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G Gastl

Publications and source records attributed to G Gastl.

At least 55 records · Page 3Linked to original sources
PubMed1999

Vascular endothelial growth factor in the sera and effusions of patients with malignant and nonmalignant disease.

BACKGROUND: Clinical data clearly indicate a correlation between tumor neovascularization, aggressiveness of tumor growth, and metastatic spread. One of the key factors capable of stimulating tumor angiogenesis is vascular endothelial growth factor (VEGF). Using an immunoassay for VEGF, we assessed the levels of soluble VEGF in the sera and effusions of patients with malignant and nonmalignant disease as well as in the sera of healthy controls. METHODS: Using a sandwich enzyme-linked immunoadsorbent assay, the concentration of VEGF was measured in serum specimens (n=445) and effusions (n=56) collected from a total of 212 patients with various types of cancer, 88 patients with nonmalignant disease, and 145 healthy individuals. RESULTS: Low and rather stable levels of VEGF were detected in the serum of healthy individuals (median, 294 pg/mL; range, 30-1752 pg/mL; 95th percentile, 883 pg/mL). Compared with healthy individuals, serum levels in patients with acute infections were elevated (P=0.03), whereas patients with chronic cirrhosis had lower serum VEGF levels. Among patients with various types of neoplasia, VEGF serum levels in patients with ovarian or gastrointestinal carcinoma were significantly higher than in healthy individuals. Moreover, VEGF concentrations in sera from patients with metastatic disease were higher than in sera from patients with localized tumors. Maximum serum concentrations of VEGF (median, 1022 pg/mL; range, 349-7821 pg/mL) were found in patients with metastatic ovarian carcinoma. Median VEGF levels (and ranges) in malignant effusions were up to 10-fold higher than in matched serum samples: 5528 pg/mL (468-49269 pg/mL) in ovarian carcinoma, 885 pg/mL (77-14,337 pg/mL) in breast carcinoma, and 813 pg/mL (372-18,331 pg/mL) in gastrointestinal carcinoma. In contrast, ascitic fluid from patients with cirrhosis contained only 303 pg/mL (median, range 116-676 pg/mL) of VEGF, corresponding to the low serum levels in this patient group. CONCLUSIONS: Depending on the tumor type, elevated levels of VEGF are detectable in the serum of only 0-20% of patients with localized cancer but in 11-65% of patients with metastatic cancer. Of cytology-proven malignant ascites or peritoneal exudates from various malignancies, 46-96% show VEGF levels above the upper limit (95th percentile, 676 pg/mL) of nonmalignant ascites. Maximum VEGF concentrations in malignant effusions indicate abundant local release of VEGF within the pleural or peritoneal cavity. These results suggest that VEGF might play an important role in tumor progression and the formation of malignant effusions. Further studies are warranted to determine the clinical value of soluble VEGF as a tumor marker, a prognostic factor, and a surrogate indicator of tumor angiogenesis.

Adult↗
PubMed1999

Aspergillus osteoarthritis in acute lymphoblastic leukemia.

We report an unusual case of arthritis of the right wrist due to Aspergillus fumigatus without evidence for a generalized infection, following chemotherapy for acute lymphoblastic leukemia. The diagnosis was made by surgical biopsy. Amphotericin-B (Am-B) was not tolerated by the patient. Liposomal preparations of Am-B penetrate poorly into bone and cartilage. Therefore, oral itraconazole was given; the arthritis improved and chemotherapy was continued without infectious complications. Two weeks after complete hematopoietic recovery, an intracranial hemorrhage from a mycotic aneurysm of a brain vessel occurred, although the patient was still receiving itraconazole. We emphasize the importance of prompt and thorough efforts to identify the causative agent in immunocompromised patients with a joint infection. Itraconazole is effective in Aspergillus osteoarthritis but, due to its poor penetration into the brain, the combination with a liposomal formulation of Am-B is recommended.

Antifungal Agents↗
PubMed1998

Interferon-alpha for the treatment of elderly patients with chronic myeloid leukaemia.

The present retrospective analysis is based on data of 213 patients with chronic myeloid leukaemia (CML). They were treated with interferon (IFN)alpha-2C (Berofor) at daily doses of 3.5 MU subcutaneously (s.c.), alone or in combination with low-dose ara-C or hydroxyurea, according to four consecutive studies of the Austrian CML Study Group. Comparisons were made between 41 patients aged > or = 60 years and 172 younger patients. The elderly patients (median: 64 years; range: 60-73) showed similar pretreatment characteristics compared with the younger group, but included a higher percentage of Sokal Stage three (51 vs 20%). Median observation periods were similar (38 vs 39 months), whereas the duration of IFNalpha treatment was shorter in the elderly group (median 57 vs 42 weeks). The rate of overall haematological responses (73 vs 78%) and complete haematological response (44 vs 54%), was similar in both cohorts. Differences seen in partial (5 vs 12%) and complete cytogenetic response (10 vs 13%), were not statistically significant, but a tendency in favour of the younger cohort had to be noted. Summing up, in elderly patients acceptable rates of haematological and cytogentic response can be expected after treatment with IFNalpha alone or in combination with LD ara-C or HU.

Adolescent↗
PubMed1998

Differential activity of P-glycoprotein in normal blood lymphocyte subsets.

To better understand the phenomenon of P-glycoprotein (P-170) expression we investigated lymphocyte subpopulations for P-170 function in healthy volunteers. Studies were based on three-colour flow cytometry including the fluorescent probe rhodamine 123 (Rh123), which is transported by P-170. Marked Rh123 efflux was detected in CD8+ T lymphocytes with CD8+/CD45RA+ T cells (naive cells) showing significantly higher P-170 activity as compared with CD8+/CD45RA- cells (P<0.04). Vice versa, CD8+/CD45RO+ T cells (memory cells) demonstrated less P-170 activity than CD8+/CD45RO- cells (P<0.04). P-170 function was less prominent in CD4+ T cells, however, Rh123 efflux was higher in the CD4+/CD45RA+ and CD4+/CD45RO- subpopulations (P<0.025) corresponding to the CD8+ results. Dye efflux differed significantly between activated and non-activated CD8+ and CD4+ as well as CD8+/CD11b+ and CD8+/CD11b- T lymphocytes. Since CD16+ natural killer cells (NK) expressed the highest level of P-170, the NK cytotoxicity against 51Cr-labelled K562 target cells was assayed in the presence or absence of P-170 inhibitors. NK related cytotoxicity was significantly reduced in the presence of R-verapamil and dexnigaldipine-HCP in a dose-dependent manner. The differential expression of P-170 activity in naive and memory T cells together with the reduced NK related cytotoxicity in the presence of MDR-modulators suggest a physiological role of P-170 in immunological functions of these lymphocyte subsets. Consequently, the addition of MDR modulators to conventional chemotherapy as a strategy to overcome drug resistance should consider possible adverse immunosuppressive effects.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1998

Vascular endothelial growth factor in serum and in the follicular fluid of patients undergoing hormonal stimulation for in-vitro fertilization.

A cross-sectional study regarding endocrine and cytokine parameters in human follicular fluid (FF) as compared to serum values following hormonal stimulation for in-vitro fertilization was conducted. The patients (n = 32) were treated sequentially with the luteinizing hormone-releasing hormone (LHRH) agonist buserelin followed by a combination of buserelin plus highly purified follicle stimulating hormone and finally human chorionic gonadotrophin, in order to induce ovulation. The FF content of pro-inflammatory (IL-1, IL-6), and anti-inflammatory (IL-1ra, IL-10) cytokines, of the immune response-related soluble interleukin-2 receptor (sIL-2R), as well as the mitogens vascular endothelial growth factor (VEGF) and basic fibroblastic growth factor (bFGF) were determined. Routine evaluation included peripheral blood cell counts, morphological data of the ovary and ova, ovarian steroids, prolactin concentrations and thyroid function parameters [free thyroxine (fT4), thyroglobulin]. The concentrations of IL-6, IL1-ra, sIL-2R, VEGF and bFGF in the FF compartment were higher than in serum in the majority of cases. Regression analysis showed a significant association between the serum and FF concentrations of fT4 (P = 0.04; y = 0.37 + 0.34x) and IL-6 (P = 0.002; y = 0.78 + 0.5x). Multiple regression analysis revealed that progesterone played a role in determining VEGF concentrations in the FF (P = 0.07; y = 0.37 + 0.86x). Thyroglobulin concentrations within the FF were extremely low, whereas fT4 concentrations in the FF were similar to those in serum. Patients with a previously diagnosed hypothyroidism tended to have lower serum oestradiol and higher serum progesterone when compared to euthyroids. We conclude that the human FF represents a functional compartment that integrates endocrine, immunological, and mitogenic signalling that is unique for each ovarian follicle. The close association between progesterone and VEGF within the FF suggests a close association of this mitogen to gonadotrophin stimulation, confirming the ovary as a production site of VEGF.

Adult↗
PubMed1997

Paclitaxel- and docetaxel-dependent activation of CA-125 expression in human ovarian carcinoma cells.

Taxanes represent a new class of antineoplastic agents that are being evaluated in several malignant tumors; they have been shown to induce a high remission rate and to prolong survival in ovarian cancer patients. However, CA-125 has been suggested to be an unreliable marker for monitoring response to paclitaxel therapy. Therefore, we were interested in whether taxanes may directly modulate CA-125 expression. Human ovarian carcinoma cell lines OVCAR-3, HOC-7, SKOV-6, 2780, 2774, and HTB-77 were treated with paclitaxel or docetaxel. Secreted, surface-associated, and cytosolic CA-125 were estimated by means of a sandwich solid-phase RIA or by immuno-flow cytometry. In addition to in vitro antiproliferative activity, paclitaxel and docetaxel augmented the expression of the tumor marker CA-125 in the three ovarian carcinoma cell lines, OVCAR-3, HOC-7, and SKOV-6, constitutively expressing this tumor marker. The three CA-125-negative cell lines, 2780, 2774, and HTB-77, did not respond to taxane treatment by expressing this tumor marker, although their proliferation was markedly inhibited. The taxane-mediated induction of CA-125 was found to be dependent on intact protein and RNA biosynthesis. However, CA-125 concentration was increased in the supernatant medium only and not on cell surface or cytosol. Our results demonstrate an in vitro activation of ovarian carcinoma cells in terms of CA-125 secretion by taxanes. This may explain the CA-125 fluctuations observed in vivo under paclitaxel treatment and may indicate that CA-125 is not a reliable tumor marker during taxane chemotherapy.

Antineoplastic Agents, Phytogenic↗
PubMed1997

Bacillus Calmette-Guérin mycobacteria stimulate human blood dendritic cells.

Bacillus Calmette-Guérin (BCG) mycobacteria have been used as adjuvant in the active immunotherapy of various human cancers. In addition, dendritic cells, which are the most potent antigen-presenting cells, have been shown to be capable of initiating anti-tumor immune responses. Here we investigated the effects of BCG on dendritic cells cultured from human blood. Addition of BCG resulted in rapid homotypic adhesion of dendritic cells. Moreover, BCG concentrations ranging from 10(4) to 10(6) bacteria/ml enhanced expression of the dendritic-cell-maturation antigen CD83 and of the T-cell co-stimulator CD86 (B7-2) in a dose-dependent manner. Concomitant with the increase of CD83 and CD86 expression, the cells lost the ability to capture soluble antigens, as determined by the exclusion of fluoresceinated Dextran molecules. Strikingly, the same dosages of BCG-bacteria stimulated TNF-alpha-gene transcription and TNF-alpha-protein release from dendritic cells in a dose-dependent fashion. BCG infection of dendritic cells in the presence of a neutralizing antibody directed against TNF-alpha inhibited CD83 expression by more than 50% indicating that the BCG-induced maturation of dendritic cells was at least partially mediated by dendritic-cell-derived TNF-alpha. The finding that BCG activates the most potent antigen-presenting cells reveals a plausible immunological mechanism of the occasionally observed anti-tumor activity of BCG.

Antibodies, Monoclonal↗
PubMed1997

Local expression of cytokines in rat bladder carcinoma tissue after intravesical treatment with Nocardia rubra cell wall skeleton and bacille-Calmette-Guerin.

This study aimed to investigate local immunotherapy with Nocardia rubra cell wall skeleton (N-CWS) and bacille-Calmette-Guerin (BCG) in chemically induced rat bladder carcinoma. After being fed with 0.025% N-butyl-N-(4-hydroxybutyl) nitrosamine for 26 weeks, female Wistar rats were treated once a week by intravesical instillation of 100 microg N-CWS or 5 x 10(6) Colony-Forming Units (CFU) BCG. Tissue specimens were obtained 4 h after the ninth instillation and analyzed by reverse transcription polymerase chain reaction (RT-PCR) for mRNA expression of rat cytokines. The analysis showed high expression of interleukin (IL)-1 alpha, tumor necrosis factor (TNF)-alpha, IL-2, and interferon (IFN)-tau in BCG (7/7, 7/7, 7/7, 5/7) and N-CWS (9/9, 9/9, 8/9, 8/9) treated tumors in comparison to low expression in controls (3/9, 0/9, 3/9, 3/9). Interestingly, intravesical instillation of N-CWS tended to be less effective at preventing local invasion of the tumors. It is speculated that this difference may result from a more strongly induced expression of T-helper cell-derived lymphokines (IL-2, IFN-tau) by BCG.

Actins↗
PubMed1997

In vitro generation of CD83+ human blood dendritic cells for active tumor immunotherapy.

There is increasing clinical interest in dendritic cells that are capable of initiating antitumor immune responses. Dendritic cells cultured from human blood mononuclear cells using granulocyte/macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4) are competent for antigen uptake but express relatively low levels of costimulatory molecules and thus correspond to immature resident tissue dendritic cells. In this study we took advantage of the new dendritic cell-specific marker CD83, which is expressed by mature dendritic cells, to delineate the maturation of cultured human blood dendritic cells. Although dendritic cells cultured with GM-CSF and IL-4 contained transcripts for CD83 as determined by reverse transcription PCR, CD83 protein was barely detectable by flow cytometry, confirming that dendritic cells obtained with this system are immature. However, treatment of dendritic cells with tumor necrosis factor-alpha (TNF-alpha) significantly increased the levels of CD83 transcripts and induced CD83 protein expression in dendritic cells. In contrast to the initiation of dendritic cell culture, which was facilitated by high cell density (5 x 10(6) cells/mL), differentiation into CD83+ dendritic cells required a low cell concentration (0.5 x 10(6) cells/mL). At higher cell density (1 x 10(6) cells/mL), CD83 expression was suppressed and was almost completely prevented at 2 x 10(6) cells/mL. Induction of CD83 expression was accompanied by a strong upregulation of the costimulator B7-2 (CD86) on dendritic cells. While untreated CD83(-) dendritic cells efficiently internalized fluoresceinated Dextran, TNF-alpha treated CD83+ dendritic cells excluded these molecules, confirming that maturation of dendritic cells was associated with the silencing of the antigen-capturing machinery. Morphologically, CD83+ dendritic cells presented with pronounced cytoplasmic projections (veils) characteristic of mature dendritic cells. In summary, we show that cell density critically regulates dendritic cell development. Knowledge of the appropriate conditions for dendritic cell generation and maturation will be important in clinical immunotherapy settings.

Antigens, CD↗
PubMed1997

[High dose therapy with transplantation of autologous peripheral hematopoietic stem cells. II. Indications and clinical results].

Transplant studies in a variety of malignant diseases suggest that dose intensification with peripheral stem cell support can be safely applied to a wide range of patients. The clinical results are comparable to that after autologous bone marrow transplantation by achieving long lasting remissions, even in advanced disease. Clinical studies evaluating this therapeutic modality in leukemias, Hodgkin's-and non-Hodgkin's lymphoma, myeloma, and in chemotherapy-sensitive solid tumors are in progress. The clinical results compared to conventional chemotherapy are summarized in Table 1. Several approaches are targeted at improved elimination of malignant cells: 1) incorporation of new drugs into preparative conditioning regimens, 2) tandem or multiple cycles of high-dose chemotherapy followed by stem cell rescue, 3) post-transplant immunomodulation aimed at inducing an antitumor effect, and 4) purging techniques to eliminate contaminating tumor cells from the transplant. Improvements in stem cell technology and supportive care will decrease the mortality of the procedure and leed to a substancial cost reduction.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

[High dose therapy with transplantation of autologous peripheral hematopoietic stem cells. I. Basic principles and clinical development].

High-dose therapy with peripheral stem cell rescue is increasingly being used as a salvage or consolidation therapy for patients with malignant disease. The accelerated hemopoietic recovery and the collection of peripheral stem cells in an outpatient setting are the main advantages. Recent findings on tumor cell contamination of autografts stimulated the development of techniques for tumor cell reduction, based on negative selection (purging) of tumor cells or positive selection of CD34+ progenitor cells. Purging and CD34 selection could probably result in increased cure rates. CD34 selection is also imperative for the successful expansion of progenitor cells in vitro. Using various mixtures of cytokines, different cell lineages may be preferentially expanded. A further area of interest is gene transfer into hematopoietic cells, where a purified cell population is a prerequisite for success. Future directions are the increase of cure rates by sequential administration of chemotherapeutic drugs at their maximum tolerated doses, the evaluation of new antineoplastic drugs and improved supportive care.

Antigens, CD34↗
PubMed1996

Current and future strategies to block tumor angiogenesis, invasion, and metastasis.

Progression of malignancy involves a series of sequential steps that ultimately lead to cancer-cell dissemination. In addition to the loss of growth control, an imbalanced regulation of motility and proteolysis is a prerequisite for invasion and metastasis. These factors are also necessary for angiogenesis-an integral process occurring at both the primary and the metastatic sites. Investigators have elucidated in detail many of the molecular mechanisms involved in the sequential steps of the metastatic cascade and have thereby provided new targets for therapeutic intervention. For each step, different model systems have been developed and various strategies for antimetastatic therapy have been tested in vitro as well as in murine systems. Difficulties in translating results obtained in preclinical models into the clinical setting have become apparent and have not been unexpected in light of the sometimes highly artificial interaction in the experimental setting. Nevertheless, continued development of model systems and further research into the genetic control of malignancy should lead to the identification of common signal-transduction pathways. Interference at such sites promises to be particularly effective in inhibiting proliferation and metastasis.

Animals↗
PubMed1996

Interferon alpha-2c therapy of patients with chronic myelogenous leukemia: long-term results of a multicenter phase-II study. Austrian Biological Response Modifier (BRM) Study Group.

In a prospective multicenter phase-II trial 80 patients with Philadelphia (Ph)-positive chronic myelogenous leukemia (CML) were treated with recombinant interferon (IFN) alpha-2c, administered subcutaneously at an absolute dose of 3.5 megaunits (MU)/day. Complete hematological remission was achieved in 29 (39%) and partial hematological remission in 26 (35%) of the 74 patients evaluable for response. Major cytogenetic responses were observed in ten (13%) and minor cytogenetic responses in 11 patients (15%). Median duration of cytogenetic response was 33 months (range, 2-90); relapses were seen in all of the 11 patients with minor and in three of the ten patients with major cytogenetic responses. Median survival estimates for pretreated (n = 19) and untreated (n = 58) patients were 51 months (95% confidence interval [CI], 30-72) and 77 months (95% CI, 43-111), and the survival probabilities at 5 years were 45% and 54% for the two groups, respectively. Hematological response after 3 months of treatment demonstrated a clear-cut discriminative capacity with 5-year survival probabilities of 100%, 67% and 24% for patients achieving CHR (n = 6), PHR (n = 34), and less than PHR (n = 35), respectively. Landmark analysis at 12, 18, and 24 months after start of IFN therapy and an analysis treating time to cytogenetic response as a time-dependent covariate showed that cytogenetic response was associated with longer survival. The impact of a low-dose IFN regimen on survival in CML patients is unclear and requires further clarification by randomized clinical trials. Early hematological and cytogenetic response to IFN-alpha treatment identifies patients with a favorable long-term prognosis.

Adolescent↗
PubMed1996

Major histocompatibility complex class I and class II expression in renal cell carcinoma and modulation by interferon gamma.

PURPOSE: To determine the expression of MHC class I and II in human renal cancer. MATERIALS AND METHODS: We analyzed tissue sections from 22 primary and 28 metastatic renal cell carcinomas (RCC), as well as 31 established RCC cell lines. Tissue specimens from normal kidney and cell cultures of normal kidney epithelium were also studied. In addition, MHC antigen expression on RCC cell lines was assessed both before and after incubation with human recombinant interferon gamma (IFN-gamma). Antigen expression was determined by mixed hemadsorption, indirect immunofluorescence, fluorescence activated cell sorting (FACS) or immunoperoxidase staining using the monoclonal antibodies (mAbs) W6/32 (anti-MHC class I), mAbs NAMB-1 and BBM.1 (anti-beta-2 microglobulin), and mAbs L243 and 13-17 (anti-MHC class II) antibodies. Soluble beta-2 microglobulin in conditioned medium was measured by ELISA. RESULTS: Normal renal epithelial cells, both in vivo and in vitro, showed low level expression of class I antigens. Immunohistochemical staining for MHC class II was limited to some proximal tubular cells, while cultured renal tubular cells were uniformly class II negative. The tumor cell populations in all 22 primary and in 26 of 28 (93%) metastatic RC specimens consisted predominantly of class I positive cells. Half of the samples from primary and metastatic tumors were class II negative. Incubation of RCC cell lines with IFN-gamma enhanced the expression of MHC class I, beta-2 microglobulin and class II. The upregulation of MHC expression was time and dose dependent and associated with increased release of soluble beta-2 microglobulin. CONCLUSIONS: (i) Like normal kidney, virtually all primary human renal cell carcinomas express MHC class I antigens and retain this phenotype even during tumor progression and metastasis; (ii) class II expression on normal and RCC cells appears more limited but occurs frequently in both primary and metastatic lesions; and (iii) in most continuous RCC cell lines expression of MHC class I and II can effectively be stimulated by IFN-gamma. Since expression of MHC molecules might determine the immunogenicity of human RCC, its constitutive expression and augmentation could play an important role for the immunotherapy and prognosis of human renal cancer.

Carcinoma, Renal Cell↗
PubMed1995

Symposium on health economics in oncology. Freiburg, Germany, June 1995.

Dr. E. Enghofer (Wien, Austria) summarized the content of the presentations and discussions of the symposium in his concluding remarks. 1. The organizers should be congradulated on their initiative in bringing together at the symposium experts from different disciplines, i.e., medicine, ethics, health economics, jurisprudence, the pharmaceutical industry and, last but not least, cost providers. 2. Health economics as an issue in health care has been around for quite some while. One example can be found in the German Drug Guidelines dating back to 1990, where the following terms have already been defined: therapeutic benefit, medical needs, and achieving therapeutic goals. 3. Health economics serves as a "support function" in the medical decision-making process. It has as yet no decisive role in the application to license a drug nor in questions concerning a physician's liability. Health economics as a discipline, however, was a reminder of, and served as a catalytic function for: a) The differentiation between the benefit of a medical intervention and its pure effectiveness. b) The definition of medical standards as a means to compare the quality of health care between different institutions, to uncover quality deficits and to develop strategies for the optimization of medical quality (quality management). Routine deviation from these standards is unethical. The German Cancer Society has taken on the task of defining such standards in cancer care. c) The difference between rationalising and rationing health care. The spending of the current health-care budget needs to be screened for unnecessary and/or inappropriate diagnostic procedures and treatment modalities as well as for "below-standard" care. The money that can be saved here can then be shifted towards financing "state of the art" medicine or can be used in the decision to substitute certain procedures. 4. The a priori definition of the desired outcome of a medical intervention is of paramount importance for the evaluation of the actual treatment result. Economical evaluations are easier when cure rather than palliation is the aim of a particular treatment and when alternative therapies do exist such that cost comparisons are possible. In any case, therapeutic interventions need to be adapted to the desired treatment goal; only then can the question be answered whether or not the means (cost) are (is) justified. 5. Outcome studies need to take into account every relevant medical aspect (i.e. disease management studies), and they should be accompanied by evaluation studies. The latter must also include unselected patients in daily practice.(ABSTRACT TRUNCATED AT 400 WORDS)

Antineoplastic Agents↗