No significant decrease was observed when PMN were stimulated with opsonized zymosan. These data suggest that PTX may be a valuable drug in septic state.

Adult↗
PubMed1994

Intrinsic MDR-1 gene and P-glycoprotein expression in human melanoma cell lines.

Metastatic malignant melanoma is considered a chemotherapy-refractory malignancy. A few previous studies have delivered contradictory results regarding the presence and functionality of P-glycoprotein (P-gp), a transmembranous protein associated with the classical multidrug resistance (cMDR), in malignant melanoma. Therefore we have investigated this issue on 33 cell lines established from primary and metastatic lesions of human malignant melanoma, comparing different cMDR detection methods. Immunocytochemically 33% of the cell lines stained positive for P-gp. The data correlated with those of a P-gp-radioimmunometric (antibody-binding) assay. When RT-PCR was used for MDR-1 mRNA determination, 76% of the melanoma cell lines scored positive. Slot-blot analysis was seen to be less sensitive than RT-PCR. Results from the functional P-gp assays, using daunomycin (DM) as MDR-substrate, showed no influence of P-gp expression on drug accumulation and cytotoxicity. However, the cMDR-modifier verapamil (VP) significantly increased both parameters in those melanoma cells with the highest P-gp levels. We conclude that cMDR is apparently not the decisive but probably a complementary protective mechanism against toxic agents in malignant melanoma.

ATP Binding Cassette Transporter, Subfamily B, Mem↗