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  • 1995-1999  (1.177)
  • 1990-1994
  • 1905-1909  (676)
  • 1999  (1.177)
  • 1907  (676)
  • General Chemistry  (1.426)
  • Analytical Chemistry and Spectroscopy  (132)
  • apoptosis  (112)
  • chemotherapy  (86)
  • crystal structure  (79)
  • Biochemistry
  • Genetics
  • Nuclear reactions
  • Physical Chemistry
  • Polymer and Materials Science
Materialart
Erscheinungszeitraum
  • 1995-1999  (1.177)
  • 1990-1994
  • 1905-1909  (676)
Jahr
Schlagwörter
  • 101
    ISSN: 1436-2813
    Schlagwort(e): Key Words: lung cancer ; culture ; heterogeneity ; drug screening assay ; subline ; chemotherapy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Materialart: Digitale Medien
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  • 102
    ISSN: 1436-2813
    Schlagwort(e): Key Words: nitric oxide ; DNA damage ; apoptosis ; tumor necrosis factor-α ; mitochondrial respiration
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: S -nitroso-N-acetylpenicillamine protected cul-tured L929 cells from apoptosis induced by tumor necrosis factor-α (TNF-α) plus actinomycin D, as determined by the detection of DNA fragmentation and morphological changes. NO also prevented an enhancement of the production of reactive oxygen intermediates by TNF-α plus actinomycin D, as assessed by the oxidation of dihydrorhodamine 123 and hydroethidine. Because the inhibition of mitochondrial respiration by rotenone or antimycin A suppressed the increased oxidation of both dihydrorhodamine 123 and hydroethidine, it was suggested that TNF-α accelerated the leakage of reactive oxygen intermediates from the mitochondrial electron transport system. Polarography showed that NO reversibly inhibited mitochondrial respiration at either complexes I–III, II–III, or IV, thus suggesting the inhibition of cytochrome oxidase. Taken together, these findings indicate that the decreased mitochondrial formation of reactive oxygen intermediates in the presence of NO might have a protective effect against TNF-α plus actinomycin D-induced apoptosis.
    Materialart: Digitale Medien
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  • 103
    ISSN: 1436-2813
    Schlagwort(e): angiogenesis ; p53 ; apoptosis ; lung adenocarcinoma ; hematogenous metastasis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The purpose of this study was to clarify which factors are important as predictors not only of patient survival but also of hematogenic metastasis in 15 patients with stage I lung adenocarcinoma who underwent curative operation. The relationship between tumor angiogenesis, apoptosis, and p53 oncogene was also studied. A total of 15 patients were divided into two groups: surviving group (n=7) and nonsurviving (metastasis) group (n=8). We studied the medical charts, operative records, pathologic reports, and tumor specimens taken at surgical resection. We measured the apoptotic index using the ApopTag kit and the intratumoral microvessel count using an anti-CD34 monoclonal antibody. In addition, immunohistochemical staining for the expression of p53 was conducted simultaneously. The clinicopathological characteristics, including age, sex, tumor size (pT), and histological differentiation, were not significantly different between the surviving and the nonsurviving group. The microvessel count was significantly higher in nonsurviving group than in the surviving group. The apoptotic index and the expression of p53 was not significantly different between the two groups. An inverse correlation between the apoptotic index and microvessel count, and a positive correlation between the expression of p53 and microvessel count, were observed. Angiogenesis may be an important prognostic factor in patients with stage I lung adenocarcinoma.
    Materialart: Digitale Medien
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  • 104
    ISSN: 1436-2813
    Schlagwort(e): Key Words: angiogenesis ; p53 ; apoptosis ; lung adenocarcinoma ; hematogenous metastasis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: n = 7) and nonsurviving (metastasis) group (n = 8). We studied the medical charts, operative records, pathologic reports, and tumor specimens taken at surgical resection. We measured the apoptotic index using the ApopTag kit and the intratumoral microvessel count using an anti-CD34 monoclonal antibody. In addition, immunohistochemical staining for the expression of p53 was conducted simultaneously. The clinicopathological characteristics, including age, sex, tumor size (pT), and histological differentiation, were not significantly different between the surviving and the nonsurviving group. The microvessel count was significantly higher in nonsurviving group than in the surviving group. The apoptotic index and the expression of p53 was not significantly different between the two groups. An inverse correlation between the apoptotic index and microvessel count, and a positive correlation between the expression of p53 and microvessel count, were observed. Angiogenesis may be an important prognostic factor in patients with stage I lung adenocarcinoma.
    Materialart: Digitale Medien
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  • 105
    ISSN: 1432-0533
    Schlagwort(e): Key words Frontotemporal dementia ; Genetics ; Progressive supranuclear palsy ; Tauopathy ; Exon ; amplifcation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Recently intronic and exonic mutations in the Tau gene have been found to be associated with familial neurodegenerative syndromes characterized not only by a predominantly frontotemporal dementia but also by the presence of neurological signs consistent with the dysfunction of multiple subcortical neuronal circuitries. Among families, the symptomatology appears to vary in quality and severity in relation to the specific Tau gene mutation and often may include parkinsonism, supranuclear palsies, and/or myoclonus, in addition to dementia. We carried out molecular genetic and neuropathological studies on two patients from a French family presenting, early in their fifth decade, a cognitive impairment and supranuclear palsy followed by an akinetic rigid syndrome and dementia. The proband died severely demented 7 years after the onset of the symptoms; currently, his brother is still alive although his disease is progressing. In both patients, we found a Tau gene mutation in exon 10 at codon 279, resulting in an asparagine to lysine substitution (N279K). Neuropathologically, widespread neuronal and glial tau accumulation in the cortex, basal ganglia, brain stem nuclei as well as in the white matter were the hallmark of the disease. These deposits were shown by immunohistochemistry and immunoelectron microscopy, using a battery of antibodies to phosphorylation-dependent and phosphorylation-independent epitopes present in multiple tau regions. In the neocortex, tau-immunopositive glial cells were more numerous than immunopositive neurons; the deeper cortical layers as well as the white matter adjacent to the cortex contained the largest amount of immunolabeled glial cells. In contrast, some brain stem nuclei contained more neurons with tau deposits than immunolabeled glial cells. The correlation of clinical, neuropathological and molecular genetic findings emphasize the phenotypic heterogeneitiy of diseases caused by Tau gene mutations. Furthermore, to test the effect of the N279K mutation and compare it with the effect of the P301L exon 10 mutation on alternative splicing of Tau exon 10, we used an exon amplification assay. Our results suggest that the N279K mutation affects splicing similar to the intronic mutations, allowing exon 10 to be incorporated more frequently in the Tau transcript.
    Materialart: Digitale Medien
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  • 106
    Digitale Medien
    Digitale Medien
    Springer
    Annals of hematology 78 (1999), S. 485-494 
    ISSN: 1432-0584
    Schlagwort(e): Key words Mantle cell lymphoma ; Classification ; Pathology ; Prognosis ; Immunology ; Genetics ; Antineoplastic agents ; Combined ; Therapeutic use ; Radiotherapy ; Hematopoietic stem cell transplantation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Materialart: Digitale Medien
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  • 107
    ISSN: 1432-0584
    Schlagwort(e): Key words Acute leukemia ; Genetics ; Sex ; ABO Blood group
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Acute leukemia is more common in males at almost every age, and this fact remains unexplained. A study was carried out in northeast peninsular Malaysia, where the population is predominantly Malay, to examine whether there was a difference in ABO blood group distribution between males and females with acute leukemia (AL). The ABO blood groups of 109 male and 79 female patients with AL (98 ALL, 90 AML) were compared with those of 1019 controls. In the control population, 39.7% were group O. Among males with AL, 39.4% were group O, whereas among females with AL, the proportion was 24.1% (p=0.03). The same trend to a lower proportion of group O among females was seen if the group was divided into adult/pediatric or lymphoblastic/myeloblastic groups, though these differences were not statistically significant. If these findings can be confirmed, they suggest the presence of a "sex-responsive" gene near to the ABO gene locus on chromosome 9, which relatively protects group O women against AL, at least in our population. The existence of such a gene might also partly explain why acute leukemia, and possibly other childhood cancers, are more common in males.
    Materialart: Digitale Medien
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  • 108
    Digitale Medien
    Digitale Medien
    Springer
    Diabetologia 42 (1999), S. 711-718 
    ISSN: 1432-0428
    Schlagwort(e): Keywords Malnutrition ; ageing ; beta-cell mass ; apoptosis ; glucose tolerance.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Aims/hypothesis. In a recently developed rat model, maternal food restriction from day 15 of pregnancy until weaning induced low birth weight and a 70 % reduction of beta-cell mass in the offspring at day 21 after birth. Subsequent renutrition from weaning was insufficient to fully restore beta-cell mass in young adult rats. The aim of this study is to investigate the long-term consequences of early malnutrition on beta-cell mass and function. Methods. Oral glucose tolerance tests were done in 3- and 12-month-old animals and beta-cell mass and apoptosis were determined by morphometrical measurements on pancreatic sections. The specific impact of postnatal malnutrition was studied by comparing control animals (C group) with animals malnourished during their fetal life only (R/C group), and animals malnourished during fetal life and until weaning (R group). Results. In 3-month-old R/C animals beta-cell mass reached 8.0 ± 1.5 mg with no further increase until 12 months (8.1 ± 1.5 mg), compared with 9.3 ± 1.9 mg in control rats. Twelve-month-old R/C animals showed normal plasma insulin responses and borderline glucose tolerance. In R animals, apoptosis reached 1.9 ± 0.4 % of the beta cells at 3 months, compared with 0.7 ± 0.5 % in control rats, and beta-cell mass did not increase between 3 and 12 months (4.7 ± 0.8 mg at 12 months). In aged control and R animals, apoptosis affected 8 % of the beta cells. At 12 months only, R animals showed profound insulinopenia and marked glucose intolerance. Conclusion/interpretation. In conclusion, perinatal malnutrition profoundly impairs the programming of beta-cell development. In animals with decreased beta-cell mass the additional demand placed by ageing on the beta cells entails glucose intolerance since beta-cell mass does not expand and apoptosis is increased. [Diabetologia (1999) 42: 711–718]
    Materialart: Digitale Medien
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  • 109
    ISSN: 1432-0428
    Schlagwort(e): Keywords Type I diabetes ; interferon-γ ; transgenic mice ; apoptosis ; insulin secretion ; tumour necrosis factor.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Aims/hypothesis. To examine whether interferon-γ destroys islet beta cells directly or indirectly through lymphocyte activation, or whether direct action of interferon-γ on beta cells by itself induces diabetes without insulitis. Methods. To avoid possible nonspecific breakdown of beta cells by transgenic overexpression of interferon-γ by the insulin promoter, we generated transgenic mice expressing interferon-γ under the control of rat glucagon promoter (RGP-IFN-γ-Tg mice). Results. The absence of insulitis in RGP-IFN-γ-Tg mice enabled us to investigate the direct effects of paracrine interferon-γ. In RGP-IFN-γ-Tg mice, serum concentrations of interferon-γ and tumour necrosis factor-α (TNF-α) were 50 and 6 times higher than those in their littermates, respectively, and glucose-responsive insulin secretion decreased to one-half the level of that in the littermates. Transgenic interferon-γ induced remodelling of beta cells where apoptosis of many beta cells was compensated by their vigorous regeneration and diabetes did not occur in most of the RGP-IFN-γ-Tg mice. Conclusion/interpretation. Interferon-γ alone is insufficient for the complete destruction of beta cells in vivo, and factors other than interferon-γ including activated lymphocytes or other cytokines, are necessary in addition to interferon-γ for the development of Type I (insulin-dependent) diabetes mellitus. [Diabetologia (1999) 42: 566–573]
    Materialart: Digitale Medien
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  • 110
    Digitale Medien
    Digitale Medien
    Springer
    Diabetologia 42 (1999), S. 55-59 
    ISSN: 1432-0428
    Schlagwort(e): Keywords Nicotinamide ; cytokine ; islet ; insulin ; apoptosis ; diabetes.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Nicotinamide intervention trials are presently undertaken to prevent Type I (insulin-dependent) diabetes in high risk subjects. They are based on studies in rodents reporting nicotinamide protection against beta-cell injury in vitro and in vivo. This study examines whether nicotinamide can protect human beta cells in vitro. At concentrations (2 and 5 mmol/l) to protect rat beta cells against necrosis by streptozotocin or hydrogen peroxide, nicotinamide prevents hydrogen peroxide-induced necrosis of human beta cells. As with rat beta cells, nicotinamide fails to protect human beta cells against apoptosis induced by a combination of the cytokines interleukin-1β , interferon-γ and tumour necrosis factor-α. In rat beta cells, nicotinamide (2 to 20 mmol/l) was also found to induce apoptosis, in particular during the days following its protection against necrosis; this cytotoxic effect was not observed with human beta cells. These data demonstrate that nicotinamide can protect human beta cells against radical-induced necrosis, but not against cytokine-induced apoptosis. This effect is not associated with a delayed apoptosis as in rat beta cells. [Diabetologia (1999) 42: 55–59]
    Materialart: Digitale Medien
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  • 111
    ISSN: 1423-0127
    Schlagwort(e): Tax ; HTLV-1 ; Trans-activation ; Phosphorylation ; Mutagenesis ; Transcription ; Genetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The human T cell leukemia virus type 1 (HTLV-1) Tax is a phosphoprotein, however, the contribution of phosphorylation to Tax activity is unknown. Previous studies have shown that phosphorylation of Tax occurs on serine residue(s), within one tryptic fragment, in response to 4β-phorbol-12β-myristate-13α-acetate, in both mouse and human cells. Studies were conducted in multiple cell lines to identify the specific phosphorylated serines as a prelude to functional analysis. The phosphorylation pattern of Tax was found to be different in 293T and COS-7 cells in comparison with MT-4 and Px-1 cells. However, one tryptic fragment remained consistent in comigration analyses among all cell lines. Using selected Tax serine mutants a tryptic fragment containing a serine at residue 113 believed to be the site of phosphorylation of Tax did not comigrate with the common phosphorylated tryptic fragment. Analysis of selected Tax mutants for ability totrans-activate the cytomegalovirus promoter demonstrated mutation of serine 77 to alanine reducedtrans-activation by 90% compared to wild-type Tax. However, examination of the phosphorylation pattern of the serine 77 mutant demonstrated that it is not the site of phosphorylation. These studies demonstrate the importance of using relevant cell lines to characterize the role of phosphorylation in protein function.
    Materialart: Digitale Medien
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  • 112
    ISSN: 1432-1963
    Schlagwort(e): Schlüsselwörter Rhadomyosarkom ; Klassifizierung ; Immunhistochemie ; Genetik ; Prognose ; Key words Rhabdomyosarcoma ; Classification ; Immunohistochemistry ; Genetics ; Prognosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary Rhabdomyosarcoma (RMS) is the most important and a very heterogeneous group of malignant soft tissue tumors of childhood and adolescence.The two major subtypes (embryonal and alveolar) share a common myogenic differentiation, but seem to be histogenetically not related. The so-called ’International Classification of Rhabdomyosarcoma’ includes, besides the two major subtypes, the botryoid and leiomyomatous subtypes of embryonal RMS which are associated with a better prognosis and are treated less aggressively according to current protocols. In addition, the solid variant of alveolar RMS is included in the alveolar group of RMS. The identification of the various subtypes is necessary and important because the treatment with the current protocols is also related to histology. Using conventional stains and immunohistochemistry, these subtypes are distinguishable. Genetic analysis can be helpful in the demonstration of t(2;13) or t(1;13) translocations in alveolar RMS. The identification of alveolar RMS with t(1;13) translocation might become important in the future, because this type of translocation seems to be related to a better prognosis as compared to tumors with a t(2;13) translocation.
    Notizen: Zusammenfassung Rhabdomyosarkome stellen eine heterogene Gruppe von ganz verschiedenartigen, histogenetisch wohl nicht zusammengehörenden Tumoren dar. Nach der heute verwendeten „Internationalen Klassifikation” der Rhabdomyosarkome werden neben der Unterteilung in embryonalen und alveoläre Rhabdomyossarkome auch Subtypen des embryonalen RMS identifiziert (botryoider und leiomyomatöser Subtyp), die durch eine günstigere Prognose und durch die Notwendigkeit einer weniger aggressive Therapie gekennzeichnet sind. Durch Einsatz von verschiedenen histologischen und immunhistochemischen Färbungen ist die Identifizierung der verschiedenen Typen der RMS heute möglich und auch zwingend notwendig, da die einzelnen Entitäten nach ganz unterschiedlichen Therapieprotokollen behandelt werden. Der Nachweis typischer molekulargenetischer Veränderungen kann in der Unterscheidung insbesondere von embryonalen und alveolären RMS hilfreich sein. In der Regel ist die Abgrenzung zwischen diesen beiden Entitäten auch an konventionell gefärbten Schnittpräparaten möglich. Die Identifizierung von alveolären RMS mit einer t(1;13)-Translokation könnte in Zukunft eine große Bedeutung haben, da diese genetische Veränderung möglicherweise mit einer günstigeren Prognose assoziert sein könnte als die t(2;13)-Translokation.
    Materialart: Digitale Medien
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  • 113
    Digitale Medien
    Digitale Medien
    Springer
    European journal of pediatrics 158 (1999), S. 302-307 
    ISSN: 1432-1076
    Schlagwort(e): Key words Congenital heart disease ; Pulmonary atresia and ventricular septal defect ; Genetics ; Monosomy 22q11.2
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The purpose of our study was to describe the prevalence and the clinical spectrum of monosomy 22q11.2 in a population of patients with pulmonary atresia and ventricular septal defect. We examined all 44 patients with this conotruncal cardiac malformation who presented to our institution from January 1994 until December 1997. The type of collateral lung perfusion was recorded including anomalies of the pulmonary arteries as well as facial and immunological abnormalities. Molecular-cytogenetic testing for a 22q11.2 microdeletion was performed using the probes D22S75 and cHKAD26. Statistical differences were evaluated with the Fisher's Exact Test. Monosomy 22q11.2 was present in ten children (23%) with major aortopulmonary collateral arteries (group 1). The remaining 13 children (29%) with major aortopulmonary collateral arteries (group 2) and all 21 children (48%) with ductus arteriosus (group 3) were negative for this microdeletion. All children in group 1 had facial anomalies, six had mild immunological abnormalities including decreased CD 4+ or CD 8+ cells. Anomalies of the pulmonary vascular bed were significantly more frequent in children of group 1 (9/10) than in children of group 2 (4/13) or group 3 (0/21). Due to these pulmonary vascular anomalies, corrective surgery had been accomplished in fewer children with monosomy 22q11.2 (none in group 1) as compared to 7/13 children in group 2 and 14/21 children in group 3. Conclusion In children with pulmonary atresia and ventricular septal defect, monosomy 22q11.2 is preferentially associated with major aortopulmonary collateral arteries. Due to the higher incidence of pulmonary arterial abnormalities, successful surgical repair will require a different therapeutic approach in most patients with this microdeletion.
    Materialart: Digitale Medien
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  • 114
    Digitale Medien
    Digitale Medien
    Springer
    Current genetics 35 (1999), S. 571-584 
    ISSN: 1432-0983
    Schlagwort(e): Key words Cytokinesis ; Kinase ; Mitosis ; Schizosaccharomyces pombe ; Cell division ; Phosphatase ; Mutant ; Genetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The fission yeast Schizosaccharomyces pombe provides a simple eukaryotic model for the study of cytokinesis. S. pombe cells are rod-shaped, grow mainly by elongation at their tips, and divide by binary fission after forming a centrally placed division septum. Analysis of mutants has begun to shed light upon how septum formation and cytokinesis are regulated both spatially and temporally. Some of the proteins involved in these events have been functionally conserved throughout eukaryotic evolution, suggesting that aspects of this control will be common to all eukaryotic cells.
    Materialart: Digitale Medien
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  • 115
    Digitale Medien
    Digitale Medien
    Springer
    Journal of neurology 246 (1999), S. 1140-1144 
    ISSN: 1432-1459
    Schlagwort(e): Key words Amyotrophic lateral sclerosis ; Genetics ; Glutamate transporter gene
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Amyotrophic lateral sclerosis (ALS) is a progressive neurological disorder characterised by degeneration of upper and lower motor neurons. Whilst the primary pathogenic trigger is unknown in most cases, evidence is mounting to implicate a role for glutamate-mediated neurotoxicity in the disorder. Recent studies have shown reduced levels of the mainly astroglial glutamate transporter EAAT2 in ALS motor cortex and spinal cord and multiple abnormal EAAT2 mRNA species in ALS brain tissue. One cause of the low EAAT2 levels may be that point mutations in the EAAT2 gene, EAAT2, result in an abnormal unstable protein. To test this hypothesis we analysed EAAT2 in 128 sporadic and 23 familial European ALS cases. No variants within the coding sequence of EAAT2 to affect the protein sequence nor in the consensus splice sites of the flanking intronic sequences were found in any cases, similar to findings in other reports. Frequent polymorphisms within the flanking intronic sequences of both exons 2 and 4 were seen but at similar frequencies in controls. Mechanisms other than mutations within the coding region of EAAT2 must therefore be responsible for the low levels of EAAT2 seen in most cases of ALS.
    Materialart: Digitale Medien
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  • 116
    Digitale Medien
    Digitale Medien
    Springer
    International journal of colorectal disease 14 (1999), S. 2-9 
    ISSN: 1432-1262
    Schlagwort(e): Key words Inflammatory bowel disease ; Crohn's disease ; Ulcerative colitis ; Epidemiology ; Genetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Inflammatory bowel diseases (IBD) are complex disorders. While the exact etiology of these diseases remains unknown, recent progress in the epidemiology and genetics of IBD has clearly demonstrated both environmental and genetic factors to play a role in the development of the disease, and it is expected that some risk factors are common for both Crohn's disease (CD) and ulcerative colitis (UC). The environmental factor(s) are associated with the Western way of life in the second half of the twentieth century. Cigarette smoking is presently the best known environmental factor. However, the effect of tobacco is opposite in CD and UC. A familial history of IBD is the most important risk factor for developing the disease, suggesting a genetic predisposition to IBD. This hypothesis has recently been confirmed by the localization of at least two susceptibility loci on chromosomes 12 and 16. These genes seem to play a role in both CD and UC. They must now to be identified.
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  • 117
    Digitale Medien
    Digitale Medien
    Springer
    Child's nervous system 15 (1999), S. 676-680 
    ISSN: 1433-0350
    Schlagwort(e): Key words Craniosynostosis ; Genetics ; FGFR ; Msx2 ; Development ; Skull
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The genetic studies of syndromic craniosynostoses lead to the characterisation of genes that regulate the correct development of the bones of the skull. From these studies, it appears that FGF/FGFR signalling has a crucial role in this problem. Numerous mutations affecting the genes coding for FGFR1, 2 or 3 are responsible for these syndromes. It is interesting to note that some identical mutations produced various different phenotypes, suggesting that other genes modulate the phenotypic expressivity. The other involved genes in these syndromes code for such proteins as Msx2 or Twist that interact in the cellular pathways responsible for FGF action. From these genetic studies, it is now important to establish the role of these proteins during the development of the skull. Msx2 plays a repressive role in osteogenesis, whereas FGFRs act as promoting proteins. In the near future, it will be very important to improve our understanding of these phenomena in order to test specific treatments to prevent the development of such syndromes.
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  • 118
    Digitale Medien
    Digitale Medien
    Springer
    Journal of neurology 246 (1999), S. 69-72 
    ISSN: 1432-1459
    Schlagwort(e): Key words Alzheimer’s disease ; Genetics ; Genetic counseling ; Predictive testing ; Diagnosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Alzheimer’s disease (AD) has a significant genetic background manifested as autosomal dominant inheritance in some early-onset families and as familial risk in late-onset cases. Three genes responsible for early-onset autosomal dominant AD have been identified, and one gene, apolipoprotein E, has been confirmed as a susceptibility gene for late-onset forms of the disorder. These findings raise the possibility of genetic testing, either for early diagnosis or prediction. For early-onset autosomal dominant AD genetic testing will have a limited but useful role in confirming diagnosis in established cases and in predictive counselling for relatives; a situation analogous to that for Huntington’s disease. For late-onset AD significant problems remain to be overcome before the advances in molecular genetics have a direct clinical application
    Materialart: Digitale Medien
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  • 119
    Digitale Medien
    Digitale Medien
    Springer
    Annals of oncology 10 (1999), S. 105-109 
    ISSN: 1569-8041
    Schlagwort(e): advanced pancreatic cancer ; chemotherapy ; clinical benefit
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Two case histories are reported here in which a chemotherapeutic approach improved the clinical conditions of patients with advanced pancreatic cancer. Until recently, chemotherapy was considered ineffective in pancreatic cancer, and most oncologists treated these patients with best-supportive-care only. Enthusiasm for systemic therapy of advanced pancreatic cancer is again growing, spurred by the advent of new drugs and new treatment endpoints such as life quality and symptom palliation. Gemcitabine, the most intensively- investigated new drug in pancreatic cancer, has shown an advantage in both survival and clinical benefit over that of 5-fluorouracil (5- FU). Other new drugs such as taxanes have shown interesting levels of activity, and are deserving of further evaluation. Although these results are far from conclusive and are only partially satisfactory, they represent a significant step forward in the treatment of advanced pancreatic cancer.
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  • 120
    Digitale Medien
    Digitale Medien
    Springer
    Annals of oncology 10 (1999), S. 139-150 
    ISSN: 1569-8041
    Schlagwort(e): apoptosis ; chemotherapy ; clinical trials ; gene therapy ; p53
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Nearly twenty years after the initial discovery of p53, we are now in an ideal position to exploit our vast knowledge of p53 biology in the creation of novel cancer therapies. Disruption of p53 function through mutation, or other means, occurs very frequently in human cancer. Loss of p53 function has been linked with unfavourable prognosis in a large number of tumour types, as indicated by more aggressive tumours, early metastasis and decreased survival rates. Many different avenues of research have converged upon p53 to highlight this protein as being one of the foremost cellular responders to stress, in particular to DNA damage. Huge advances have been made in understanding the complex role p53 plays in the regulation of apoptosis and cell cycle arrest. This review is not meant to be a comprehensive description of p53 biology, but rather serves to highlight current progress in the development of p53- oriented cancer therapies. These may be categorised into three basic strategies: gene replacement therapy using wild-type p53, restoration of p53 function by other means and, finally, targeting of the p53 dysfunction itself. Rapid progress is expected to be made regarding the identification of conventional pharmaceutical agents which either work in a p53-independent manner or act preferentially in p53 defective cells. Gene replacement therapy with wild-type p53 also holds considerable potential for obtaining clinically relevant results quickly. The other forms of cancer therapies based around p53 are much further behind in the developmental process, but may prove to more efficacious in the long run, especially in terms of specificity. As with many other fields, the innovation of successful p53-oriented cancer therapies is only limited by our understanding of p53 biology and the creative use of such knowledge.
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  • 121
    ISSN: 1569-8041
    Schlagwort(e): antiretroviral ; chemotherapy ; granulocyte-colony stimulating factor ; HIV infection ; Hodgkin's disease ; therapy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Background: The optimal therapeutic approach for patients with Hodgkin's disease and human immunodeficiency virus infection (HD–HIV) is unknown. In an attempt to improve the results previously obtained with EBV (epirubicin, bleomycin and vinblastine) without G-CSF (Cancer 1994; 73: 437–44), in January 1993 we started a trial using chemotherapy (CT) consisting of EBV plus prednisone (EBVP), concomitant antiretroviral therapy (zidovudine, AZT or dideoxinosyne, DDI) , and G-CSF. Patients and methods: Up to August, 1997, 35 (30 M/5 F) consecutive previously untreated patients (median age 34, range 21–53 years) with HD–HIV were enrolled in the European Intergroup Study HD–HIV. Their median performance status was 1 (range 1–3). At diagnosis of HD, 26% of the patients had AIDS, 90% had B symptoms at HD presentation and 83% had advanced-stage HD. Patients received E 70 mg/m2 i.v. on day 1, B 10 mg/m2 i.v. on day 1, V 6 mg/m2 i.v. on day 1 and P 40 mg/m2 p.o. from day 1 to day 5 (EBVP). Courses were repeated every 21 days for six cycles. AZT (250 mg × 2/day), or DDI (200 or 300 mg × 2/day) if AZT had been previously used, were given orally from the beginning of CT. G-CSF was given at the dose of 5 mcg/kg/day s.c. from day 6 to day 20 in all cycles. Results: An overall response rate of 91% was observed. There were 74% complete responses (CR) and 17% partial responses (PR). Toxicity was moderate, with grade 3–4 leukopenia and thrombocytopenia in 10 (32%) and three (10%) patients, respectively. The median number of administered cycles was 6 (range 3–6). Twenty-three of 35 patients received AZT and nine patients received DDI. Three (8%) patients had opportunistic infections (OI) during or immediately after CT. The median CD4+ cell count was 219/mm3 (6–812) at HD diagnosis and 220/mm3 (2–619) after the end of combined therapy, and these numbers remained unchanged. Ten of 26 (38%) patients who achieved CR relapsed. Twenty-three patients died of HD progression alone or in association with OI, being the cause of death in 48% and 9% of patients respectively. The median survival was 16 months, with a survival rate of 32% and a disease-free survival of 53% at 36 months. Conclusions: The combined antineoplastic and antiretroviral treatment is feasible, but HD in HIV setting is associated with a more adverse prognosis than in the general population. Although the CR rate obtained was satisfactory, the relapse rate was high. Furthermore, comparison of the results of our two consecutive prospective studies demonstrated no overall improvement in the current trial with respect to the CR rate and survival.
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  • 122
    Digitale Medien
    Digitale Medien
    Springer
    Annals of oncology 10 (1999), S. 1043-1049 
    ISSN: 1569-8041
    Schlagwort(e): chemotherapy ; non-small cell lung cancer ; NSCLC ; three-drugs combination
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Background: Paclitaxel, gemcitabine, and cisplatin are each active in non-small-cell lung cancer (NSCLC), and with different modes of action. Hence, a phase II study combining these drugs were conducted. Patients and methods: Treatment was paclitaxel 110 mg/m2 and cisplatin 60 mg/m2 day 1 and 15, with gemcitabine 800 mg/m2 day 1, 8, and 15, every four weeks. Patients had previously untreated NSCLC, measurable disease, age 18–70 years, performance status ≤2, and no brain metastases. Results: Among 49 patients, 6 (group 1) received chemotherapy as described above, while 43 patients (group 2) did not receive gemcitabine day 8. In group 1, all experienced grade 4 neutropenia and four achieved a partial response (67%). In group 2, neutropenia grade 4 occured in 58%, with one episode of febrile neutropenia and no toxic death. No other grade 4 toxicities occured, while grade 3 toxicity occured with respect to thrombocytopenia (9%), nausea/vomiting (12%), neurotoxicity (12%), and nephrotoxicity (7%). There were 3 complete and 20 partial responses (response rate 54%, 95% confidence limits 38%–69%), median response duration 29 weeks (range 10–66+), median time to progression 28 weeks (range 4–66+), median survival 46 weeks (4–89+) and one-year survival rate 42%. Conclusion: This regimen of paclitaxel, gemcitabine, and cisplatin has neutropenia as dose limiting toxicity, but septicemic episodes were rare and toxic death did not occur. Other grade 4 toxicities than neutropenia did not occur. The regimen appears safe and with a noteworthy activity both in terms of response rate, time to progression, and survival.
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  • 123
    ISSN: 1569-8041
    Schlagwort(e): chemotherapy ; non-metastatic osteosarcoma ; prognosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract This study evaluates histological response, long-term outcome, and toxicity in an intensive chemotherapy program given before surgery. Patients and methods: Sixty-two patients (39 males, 23 females; median age 14) with biopsy, chest computerised-tomography, technetium bone-scan and magnetic resonance imaging, were enrolled. Primary localisations were femur (44%) and tibia (26%). Induction chemotherapy involved seven courses of high-dose methotrexate and two courses of HELP (ifosfamide, eldesine (vindesine), cisplatin (platinum)–doxorubicin. After surgery, patients received six courses of high-dose methotrexate and two courses of HELP–doxorubicin. Results: Pre- and postoperative toxicities were similar. Fifty-nine patients underwent surgery: histological response was good in thirty-eight patients (64%) and poor in twenty-one (36%). Median follow-up is 57 months (range 30–80), with 77% overall survival and 59% progression-free survival. In a multivariate analysis, age under 10 years is the only prognostic factor that significantly correlates with outcome. Conclusions: This regimen appears to increase histological necrosis, but associates with severe toxicity. Results for patients with less necrosis at surgery are encouraging. Future trials should determine the minimum effective doses to reduce toxicity. New drugs should be added.
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  • 124
    Digitale Medien
    Digitale Medien
    Springer
    Annals of oncology 10 (1999), S. 17-20 
    ISSN: 1569-8041
    Schlagwort(e): advanced ovarian cancer ; chemotherapy ; duration ; treatment
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Documentation for the optimal duration of first-line chemotherapy in advanced ovarian cancer is limited. Three randomised trials have compared 5-6 cycles with 8, 10 and 12 cycles respectively. None of the studies showed benefit of chemotherapy beyond 6 cycles. At the moment the standard number of cycles therefore must be 6 cycles. However, these data are based on platinum poly-chemotherapy regimens without taxanes. It may be that the optimal number of cycles is different when using taxanes regimens. It is not possible to tell from the literature if there is a relationship between the number of cycles and response or between the cumulative dose and response. At the moment no trial has shown any benefit of high-dose intensity chemotherapy administered over a short time compared with standard dose chemotherapy administered over a longer period.
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  • 125
    ISSN: 1569-8041
    Schlagwort(e): cervical cancer ; chemotherapy ; cisplatin ; ifosfamide ; paclitaxel ; survival
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Purpose: The results of salvage chemotherapy for recurrent or persistent squamous-cell cervical cancer are unsatisfactory. Cisplatin and Ifosfamide are effective compounds in cervical cancer. Paclitaxel has recently been tested with promising results. The aim of this study was to assess the efficacy of a combination of paclitaxel, ifosfamide and cisplatin (TIP) for persistent/recurrent squamous-cell cervical carcinoma in a phase II trial. Patients and methods: Forty-five women were treated with the TIP regimen. Thirty-one had received prior irradiation. Paclitaxel was given at a dose of 175 mg/m2, ifosfamide at a dose of 5 g/m2, and cisplatin at a dose of 75 mg/m2 (50 mg/m2 in irradiated patients) at three-week intervals. Results: We observed 15 clinical complete responses, 15 partial responses, 9 stable diseases and 6 progressions. The objective response rate was 67% (95% confidence interval: 51%–81%). Ten complete responders underwent subsequent surgery and seven had pathology-defined complete responses (two in irradiated areas). The response rate was 52% in irradiated and 75% in non-irradiated areas. The median survival for non-responders is 6 months, 9+ month for partial responders and 13+ for complete responders. The most relevant side effect was myelotoxicity, with 91% of patients experiencing grade 3–4. One woman had life-threatening toxic effects. Conclusions: This combination is highly effective for salvage treatment in non-irradiated patients. For irradiated women the response rate is higher than that observed with other regimens but further investigation is warranted. The toxicity is relevant but adequate hydration and prolonged infusion of ifosfamide make it acceptable.
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  • 126
    Digitale Medien
    Digitale Medien
    Springer
    Annals of oncology 10 (1999), S. 122-126 
    ISSN: 1569-8041
    Schlagwort(e): apoptosis ; biliary carcinogenesis ; cholangiocarcinoma ; genotoxicity ; risk factors ; therapeutic strategies
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Carcinomas of the biliary tract are rare cancers developing from the epithelial or blast-like cells lining the bile ducts. A variety of known predisposing factors and recent experimental models of biliary carcinogenesis (e.g., infection with the liver fluke Opisthorchis viverrini, models of chemically induced carcinogenesis and experimental models of pancreaticobiliary maljunction) have elucidated different stages of this complex system of biliary tumorigenesis. Chronic inflammatory processes, generation of active oxygen radicals, altered cellular detoxification mechanisms, activation of oncogenes, functional loss of tumor-suppressor genes and dysregulation of cell proliferation and cell apoptotic mechanisms have been identified as important contributors in the development of cholangiocarcinomas. In this review, the known mechanisms involved in the carcinogenesis of biliary epithelium are addressed. We will divide the topic into four stages: 1) Predisposition and risk factors of biliary cancer, 2) Genotoxic events and alterations leading to specific DNA damage and mutation patterns. 3) Dysregulation of DNA repair mechanisms and apoptosis, permitting survival of mutated cells and 4) Morphological evolution from premalignant biliary lesions to cholangiocarcinoma. Finally, established and hypothetical future therapeutic strategies directed towards specific pathogenetic events during biliary carcinogenesis will be addressed.
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  • 127
    Digitale Medien
    Digitale Medien
    Springer
    Annals of oncology 10 (1999), S. 185-187 
    ISSN: 1569-8041
    Schlagwort(e): chemotherapy ; endocrine tumours ; immunotherapy ; interferon
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The various pancreatic endocrine tumors (PETs) share histological features with each other and with the carcinoid. The aspects of chemotherapy and/or interferon concern the management of metastatic disease. The value of chemotherapy is difficult to evaluate from the literature because often no distinction is made between the various types of PETs and carcinoids are often also included. Moreover, it has been shown that not each tumor responds equally to chemotherapy, depending on a functioning or non-functioning state of the tumor. In general the response rate to any cytostatic drug, single agents or combinations, is low.
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  • 128
    Digitale Medien
    Digitale Medien
    Springer
    Annals of oncology 10 (1999), S. 305-307 
    ISSN: 1569-8041
    Schlagwort(e): biliay tract cancer ; chemotherapy ; 5-fluorouracil ; gemcitabine ; intra-arterial chemotherapy ; pancreatic cancer ; regional chemotherapy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Chemotherapy of carcinomas of the pancreas and biliary tract has always been of limited value. Pancreatic cancer is well known for its aggressive nature, poor prognosis and resistance to antineoplastic agents which are effective in other solid tumors. 5-Fluorouracil has long been the mainstay of the treatment of pancreatic cancer, although the response rate to this agent is 〈10% and the influence on survival and quality of life is neglegible. Combination chemotherapy in pancreatic cancer adds to the side effects of treatment, but has had no proven effect on effectiveness. The only new anticancer drug of which an improvement in clinical benefit has been indicated on the basis of randomized clinical research, is gemcitabine, although the magnitude of improvement is limited. Due to the rarity of tumors of the biliary tract, the data on the effect of chemotherapy in this disease is sparse but does not suggest that it leads to superior results than supportive care alone. Likewise, no literature exists supporting the routine application of regional chemotherapy infusion in these type of tumors.
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  • 129
    ISSN: 1569-8041
    Schlagwort(e): acute myelogenous leukemia ; apoptosis ; ara-CTP ; cytosine arabinoside ; HL-60 ; retinoic acid
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Background: Accumulation of the cytosine arabinoside (ara-C) metabolite ara-C-triphosphate (ara-CTP) in leukemic blast cells is considered to be the main determinant of ara-C cytotoxicity in vitro and in vivo. Retinoids such as all-trans-retinoic acid (ATRA) have been shown to increase the sensitivity of acute myelogenous leukemic (AML) blast cells to ara-C. To investigate the mechanism of this sensitisation, the hypothesis was tested that ATRA augments cellular ara-CTP levels in human-derived myelogenous leukemia HL-60 cells. Materials and methods: The effect of ATRA and 13-cis-retinoic acid on ara-CTP accumulation and ara-C-induced apoptosis was studied. Ara-CTP levels were measured by high-performance liquid chromatography (HPLC), cytotoxicity by the tetrazolium (MTT) assay, and apoptosis by occurrence of DNA fragmentation (gel electrophoresis), cell shrinkage and DNA loss (flow cytometry). Results: Pretreatment of HL-60 cells with ATRA (0.01–1 µM) caused a significant decrease in intracellular ara-CTP levels; e.g., incubation for 72 hours with ATRA 1 µM prior to one hour ara-C 10 µM reduced ara-CTP levels to 41% ± 4% of control. Similar results were obtained after preincubation with 13-cis-retinoic acid. In spite of decreased ara-CTP levels, the cytotoxicity of the combination was supraadditive and ATRA augmented ara-C-induced apoptosis. Conclusions: At therapeutically relevant concentrations ATRA increased ara-C cytotoxicity and ara-C induced apoptosis but this augmentation is not the corollary of elevated ara-CTP levels. The feasibility of ara-C treatment optimisation via strategies other than those involving elevation of ara-CTP levels should be investigated further.
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  • 130
    Digitale Medien
    Digitale Medien
    Springer
    Annals of oncology 10 (1999), S. 139-146 
    ISSN: 1569-8041
    Schlagwort(e): anthracycline ; breast cancer ; chemotherapy ; HER-2 antibody ; N,N-diethyl-2[4-(phenylmethyl)-phenoxy] ethanamine.HCl (DPPE, BMS-217380-01) ; paclitaxel
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Anthracyclines and taxanes are the two most active classes of chemotherapy for the treatment of advanced breast cancer. Recent studies have investigated combination therapy including doxorubicin (Dox) and paclitaxel. The efficacy of this combination has been established in a phase III study conducted by ECOG, comparing Dox/paclitaxel versus Dox versus paclitaxel. The combination is superior to Dox or paclitaxel with respect to response rate and time to disease progression, indicating that the combination provides a new standard for the first line treatment of metastatic breast cancer [1]. Phase II studies using higher doses of Dox and using shorter infusions of paclitaxel have suggested the combination can be further optimised; Gianni reported a 94% objective response rate using Dox 60 mg/m2 followed by paclitaxel 175 mg/m2 given over three hours [2]. The more active regimens are associated with enhanced cardiotoxicity; this toxicity can be avoided, however, by limiting the exposure to doxorubicin. The newer regimens have now been moved into phase III studies. Future progress for this disease will depend on the introduction of new agents. Two novel drugs are currently being investigated in randomised phase III trials as potentiators of Dox and/or paclitaxel. One is a monoclonal antibody from Genentech (Herceptin, trastuzumab) directed at the HER-2/neu oncogene, which is overexpressed in 〉25% of breast cancers [3]. Recent results indicate that Herceptin in combination with paclitaxel (or with a Dox plus cyclophosphamide regimen) induces a higher response rate (RR) and prolongs the time to disease progression when compared to chemotherapy alone. The second agent N,N-diethyl-2[4-(phenylmethyl)-phenoxyl] ethanamine.HCl (DPPE, BMS-217380-01), when combined with Dox, was associated with a higher RR than previously observed with Dox alone [4]. A randomised trial of Dox versus Dox plus DPPE is ongoing. The possible mechanisms underlying chemo-potentiation by these agents are discussed. As new anthracycline/taxane combinations establish themselves in earlier stages of the disease, the need for effective, non-cross resistant salvage regimens will emerge.
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  • 131
    Digitale Medien
    Digitale Medien
    Springer
    Annals of oncology 10 (1999), S. 1475-1483 
    ISSN: 1569-8041
    Schlagwort(e): chemotherapy ; cisplatin ; long-term toxicity ; testicular cancer
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Background: The prognosis of advanced testicular cancer has improved considerably after the introduction of cisplatin-based combination chemotherapy. The improved prognosis of testicular cancer has brought the long-term toxicity of the treatment into focus. Patients and methods: Long-term toxicity was investigated prospectively intil more than 10 years after after treatment in a group of 22 patients treated with six series of cisplatin based chemotherapy (PVB) for testicular cancer. We have focused on nephro-, neuro-, pulmonary-, and gonadal toxicity. Results: Glomerular filtration rate (GFR) decreased significantly during treatment but increased during follow-up and all the patients had normal values of GFR 10–15 years after treatment. Carbon monoxide diffusion capacity (TLco) decreased during PVB treatment in smokers. TLco remained unchanged during the first years after PVB treatment, but improvement of TLco was seen in some patients more than 43 months after treatment. Paresthesia was reported by 83% of the patients immidiately after treatment, 50% at follow-up 4–9 years after chemotherapy and 14% prevalence 11–15 hears after treatment. The reported decline in neurotoxicity was verified by normalisation of vibration perception. Gonadal toxicity was severe and persistent although improvement was seen in a few patients even many years after treatment. Conclusions: The patients treated with PVB were physically and socially well-being at follow-up investigation 11–15 years after treatment. Improvements in pulmonary- and renal function, and recovery from neurotoxicity was seen during the long-term follow-up periode. Gonadal toxicity was severe and persistent.
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  • 132
    Digitale Medien
    Digitale Medien
    Springer
    Annals of oncology 10 (1999), S. 157-161 
    ISSN: 1569-8041
    Schlagwort(e): chemotherapy ; 5-fluorouracil ; gemcitabine ; pancreatic cancer ; pancreaticobiliary cancer
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract At time of presentation the majority of patients with pancreaticobiliary cancer have locally advanced or metastatic disease which makes them unamenable for curative surgery. In these patients chemotherapy is an option which has gained more support over the past few years. Special problems faced in chemotherapeutic treatment are the patient's poor condition and the difficulties faced in evaluating response. 5-FU has been the only drug with some efficacy for a long time, but more recently gemcitabine appeared to be more efficient. In locally advanced pancreatic cancer the combination of chemotherapy with radiotherapy has not gained much support. However, studies are implicating better local control with combined treatment and recurrences appear more often at distant sides. In some cases irresectable tumors became resectable. Because of the poor survival after surgery with curative intent, adjuvant and neoadjuvant therapy are becoming important issues. Although studies of adjuvant therapy suggest benefit, research is seriously hampered by poor patient accrual due to the morbidity of pancreaticoduodenectomy. Neoadjuvant treatment may overcome this problem. Until now there has been only modest improvement in the treatment of pancreatic cancer. Hopefully, new treatment modalities such as immunotherapy, gene therapy and antiangiogenic therapy will alter this dismal picture. In biliary cancer the role of chemotherapy is less well defined, since only few studies with low patients numbers have been performed.
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  • 133
    Digitale Medien
    Digitale Medien
    Springer
    Annals of oncology 10 (1999), S. 234-238 
    ISSN: 1569-8041
    Schlagwort(e): chemotherapy ; 5-fluorouracil ; gemcitabine ; pancreatic carcinoma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The current role of chemotherapy in pancreatic cancer is limited. Chemotherapy usually consists of 5-fluorouracil (5FU) and gemcitabine either as a single agent or in combinations. However, response rates are below 15% with minor effects on overall survival. Due to the aggressive behavior of the disease, current emphasis of new experimental chemotherapy is also focusing on clinical benefit: improvement of pain, performance status or weight. The results with gemcitabine indicated that evaluation of new chemotherapeutic agents in pancreatic cancer should not be limited to the evaluation of response rates; single agent gemcitabine not only showed higher response rates than 5FU, but also resulted in clinical benefit for the patients. Several new agents have been introduced into the clinic for treatment of various gastro-intestinal malignancies, whereas novel agents with different types of targets, such as marimastat deserve further attention. Several oral formulations of 5FU, such as capecitabine, UFT, and eniluracil with 5FU, aim to simulate long-term continuous infusion. Response rates of these formulations are comparable to those of 5FU continuous infusion and 5FU bolus injections. However, the convenience of oral administration with reliable plasma drug concentrations makes these agents very attractive as a replacement of traditional 5FU administration. Since 5FU acts by inhibition of thymidylate synthase (TS), resulting in inhibition of DNA synthesis, several new antifolates, directed towards TS, have been developed. However, these agents, such as ZD1694 (Tomudex, Raltitrexed) and LY231514 (MTA, multitargetted antifolate) showed only limited efficacy. Other new agents active in colorectal cancer, e.g. the topoisomerase I inhibitors topotecan and CPT-11, showed only minor activity. The same was observed for the taxanes. Combinations of gemcitabine (cisplatin, 5FU, epirubicin, marimastat) show promising activities, not only regarding response but also with respect to clinical benefit. The effects were better than that for each agent separately. Thus, despite limited activity of single agents, novel combinations especially with gemcitabine are promising, with emphasis on improvement of the clinical benefit of patients.
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  • 134
    Digitale Medien
    Digitale Medien
    Springer
    Annals of oncology 10 (1999), S. 77-82 
    ISSN: 1569-8041
    Schlagwort(e): chemotherapy ; non-small cell lung cancer
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Until recently the role of chemotherapy in NSCLC has generally been questioned. Major concerns included marginal activity, considerable toxicity and high cost of this treatment. There has, however, been increasing evidence from individual studies and meta-analyses that chemotherapy in advanced NSCLC is able to increase survival and improve quality of life. In the past few years a series of active drugs (paclitaxel, docetaxel, gemcitabine, vinorelbine, topotecan and irinotecan) with novel mechanisms of action and favourable toxicity profiles have been developed. These agents appear to hold the promise of added therapeutic benefit. In consequence, chemotherapy has currently been considered an important part of the standard treatment in selected patients with advanced NSCLC. Despite recent developments, treatment outcomes in advanced NSCLC remain far from satisfactory, and new effective means are desperately needed if more patients are to enjoy the prospects of long-term survival.
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  • 135
    ISSN: 1569-8041
    Schlagwort(e): chemotherapy ; osteosarcoma ; relative dose intensity ; survival ; tumour response
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Background: Despite advances in the treatment of primary limb osteosarcoma, the outcome of patients with primary metastatic and axial skeletal disease remains poor. The European Osteosarcoma Intergroup have assessed a combination chemotherapy regimen consisting of ifosfamide (IFOS) 3 g/m2/d1–2, doxorubicin (DOX) 25 mg/m2/d1–3 i.v. bolus and cisplatin (CDDP) 100 mg/m2/d1. Patients and methods: One hundred nine previously untreated patients with primary osteosarcoma were registered. Eligibility was confirmed in 103. At presentation, 45 eligible patients had metastatic disease, 15 axial skeletal primary tumours and 43 non-metastatic limb tumours. Results: The major toxicities were myelosuppression (90%, grade 3 or 4) and nausea and vomiting (74%, grade 3 or 4). Overall mean relative dose intensity (RDI) was 80% (88% CDDP, 75% IFOS, 81% DOX). Clinical response as measured by reduction in tumour volume occurred in 36% (95% confidence interval (95% CI): 27%–47%) of primary tumours. Response of pulmonary metastases to chemotherapy was seen in 33% (95% CI: 19%–49%). Good histological response (≥90% necrosis of the tumour) occurred in 33% (95% CI: 22%–45%) of resected tumours. Five-year survival was 62% in limb-non-metastatic, 41% in axial skeletal and 16% in limb metastatic patients. Conclusions: This regimen is active in osteosarcoma but does not appear to be more active than the two-drug CDDP–DOX regimen currently recommended by EOI.
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  • 136
    ISSN: 1569-8041
    Schlagwort(e): chemotherapy ; drugs ; generics ; prioritization
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The WHO has previously produced recommendations on the essential drugs required for cancer therapy. Over the last five years several new anti cancer drugs have been aggressively marketed. Most of these are costly and produce only limited benefits. We have divided currently available anti-cancer drugs into three priority groups. Curable cancers and those cancers where the cost-benefit ratio clearly favours drug treatment can be managed appropriately with regimens based on only 17 drugs. All of these are available, at relatively low cost, as generic preparations. The wide availability of these drugs should be the first priority. The second group of drugs may have some advantages in certain clinical situations. Based on current evidence, drugs in the third group are judged as currently not essential for the effective delivery of cancer care. Adequate supportive care programmes with the widespread availability of effective drugs for pain control are of considerably greater importance. The adoption of these priorities will help to optimise the effectiveness and efficiency of chemotherapy and ensure equitable access to essential drugs especially in low resource environments. Clearly this paper represents the views of its contributors. The WHO welcomes feedback from all oncologists so that the advice it gives to governments in prioritising the procurement of anti cancer drugs can be as comprehensive as possible.
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  • 137
    ISSN: 1569-8041
    Schlagwort(e): chemotherapy ; hematopoietic growth-factor support ; high-dose chemotherapy ; peripheral blood stem-cell transplantation ; small-cell lung cancer ; treatment toxicity and mortality
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Background: We conducted a phase I–II trial to assess the feasibility and activity of a combination chemotherapy regimen with etoposide, ifosfamide, cisplatin or carboplatin, and epirubicin in limited-disease (LD, stages I–IIIB) and extensive-stage (ED, stage IV) small-cell lung cancer (SCLC). Patients and methods: Standard-dose chemotherapy (SDC) consisting of etoposide (500 mg/m2), ifosfamide (4000 mg/m2), cisplatin (50 mg/m2) and epirubicin (50 mg/m2) (VIP-E), followed by granulocyte colony-stimulating factor (G-CSF), was given to 100 patients with SCLC. Thirty patients with qualifying responses to VIP-E proceeded to high-dose chemotherapy (HDC) with autologous peripheral blood stem-cell transplantation (PBSCT) after etoposide (1,500 mg/m2), ifosfamide (12,000 mg/m2), carboplatin (750 mg/m2) and epirubicin (150 mg/m2) (VIC-E) conditioning. Results of standard-dose VIP-E: Ninety-seven patients were evaluable for response. The objective response rate was 81% in LD SCLC (33% CR, 48% PR; excluding patients in surgical CR) and 77% in ED SCLC (18% CR, 58% PR). The treatment-related mortality (TRM) of SDC was 2%. Two additional patients in CR from their SCLC developed secondary non-small-cell lung cancers (NSCLC), and both were cured by surgery. The median survival was 19 months in LD SCLC and 6 months in ED SCLC. The five-year survivals were 36% in LD and 0% in ED SCLC. Results of high-dose VIC-E: HDC was feasible in 16% of ED-, and 58% of LD-patients. All HDC patients (n = 30) improved or maintained prior responses. Four patients died of early treatment-related complications (TRM 13%). Two additional patients in CR from their SCLC developed secondary malignancies (esophageal cancer, secondary chronic myelogenous leukemia). The median survivals were 26 months in LD SCLC, and 8 months in ED SCLC. The five-year survival was 50% in LD and 0% in ED SCLC. Conclusions: Despite high response rates, survival after VIP-E SDC and VIC-E HDC in patients with ED SCLC is not superior to that achieved with less toxic traditional regimens. The high five-year survival rates achieved with these protocols in LD SCLC probably reflect both patient selection (high proportion of patients with prior surgical resection) and the high activity of our chemotherapy regimen in combination with radiotherapy. A study comparing protocols using simultaneous radiation therapy and chemotherapy, and other dose-escalated forms of SDC with HDC is needed to further define the role of this treatment modality in SCLC. Given the high rate of secondary malignancies observed in patients in CR 〉2 years in our study, close follow-up and early treatment of these neoplasms may contribute to maintaining overall survival in patients with SCLC.
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  • 138
    Digitale Medien
    Digitale Medien
    Springer
    Annals of oncology 10 (1999), S. 231-233 
    ISSN: 1569-8041
    Schlagwort(e): chemoradiation ; chemotherapy ; 5FU ; gemcitabine ; radiotherapy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Chemoradiation for gastrointestinal cancers is actively under study in the Radiation Therapy Oncology Group (RTOG) and consists of external irradiation combined with simultaneously administered chemotherapy given to provide radiation sensitization and to attack micro metastatic disease. Two national protocols for the treatment of patients with pancreatic and biliary cancers are now active. RTOG 97-04 is a phase III post-operative combined modality program for patients with resected pancreatic cancer. All patients receive protracted infusional 5-fluorouracil (5-FU) combined with 50.4 Gy given in 28 fractions. Prior to and after chemoradiation all patients are randomized to receive multiple cycles of either infusional 5-FU or Gemcitabine to determine the effect on survival. In the other study (RTOG 98-12) patients with unresectable pancreatic cancer are given 50.4 Gy combined with weekly Paclitaxel (50 mg/m2) to examine the efficacy of this active combination in a phase II trial in a multi-institutional setting. Both of these trials have recently been opened to accrual. A third RTOG study for patients with biliary cancer will examine the efficacy of giving pre-operative chronomodulated infusional 5-FU chemoradiation. The background and the rationale for these studies is based on the long history of 5-FU radiation sensitization in the treatment of cancers of these anatomic sites and will be summarized. A brief review of recently published trials using chemoradiation in conjunction with new irradiation treatment techniques with "3D" conformal therapy for these diseases will be discussed.
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  • 139
    Digitale Medien
    Digitale Medien
    Springer
    Annals of oncology 10 (1999), S. 753-759 
    ISSN: 1569-8041
    Schlagwort(e): chemotherapy ; brain metastases ; lung cancer
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract In lung cancer patients brain metastases develop with a high frequency. For years radiotherapy has been the standard treatment for these patients. Here we review the experience with chemotherapy for brain metastases in lung cancer patients. The concept of the brain as pharmacological sanctuary site when brain metastases are present is challenged and it is argued that chemotherapy does play a role in this situation. Recent clinical trials indicate that the combination of chemotherapy and radiotherapy may become the standard treatment for lung cancer patients with brain metastases. It is unclear whether for micrometastatic disease to the brain, blood brain barrier function is of importance for the outcome of chemotherapy in lung cancer patients with respect to the development of overt brain metastases. Areas of improvement of delivery of cytotoxic agents to the brain when brain metastases have not yet developed are discussed.
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  • 140
    Digitale Medien
    Digitale Medien
    Springer
    Annals of oncology 10 (1999), S. 891-898 
    ISSN: 1569-8041
    Schlagwort(e): brachytherapy ; chemotherapy ; hormonal therapy ; prostate cancer ; recent advances
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract As new evidence for prostate cancer treatment has emerged in the last few years, longstanding controversies in the treatment of prostate cancer have resurfaced. A number of long-held tenets of prostate cancer therapy have been revisited, sometimes with surprising and challenging results. Although neoadjuvant hormonal therapy prior to radical prostatectomy decreases positive surgical margin rates, longer follow-up is needed to support survival improvement of this combined modality therapy. Androgen deprivation combined with radiation therapy appears to improve disease-free survival (and survival in one series) in patients with locally advanced cancer. Another approach to locally advanced prostate cancer using three-dimensional conformal radiation therapy may improve long term outcome. The data are currently insufficient to conclude that interstitial low dose rate brachytherapy is equivalent to conventional treatments: patients with small tumor volumes and low Gleason grade seem to obtain more benefit, whereas for large tumors with higher gleason grades this approach seems inferior to conventional treatments. In advanced prostate cancer recent data suggest that immediate hormonal therapy improves survival. In this group of patients the use of maximum androgen blockade remains controversial but may adversely affect quality of life compared to orchiectomy alone. Intermittent hormonal therapy may improve quality of life, although effect upon survival is unknown. Chemotherapy in combination with androgen deprivation is currently being studied as front-line therapy in advanced prostate cancer. Palliative benefit of chemotherapy for hormone refractory prostate cancer remains an important endpoint; survival advantage has not been seen in any randomized trials. Suramin may delay disease progression in hormone refractory prostate cancer. Many aspects of prostate cancer treatment will remain controversial until results of large, randomized trials with longer follow-up are available.
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  • 141
    Digitale Medien
    Digitale Medien
    Springer
    Journal of thermal analysis and calorimetry 55 (1999), S. 797-806 
    ISSN: 1572-8943
    Schlagwort(e): cadmium coordination ; crystal structure ; enthalpy of solution ; lattice energy ; lattice enthalpy ; NTO salt ; preparation ; standard enthalpy of dehydration ; standard enthalpy of formation ; thermal decomposition mechanism
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract [Cd(NTO)4Cd(H2O)6]·4H2O was prepared by mixing the aqueous solution of 3-nitro-1,2,4-triazol-5-one and cadmium carbonate in excess. The single crystal structure was determined by a four-circle X-ray diffractometer. The crystal is monoclinic, space group C2/c with crystal parameters of a=2.1229(3) nm, b=0.6261(8) nm, c=2.1165(3) nm, β=90.602(7)°, V=2.977(6) nm3, Z=4, Dc=2.055 g·cm−3, μ=15.45 cm−1, F(000)=1824, λ(MoKα)=0.071073 nm. The final R is 0.0282. Based on the results of thermal analysis, the thermal decomposition mechanism of [Cd(NTO)4Cd(H2O)6]·4H2O was derived. From measurements of the enthalpy of solution of [Cd(NTO)4Cd(H2O)6]·4H2O in water at 298.15 K, the standard enthalpy of formation, lattice energy, lattice enthalpy and standard enthalpy of dehydration have been determined as -(1747.8±4.8), -2394, -2414 and 313.6 kJ mol−1 respectively.
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  • 142
    ISSN: 1572-9001
    Schlagwort(e): Tetrahydrotetrol ; polycyclic aromatic hydrocarbon derivative ; carcinogen ; crystal structure ; structure-activity relationship
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract The molecular structures of two racemic trans-tetrahydrotetrols formed by hydrolysis of the (±)anti-7,8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydro derivatives of the strong carcinogen benzo[a]pyrene and the weak carcinogen chrysene have been determined by X-ray crystallographic methods.3 Focusing on the (+)isomers, the stereochemical features of the two tetrols are discussed in detail to determine structural differences, which can be related to the different biological activity of their parent hydrocarbons, since they provide a model for the hydrocarbon moiety in the major PAH-DNA adduct. As a result of this study, a tentative correlation can be stated between biological activity of quasi-planar bay-region PAHs and the presence of structural features, which can decrease the steric hindrance of the aromatic skeleton and the other hydroxy groups on the pseudo-axial O4, which mimics the position of the covalent bond to DNA. The significant structural features seem to be an out-of-plane distortion with a negative torsion angle at the bay region and a half chair conformation of the saturated ring distorted toward the envelope with C8 at the tip as in BPT, in addition to the axial and pseudo-axial conformations of the hydroxy groups at C9 and C10 due to the near bay region. They may be considered generated by trans-opening of the oxirane ring in an anti-diol epoxide biologically active because it is highly strained. The strains, derived from the activation of bay-region PAHs with a negative torsion angle, seem greater in an anti-diol epoxide relative to the syn-isomer. Thus, when the strains are released, the derived trans-tetrol occurs with structural features, which seem to better fit the target. As a consequence, the presence of a methyl group at a bay region should increase the biological activity of a PAH, imposing greater strains to the structure of the anti-diol epoxide.
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  • 143
    Digitale Medien
    Digitale Medien
    Springer
    Journal of thermal analysis and calorimetry 57 (1999), S. 807-821 
    ISSN: 1572-8943
    Schlagwort(e): bibliography ; critical temperature ; crystal structure ; CuRh2S4 ; CuRh2Se4 ; survey of chalcogenide superconductors
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract The thread that runs through all research in the field of superconductivity is new physics through discovery of new materials. The knowledge of superconducting materials has become voluminous and complex. The comprehensive review of the superconducting materials is of particular importance. The main purpose of this report is to present the results of classification for chalcogenide superconductors. Superconducting critical temperature Tc, crystal-structure type and the references proper to these compounds are summarized. Brief survey of the superconductivity in chalcogen elements is also given. Furthermore, as representative sulfide and selenide, superconducting characteristics of CuRh2S4 and CuRh2Se4 will be shown.
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  • 144
    Digitale Medien
    Digitale Medien
    Springer
    Journal of thermal analysis and calorimetry 58 (1999), S. 257-267 
    ISSN: 1572-8943
    Schlagwort(e): crystal structure ; lattice energy ; lattice enthalpy ; lead salt of NTO ; preparation ; quantum chemical calculation ; thermal decomposition mechanism
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract The single crystal of lead salt of 3-nitro-1,2,4-triazol-5-one (NTO), [Pb(NTO)2(H2O)] was prepared and its structure was determined by a four-circle X-ray diffractometer. The crystal is monoclinic, its space group is P21/n with crystal parameters of a=0.7262(1) nm, b=1.2129(2) nm, c=1.2268(3) nm, β=90.38(2)°, V=1.0806(2) nm3, Z=4, Dc=2.97 g cm−3, µ=157.83cm−1, F(000)=888. The final R is 0.027. By using SCF-PM3-MO method we obtained optimized geometry for [Pb(NTO)2⋅H2O] and particularly positions for hydrogen atoms. Through the analyses of MO levels and bond orders it is found that Pb atom bond to ligands mainly with its 6pz and 6py AOs. The thermal decomposition experiments are elucidated when [Pb(NTO)2⋅H2O] is heated, ligand water is dissociated first and NO2 group has priority of leaving. Based on the thermal analysis, the thermal decomposition mechanism of [Pb(NTO)2⋅H2O] has been derived. The lattice enthalpy and its lattice energy were also estimated.
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  • 145
    ISSN: 1572-9001
    Schlagwort(e): Nickel complex ; dithiocarbimate ; sulfonamide ; crystal structure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Potassium N-4-methylphenylsulfonyldithiocarbimate, K2(4-CH3C6H4SO2N=CS2), reacted with nickel(II) chloride hexahydrate and tetrabutylammonium bromide to form the bis(N-4-methylphenylsulfonyldithiocarbimate)nickelate(II) tetrabutylammonium salt (Bu4N)2[Ni(4-CH3C6H4S2C=NSO2)2]. The elemental analyses, IR and UV-Vis data obtained were consistent with the formation of a $${\text{nickel}}{\kern 1pt} - {\kern 1pt} {\text{sulfur}}$$ diamagnetic planar complex. The 1H NMR and the 13C NMR spectra showed the expected signals for the dithiocarbimate moiety and the tetrabutylammonium cation. The single-crystal structure analysis showed that this substance crystallizes in the triclinic $${P\bar 1}$$ space group with a = 10.474(3) Å, b = 10.767(3) Å, c = 13.657(3) Å and α = 81.54(2)°, β = 80.44(2)°, γ = 67.63(2)°, V = 1398.5(8) Å3, and Z = 2. The nickel atom is coordinated to four sulfur atoms.
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  • 146
    ISSN: 1572-9001
    Schlagwort(e): Nicotine-derived nitrosaminoketone ; nitrosamine ; crystal structure ; molecular dimensions
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract The three-dimensional structure of the carcinogenic nicotine-derived nitrosaminoketone, 4-(methyl-nitrosamino)-l-(3-pyridyl)-l-butanone, has been determined by X-ray crystallographic techniques. The molecule is essentially planar except for the methylnitrosamine group which is oriented at a dihedral angle of 68.7° to the pyridine ring. Molecules pack by way of —H⋯O interactions that involve the —NNO group.
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  • 147
    Digitale Medien
    Digitale Medien
    Springer
    Molecular and cellular biochemistry 196 (1999), S. 13-21 
    ISSN: 1573-4919
    Schlagwort(e): apoptosis ; DNA fragmentation ; GSHPx-1 knockout mice ; GSHPx-1 transgenic mice ; ischemia/repurfusion
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Abstract Apoptosis, a genetically controlled programmed cell death, has been found to play a role in ischemic reperfusion injury in several animal species including rats and rabbits. To examine whether this is also true for other animals, an isolated perfused mouse heart was subjected to 30 min of ischemia followed by 2 h of reperfusion. Experiments were terminated before ischemia (baseline), after ischemia, and at 30, 60, 90 and 120 min of reperfusion. At the end of each experiment, hearts were processed for the evaluation of apoptosis and DNA laddering. The in situ end labeling (ISEL) technique was used to detect apoptotic cardiomyocyte nuclei while DNA laddering was evaluated by subjecting the DNA obtained from the cardiomyocytes to 1.8% agarose gel electrophoresis followed by photographing under UV illumination. The results of our study revealed that apoptotic cells appear only after 60 min of reperfusion as demonstrated by the intense fluorescence of the immunostained genomic DNA when observed under fluorescence microscopy. None of the ischemic hearts showed any evidence of apoptosis. These results were corroborated with the findings of DNA fragmentation showing increased ladders of DNA bands in the same reperfused hearts representing integer multiples of the internucleosomal DNA length (about 180 bp). Since our previous studies showed a role of glutathione peroxidase (GSHPx) in apoptotic cell death, we performed identical experiments using isolated hearts from GSHPx-l knockout mice and transgenic mice overexpressing GSHPx-l. GSHPx-l knockout mice showed evidence of apoptotic cell death even after 30 min of reperfusion. Significant number of apoptotic cells were found in the cardiomyocytes as compared to non-transgenic control animals. To the contrary, very few apoptotic cells were found in the hearts of the transgenic mice overexpressing GSHPx-l. Hearts of GSHPx-l knockout mice were more susceptible to ischemia/reperfusion injury while transgenic mice overexpressing GSHPx- 1 were less susceptible to ischemia reperfusion injury compared to non-transgenic control animals. The results of this study clearly demonstrate a role of GSHPx in ischemia/reperfusion-induced apoptosis in mouse heart.
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  • 148
    ISSN: 1573-4919
    Schlagwort(e): MKP-1 ; Fas ligand ; Fas ; apoptosis ; prostate cancer
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Abstract Recent studies have suggested that MAP kinase phosphatase 1 (MKP-1) is overexpressed in prostate cancer. To evaluate the role of MKP-1 in regulating cell death and tumor growth in prostate cancer, MKP-1 was conditionally overexpressed in the human prostate cancer cell line DU145. Overexpression of MKP-1 in DU145 cells blocked activation of stress-activated protein kinase (SAPK/JNK). MKP-1 overexpression in DU-145 cells was also found to inhibit Fas ligand (FasL)-induced apoptosis, as well as block the activation of caspases by Fas engagement. In addition, MKP-1 blocked the activation of apoptosis by transfected MEKK-1 and ASK-1, presumably through its inhibition of the SAPK/JNK family of enzymes. MKP-1 blocked the ability of FasL to induce loss of mitochondrial transmembrane potential (Δγm), suggesting that MKP-1 acts upstream of mitochondrial pro-apoptotic events induced by FasL and that the SAPK/JNK pathway may form the signaling link between Fas receptor and mitochondrial dysfunction. Thus, MKP-1 overexpression in prostate cancer may play a role in promoting prostate carcinogenesis by inhibiting FasL-induced cell death.
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  • 149
    Digitale Medien
    Digitale Medien
    Springer
    Molecular and cellular biochemistry 199 (1999), S. 125-137 
    ISSN: 1573-4919
    Schlagwort(e): apoptosis ; ADP-ribosylation ; caspases ; PARP ; PARG
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Abstract Poly(ADP-ribosylation) is a post-translational modification playing a relevant role in DNA damage recovery, DNA replication and viral integration. Several reports also suggest a modulation of this process during cell death by apoptosis. The aim of this review is to discuss the possible involvement of poly(ADP-ribosylation) during apoptosis, by dealing with general considerations on apoptosis, and further examining the correlation between NAD consumption and cell death, the regulation of poly(ADP-ribose) metabolism in apoptotic cells, the effect of poly(ADP-ribose) polymerase inhibition on cell death occurrence and the use of enzyme cleavage as a marker of apoptosis. Finally, the future prospects of the research in this area will be addressed.
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  • 150
    ISSN: 1573-4919
    Schlagwort(e): DNA binding protein ; NAD metabolism ; cellular response to DNA damage ; γ-rays ; alkylating agents ; genomic instability ; apoptosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Abstract A dual approach to the study of poly (ADP-ribose)polymerase (PARP) in terms of its structure and function has been developed in our laboratory. Random mutagenesis of the DNA binding domain and catalytic domain of the human PARP, has allowed us to identify residues that are crucial for its enzymatic activity. In parallel PARP knock-out mice were generated by inactivation of both alleles by gene targeting. We showed that: (i) they are exquisitely sensitive to γ-irradiation, (ii) they died rapidly from acute radiation toxicity to the small intestine, (iii) they displayed a high genomic instability to γ-irradiation and MNU injection and, (iv) bone marrow cells rapidly underwent apoptosis following MNU treatment, demonstrating that PARP is a survival factor playing an essential and positive role during DNA damage recovery and survival.
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  • 151
    ISSN: 1573-4919
    Schlagwort(e): PARP ; poly(ADP-ribosyl)ation ; apoptosis ; DNA replication
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Abstract We have focused on the roles of PARP and poly(ADP-ribosyl)ation early in apoptosis, as well as during the early stages of differentiation-linked DNA replication. In both nuclear processes, a transient burst of PAR synthesis and PARP expression occurs early, prior to internucleosomal DNA cleavage before commitment to apoptosis as well as at the round of DNA replication prior to the onset of terminal differentiation. In intact human osteosarcoma cells undergoing spontaneous apoptosis, both PARP and PAR decreased after this early peak, concomitant with the inactivation and cleavage of PARP by caspase-3 and the onset of substantial DNA and nuclear fragmentation. Whereas 3T3-L1, osteosarcoma cells, and immortalized PARP +/+ fibroblasts exhibited this early burst of PAR synthesis during Fas-mediated apoptosis, neither PARP-depleted 3T3-L1 PARP-antisense cells nor PARP -/- fibroblasts showed this response. Consequently, whereas control cells progressed into apoptosis, as indicated by induction of caspase-3-like PARP-cleavage activity, PARP-antisense cells and PARP -/- fibroblasts did not, indicating a requirement for PARP and poly(ADP-ribosyl)ation of nuclear proteins at an early reversible stage of apoptosis. In parallel experiments, a transient increase in PARP expression and activity were also noted in 3T3-L1 preadipocytes 24 h after induction of differentiation, a stage at which ~95% of the cells were in S-phase, but not in PARP-depleted antisense cells, which were consequently unable to complete the round of DNA replication required for differentiation. PARP, a component of the multiprotein DNA replication complex (MRC) that catalyzes viral DNA replication in vitro, poly(ADP-ribosyl)ates 15 of ~40 MRC proteins, including DNA pol α, DNA topo I, and PCNA. Depletion of endogenous PARP by antisense RNA expression in 3T3-L1 cells results in MRCs devoid of any DNA pol α and DNA pol δ activities. Surprisingly, there was no new expression of PCNA and DNA pol α, as well as the transcription factor E2F-1 in PARP-antisense cells during entry into S-phase, suggesting that PARP may play a role in the expression of these proteins, perhaps by interacting with a site in the promoters for these genes.
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  • 152
    ISSN: 1573-4919
    Schlagwort(e): breast cancer cells ; anti-apoptotic genes ; apoptosis ; progesterone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Abstract Progesterone inhibits the proliferation of normal breast epithelial cells in vivo, as well as breast cancer cells in vitro. But the biologic mechanism of this inhibition remains to be determined. We explored the possibility that an antiproliferative activity of progesterone in breast cancer cell lines is due to its ability to induce apoptosis. Since p53, bcl-2 and survivin genetically control the apoptotic process, we investigated whether or not these genes could be involved in the progesterone-induced apoptosis. We found a maximal 90% inhibition of cell proliferation with T47-D breast cancer cells after exposure to 10 μM progesterone for 72 h. Control progesterone receptor negative MDA-231 cancer cells were unresponsive to 10 μM progesterone. The earliest sign of apoptosis is translocation of phosphatidylserine from the inner to the outer leaflet of the plasma membrane and can be monitored by the calcium-dependent binding of annexin V in conjunction with flow cytometry. After 24 h of exposure to 10 μM progesterone, cytofluorometric analysis of T47-D breast cancer cells indicated 43% were annexin V-positive and had undergone apoptosis and no cells showed signs of cellular necrosis (propidium iodide negative). After 72 h of exposure to 10 μM progesterone, 48% of the cells had undergone apoptosis and 40% were annexin V positive/propidium iodide positive indicating signs of necrosis. Control untreated cancer cells did not undergo apoptosis. Evidence proving apoptosis was also demonstrated by fragmentation of nuclear DNA into multiples of oligonucleosomal fragments. After 24 h of exposure of T47-D cells to either 1 or 10 μM progesterone, we observed a marked down-regulation of protooncogene bcl-2 protein and mRNA levels. mRNA levels of survivin and the metastatic variant CD44 v7-v10 were also downregulated. Progesterone increased p53 mRNA levels. These results demonstrate that progesterone at relative high physiological concentrations, but comparable to those seen in plasma during the third trimester of human pregnancy, exhibited a strong antiproliferative effect on breast cancer cells and induced apoptosis.
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  • 153
    Digitale Medien
    Digitale Medien
    Springer
    Molecular and cellular biochemistry 200 (1999), S. 51-57 
    ISSN: 1573-4919
    Schlagwort(e): smokeless tobacco ; apoptosis ; nitric oxide
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Abstract Smokeless tobacco usage is, a growing public health concern in the United States. Lesions of the oral cavity have been clearly linked to smokeless tobacco use. The objective of this study was to determine the biochemical effects of smokeless tobacco extract (STE) exposure upon hamster cheek pouch cell (HCPC-1) cultures. HCPC-1 cells were exposed to a 5 -fold dose-range of STE (0.5, 1.0 and 2.5%) over a time-course of 24-96 h. Following each exposure we measured various biochemical parameters of cell proliferation and cell death. Cell viability, cell cycle progression and S-phase DNA synthesis were measured as markers of cell proliferation. We measured lactate dehydrogenase leakage as a marker of cell membrane damage and cell death due to necrosis. No significant alterations were observed in cell cycle progression and cell proliferation as a result of exposure to STE. LDH measured colorimetrically indicated no significant effect with the lower doses (0.5, 1.0 and 2.5% STE). Apoptosis measured as the A0 peak and by the TUNEL procedure revealed that STE caused significant rates of apoptosis. Maximal apoptosis was noted between 48-96 h. In order to probe the mechanism further we measured the levels of nitrites as an indicator of nitric oxide (NO) in the media. NO levels were significantly elevated at the doses that caused an induction of apoptosis. The results from this study indicate that STE causes a dose-dependent induction of apoptosis and that this is mediated by nitric oxide.
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  • 154
    Digitale Medien
    Digitale Medien
    Springer
    Molecular and cellular biochemistry 193 (1999), S. 37-42 
    ISSN: 1573-4919
    Schlagwort(e): Rho ; GTPase ; toxins ; Clostridium ; signal transduction ; apoptosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Abstract The Rho family small GTPases are members of the Ras superfamily of small GTPases. Rho proteins were first determined to act as key regulators of many types of actin cytoskeletal-dependent cellular functions. Recent work by several investigators indicates that Rho GTPases are also critical modulators of several important intracellular and nuclear signal transduction pathways. Certain clostridial toxins and exoenzymes covalently modify, and thereby inactivate, specific types of Rho family GTPases. As such, these microbial enzymes have proven invaluable in helping to identify structural and functional attributes of Rho GTPases.
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  • 155
    ISSN: 1573-4919
    Schlagwort(e): nitrosourea ; chemotherapy ; anemia ; leukopenia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Abstract Most chemotherapy agents function by causing damage to the DNA of rapidly dividing cells, such as those in the bone marrow, leading to anemia and leukopenia during chemotherapy and the development of secondary leukemias in the years following recovery from the original disease. We created an animal model of nitrosourea-based chemotherapy using ethylnitrosourea (ENU) to investigate the effect of niacin deficiency on the side effects of chemotherapy. Weanling Long-Evans rats were fed diets containing various levels of niacin for a period of 4 weeks. ENU treatment started after 1 week of feeding and consisted of 12 doses delivered by gavage, every other day. Cancer incidence was also monitored in the following months. ENU treatment caused many of the acute symptoms seen in human chemotherapy patients, including anemia and neutropenia. Niacin deficiency (ND) had several interesting effects, alone and in combination with ENU. Niacin deficiency alone caused a modest anemia, while in combination with ENU it induced a severe anemia. Niacin deficiency alone caused a 4-fold increase in circulating neutrophil numbers, and this population was drastically reduced by ENU-treatment. In the long term, macin deficiency caused an increased incidence of cancer, especially chronic granulocytic leukemias.
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  • 156
    Digitale Medien
    Digitale Medien
    Springer
    Molecular and cellular biochemistry 193 (1999), S. 103-108 
    ISSN: 1573-4919
    Schlagwort(e): Poly(ADP-ribose) polymerase ; Drosophila melanogaster ; alternative splicing ; apoptosis ; DNA repair ; development
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Abstract Poly(ADP-ribose) polymerase (PARP) is conserved in eukaryotes. To analyze the function of PARP, we isolated and characterized the gene for PARP in Drosophila melanogaster. The PARP gene consisted of six translatable exons and spanned more than 50 kb. The DNA binding domain is encoded by exons 1-4. Although the consensus cleavage site of CED-3 like protease during apoptosis is conserved from human to Xenopus laevis PARPs, it is neither conserved in the corresponding region of Drosophila nor Sarcophaga peregrina. There are two cDNAs species in Drosophila. One cDNA could encode the full length PARP protein (PARP I), while the other is a truncated cDNA which could encode a partial-length PARP protein (PARP II), which lacks the automodification domain and is possibly produced by alternative splicing. The expression of these two forms of PARP in E. coli demonstrated that while PARP II has the catalytic NAD-binding domain and DNA-binding domain it is enzymatically inactive. On the other hand PARP I is active. A deletion mutant of PARP gene could grow to the end of embryogenesis but did not grow to the adult fly. These results suggest that the PARP gene plays an important function during the development of Drosophila.
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  • 157
    Digitale Medien
    Digitale Medien
    Springer
    Molecular and cellular biochemistry 193 (1999), S. 119-125 
    ISSN: 1573-4919
    Schlagwort(e): benzamides ; nicotinamides ; apoptosis ; inflammation ; NF-kB ; DNA repair
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Abstract Our laboratory has concentrated on the possible regulation the benzamides and nicotinamides may have on the processes of DNA repair and apoptosis. Recent reports [14-16] have suggested that both apoptosis and inflammation are regulated by the transcription factor NF-kB. We have initiated studies regarding the hypothesis that the benzamides and nicotinamides could inhibit the production of tumor necrosis factor alpha (TNFalpha) and the inflammatory response as well as induce apoptosis via inhibition of NF-kB. Our data have shown that nicotinamide and two N-substituted benzamides, metoclopramide (MCA) and 3-chloroprocainamide (3-CPA), gave dose dependent inhibition of lipopolysacharide induced TNFalpha in the mouse within the dose range of 10-500 mg/kg. Moreover, lung edema was prevented in the rat by 3 ï 50 mg/kg doses of 3-CPA or MCA, and 100-200 μM doses of MCA could also inhibit NF-kB in Hela cells. Taken together these data strongly support the notion that benzamides and nicotinamides have potent anti-inflammatory and antitumor properties, because their primary mechanism of action is regulated by inhibition at the gene transcription level of NF-kB, which in turn inhibits TNFalpha and induces apoptosis.
    Materialart: Digitale Medien
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  • 158
    ISSN: 1573-4919
    Schlagwort(e): antisense oligonucleotide ; apoptosis ; cAMP-dependent protein kinase ; cancer cells ; growth inhibition
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Abstract The enhanced expression of the RIα subunit of cyclic AMP-dependent protein kinase type 1 (PKA-I) has been correlated with cancer cell growth. We have investigated the effects of sequence-specific inhibition of RIα gene expression on the growth of MCF-7 human breast cancer cells. We report that RIα antisense treatment results in a reduction in RIα expression at both mRNA and protein levels and inhibition of cell growth. The growth inhibition was accompanied by changes in cell morphology, cleavage of poly(ADP-ribose) polymerase (PARP) and appearance of apoptotic nuclei. In addition, bcl-2 protein level was reduced and p53 expression increased in growth arrested cells. Interestingly, RIα antisense inhibited cell viability and induced apoptosis in the absence of p53, suggesting that these actions of RIα antisense are exerted independent of p53. In contrast, two- and four-base mismatched control oligonucleotides had no effect on either cell growth or morphology. These results demonstrate that the RIα antisense, which efficiently depletes the growth stimulatory molecule RIα, induces cell differentiation and apoptosis, providing a new approach to combat breast cancer cell growth.
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  • 159
    Digitale Medien
    Digitale Medien
    Springer
    Molecular and cellular biochemistry 197 (1999), S. 97-108 
    ISSN: 1573-4919
    Schlagwort(e): neutrophil ; PKC ; TNF-α ; apoptosis ; DNA fragmentation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Abstract In the present study we investigated the TNF-α induced signal transduction mechanism in human neutrophil. Exogenously added TNF-α affects both PKC activity and its translocation from cytosol to the membrane. Endogenous protein phosphorylation pattern is inhibited in TNF-α induced neutrophil in Ca-dependent and Ca-independent manner, including a major 47 and 66 kDa cytosolic proteins, which may be implicated in superoxide anion generation. However TNF-α dose dependently enhances the expression of ζ-PKC isotype but not the β-PKC. Morphology and cell cytotoxicity are studied in TNF-α treated neutrophil to understand the TNF-α induced cell death or apoptosis and these experiment is further confirmed by DNA fragmentation analysis. These results clearly demonstrate that TNF-α induces cellular death of human neutrophil at least in part by enhanced expression of Ca-independent ζ-PKC. These observations provide an insight towards understanding the function of ζ-PKC in apoptotic pathway.
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  • 160
    ISSN: 1573-4919
    Schlagwort(e): rotenone ; apoptosis ; oncogenes ; liver cancer
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Abstract Rotenone decreases the incidence of hepatocellular carcinoma and lowers rates of hepatocellular proliferation. In an effort to delineate mechanisms involved, the in vivo effect of rotenone on liver mitochondrial metabolism, apoptotic machinery as well as elements of the hepatic signal transduction pathways were investigated. Mitochondria from livers of male B6C3F1 mice fed a standard diet containing 600 ppm rotenone for 7 days were uncoupled or inhibited when succinate or glutamate plus malate were used as the substrate, respectively. These livers also showed a significant increase in apoptosis compared with control livers. Furthermore, rotenone increased the expression of c-myc mRNA to 5-fold of control values within 3 days, an effect which was still observed (3-fold) after 7 days. Levels of p53 mRNA were also increased 3-fold after 1 day, but declined to control levels by 7 days. Rotenone also caused a transient, yet marked increase in liver particulate glyceraldehyde phosphate dehydrogenase (GAPDH) protein expression, while it did not alter the expression of the cytosolic form of the enzyme. Conversely, mRNA of the proto-oncogene H-ras showed a decline of 35% after 3 days of rotenone treatment, and remained diminished for the duration of the experiment. These data suggest that rotenone may act as an anticancer agent by diminishing mitochondrial bioenergetics which prevents basal hepatocyte proliferation and lowers the threshold for liver cells with DNA damage to undergo apoptosis.
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  • 161
    ISSN: 1573-4943
    Schlagwort(e): Two-dimensional electrophoresis ; MALDI-MS ; apoptosis ; RNA polymerase B transcription factor 3
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Apoptosis or programmed cell death is essential in the process of controlling lymphocyte growth and selection. We identified RNA polymerase B transcription factor 3 (BTF3), which is associated with anti-IgM antibody-mediated apoptosis, using a subclone of the human Burkitt lymphoma cell line BL60. To identify the transcription factor BTF3, which is expressed only in minor amounts, we used preparative high-resolution two-dimensional gel electrophoresis (2DE) employing carrier ampholytes for isoelectric focusing. Comparison of the 2DE protein patterns from apoptotic and nonapoptotic cells showed BTF3 as a predominantly altered protein spot. The characterization of the differentially expressed transcription factor and 13 marker proteins described in this study were performed by internal Edman microsequencing and/or by peptide mass fingerprinting using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). The proteome analysis was significantly improved by performing the newly developed preparative high-resolution two-dimensional gels employing high protein concentrations.
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  • 162
    ISSN: 1432-5233
    Schlagwort(e): Key words Mitochondrial DNA ; Genetics ; Maternally inherited diabetes mellitus ; Deafness ; np 3243 mutation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Mitochondrial DNA (mtDNA) gene defects may play a role in the development of maternally inherited diabetes mellitus and deafness (MIDD). A family from Southern Italy who showed maternal transmission of type 2 diabetes mellitus with three individuals affected is described. A 10.4 kb deletion and mutations at nucleotide positions (np) 3243, 7445 and 11778 in the mtDNA of six relatives were sought. The mitochondrial np 3243 mutation of the tRNA Leu (UUR) gene was identified in a boy affected by optic atrophy and mental retardation, as well as in his diabetic mother. No other mutations or deletions were found. Our study points out the variable phenotypic expression of the np 3243 mtDNA mutation. This may suggest the presence of other mitochondrial or nuclear mutations required to modulate the phenotype. A clinical and metabolic follow-up of all family members was necessary to understand the role of the np 3243 mutation, especially in one child affected by optic atrophy and mental retardation. Further studies will be aimed at investigating the prevalence of mutations and deletions of mtDNA in type 2 diabetes mellitus.
    Materialart: Digitale Medien
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  • 163
    ISSN: 1432-2242
    Schlagwort(e): Key words Passiflora ; Self-incompatibility ; Genetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract  The self-incompatibility in yellow passion fruit was previously described as homomorphic sporophytic with monofactorial inheritance. Five progenies were obtained by bud-selfing. The plants of these progenies were selfed, reciprocally crossed within each progeny and crossed with known incompatible phenotypes to identify their phenotypic group. Fruit set was evaluated at the 7th day after pollination. Two progenies consisted of two self-incompatible groups, the other three formed three suck groups. The groups were identified as S1, S2, S3, S4, S5 and S6. The results provide evidence that the self-incompatibility of passion fruit is controlled by two loci, the S-gene and another, whose expression needs to be investigated.
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  • 164
    ISSN: 1432-2242
    Schlagwort(e): Key words Simple sequence repeat (SSR) ; Microsatellites ; Molecular markers ; Genetics ; Fingerprinting
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract  We report the sequences of 17 primer pairs of microsatellite loci, which we have cloned and sequenced from two genomic libraries of peach [Prunus persica (L) Batsch] ‘Redhaven’, enriched for AC/GT and AG/CT repeats respectively. For ten of these microsatellite loci we were able to demonstrate Mendelian inheritance in a segregating back-cross population; the remainder did not segregate. The polymorphism of the microsatellites was evaluated in a panel of ten peach genotypes, including true-to-type peaches, nectarines and one canning-peach. Fifteen microsatellites (88%) were polymorphic showing 2–4 alleles each. The mean heterozygosity, averaged over all loci, was 0.32 and significantly higher than that reported in the literature for isozymes and molecular markers, such as RFLPs and RAPDs. We have also assayed the cross-species transportability and found that ten microsatellite (59%) gave apparently correct amplification in all Prunus species surveyed, namely P. domestica (European plum), P. salicina (Japanese plum), P. armeniaca (apricot), P. dulcis (almond), P. persica var. vulgaris (peach), P. persica var. laevis (nectarine), P. avium (sweet cherry) and P. cerasus (sour cherry), with three of them also being amplified in Malus (apple). The remaining microsatellites gave less-extensive amplification. Because of their appreciable polymorphism and wide cross-species transportability, most of these new markers can be integrated into the linkage maps which are currently being constructed in peach, as well as in other stone fruit crops, such as almond, apricot, cherry and plum.
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  • 165
    Digitale Medien
    Digitale Medien
    Springer
    Theoretical and applied genetics 99 (1999), S. 800-810 
    ISSN: 1432-2242
    Schlagwort(e): Key words Almond ; Compatibility ; Genetics ; Prunus dulcis ; Ribonucleases
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract  Six almond progenies, each the product of a cross between a self-compatible and a self-incompatible parent, were analysed for stylar ribonucleases. Proteins were extracted and separated using non-equilibrium pH gradient electrofocusing (NEPHGE), and the gels were stained for ribonuclease activity. Most seedlings showed either two principal bands, interpreted as corresponding to two incompatibility alleles, or a single band. The seedlings were also bagged in the field at flowering time to determine fruit set after selfing, and some were also examined for the growth of pollen-tubes in selfed styles using UV fluorescence microscopy. With very few exceptions, those seedlings showing single-banded zymograms were found to be self-compatible according to field and microscope studies, and those with two bands were found to be self-incompatible. We conclude that the allele for self-compatibility in almond does not code for ribonuclease activity and that the ribonuclease isoenzyme assay is a convenient technique for predicting self-compatibility in segregating progenies. A novel band in two derivatives of ’Ferrastar’ was ascribed to a new incompatibility allele, S 10 .
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  • 166
    Digitale Medien
    Digitale Medien
    Springer
    Behavioral ecology and sociobiology 46 (1999), S. 171-179 
    ISSN: 1432-0762
    Schlagwort(e): Key words Honeybee ; Apis mellifera ; Division of labor ; Genetics ; Pollen foraging
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract  A fundamental requirement of task regulation in social groups is that it must allow colony flexibility. We tested assumptions of three task regulation models for how honeybee colonies respond to graded changes in need for a specific task, pollen foraging. We gradually changed colony pollen stores and measured behavioral and genotypic changes in the foraging population. Colonies did not respond in a graded manner, but in six of seven cases showed a stepwise change in foraging activity as pollen storage levels moved beyond a set point. Changes in colony performance resulted from changes in recruitment of new foragers to pollen collection, rather than from changes in individual foraging effort. Where we were able to track genotypic variation, increases in pollen foraging were accompanied by a corresponding increase in the genotypic diversity of pollen foragers. Our data support previous findings that genotypic variation plays an important role in task regulation. However, the stepwise change in colony behavior suggests that colony foraging flexibility is best explained by an integrated model incorporating genotypic variation in task choice, but in which colony response is amplified by social interactions.
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  • 167
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 296 (1999), S. 511-516 
    ISSN: 1432-0878
    Schlagwort(e): Key words Molecular biology ; Cell biology ; Bioassay ; Analytical chemistry ; Biochemistry ; Diagnosis ; Therapy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract  Significant amounts of endogenous biotin were detected by avidin-peroxidase in fixed rat kidney, liver, and brain. The staining was indistinguishable from the true signals of immunoreactivity and could not be consistently blocked by pretreatment with avidin. The finding that certain neurons in the hippocampus contain more biotin than neurons in other areas of the brain suggests that biotin might have novel functions in the brain other than its well-known role as cofactor of carboxylases. Critical examination of published immunohistochemical localization studies on rat kidney strongly suggests that many false-positive results have been considered as true signals. Interference of endogenous biotin in any study using avidin-biotin technology must be considered if biological tissues are involved. The published data obtained by this method should therefore be reevaluated. Furthermore, appropriate controls, blockers and caution in interpreting results must be exercised, not only in immunohistochemistry but also in any applications of avidin-biotin technology.
    Materialart: Digitale Medien
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  • 168
    ISSN: 1573-0646
    Schlagwort(e): chemotherapy ; platinum (IV) analogues ; cisplatin resistance ; pharmacodynamics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Abstract Ormaplatin (NSC 363812, tetraplatin) is a stable platinum (IV) analog which has exhibited activity against cisplatin-resistant cell lines. A phase I trial of ormaplatin administered as a 1-h infusion every 4 weeks was performed. Forty-one patients received 101 cycles of drug over the dose range 4–128 mg/m2. The dose-limiting toxicity was reversible thrombocytopenia and granulocytopenia. Minimal myelosuppression was observed at dose levels ≤ 78 mg/m2, while grade 3 or 4 myelosuppression (thrombocytopenia and/or granulocytopenia) was seen in 4/8 patients at 98 mg/m2 and 4/5 patients at 123 mg/m2. Nausea and vomiting was observed at all dose levels but was controlled with antiemetic premedication. Neurotoxicity was observed in 5/41 patients and the incidence appeared related to cumulative dose rather than to dose level or drug clearance. Platinum was measured by furnace atomic absorption spectrophotometry. Ormaplatin-derived plasma ultrafilterable platinum (UF-Pt) exhibited linear pharmacokinetics over the dose range studied. The mean total body clearance of UF-Pt was 135 ml/min/m2 and the mean elimination half-life (t1/2β) was 13.6 h. Ormaplatin exhibited a high degree of protein binding, with more than 70% of platinum protein bound by the end of the infusion. Urinary excretion of platinum accounted for 37% of the total dose of ormaplatin in 24 hours. A phase II dose of 98 mg/m2 is recommended for testing in a patient population with cisplatin-refractory disease.
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  • 169
    Digitale Medien
    Digitale Medien
    Springer
    Investigational new drugs 17 (1999), S. 227-240 
    ISSN: 1573-0646
    Schlagwort(e): apoptosis ; protein kinase C ; sphingoid bases ; safingol ; diglyceride ; bryostatin 1 ; staurosporine ; 7-hydroxy staurosporine (UCN-01) ; 4′-N-benzoyl staurosporine (CGP-41251) ; calphostin C (UCN-1028c)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Abstract Neoplastic cell survival is governed by a balance between pro-apoptotic and anti-apoptotic signals. Noteworthy among several anti-apoptotic signaling elements is the protein kinase C (PKC) isoenzyme family, which mediates a central cytoprotective effect in the regulation of cell survival. Activation of PKC, and subsequent recruitment of numerous downstream elements such as the mitogen-activated protein kinase (MAPK) cascade, opposes initiation of the apoptotic cell death program by diverse cytotoxic stimuli. The understanding that the lethal actions of numerous antineoplastic agents are, in many instances, antagonized by cytoprotective signaling systems has been an important stimulus for the development of novel antineoplastic strategies. In this regard, inhibition of PKC, which has been shown to initiate apoptosis in a variety of malignant cell types, has recently been the focus of intense interest. Furthermore, there is accumulating evidence that selective targeting of PKC may prove useful in improving the therapeutic efficacy of established antineoplastic agents. Such chemosensitizing strategies can involve either (a) direct inhibition of PKC (e.g., following acute treatment with relatively specific inhibitors such as the synthetic sphingoid base analog safingol, or the novel staurosporine derivatives UCN-01 and CGP-41251) or (b) down-regulation (e.g., following chronic treatment with the non-tumor-promoting PKC activator bryostatin 1). In preclinical model systems, suppression of the cytoprotective function(s) of PKC potentiates the activity of cytotoxic agents (e.g., cytarabine) as well as ionizing radiation, and efforts to translate these findings into the clinical arena in humans are currently underway. Although the PKC-driven cytoprotective signaling systems affected by these treatments have not been definitively characterized, interference with PKC activity has been associated with loss of the mitogen-activated protein kinase (MAPK) response. Accordingly, recent pre-clinical studies have demonstrated that pharmacological disruption of the primary MEK-ERK module can mimic the chemopotentiating and radiopotentiating actions of PKC inhibition and/or down-regulation.
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  • 170
    Digitale Medien
    Digitale Medien
    Springer
    Investigational new drugs 17 (1999), S. 313-320 
    ISSN: 1573-0646
    Schlagwort(e): cell cycle ; flavopiridol ; cyclin-dependent kinases ; cyclin D1 ; flavonoids ; chemotherapy ; protein kinases ; signal transduction ; clinical trials
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Abstract The discovery and cloning of the cyclin-dependent kinases (cdks), main regulators of cell cycle progression, allowed several investigators to design novel modulators of cdk activity. Flavopiridol (HMR 1275, L86-8275), a flavonoid derived from an indigenous plant from India, demonstrated potent and specific in vitro inhibition of all cdks tested (cdks 1, 2, 4 and 7) with clear block in cell cycle progression at the G1/S and G2/M boundaries. Moreover, preclinical studies demonstrated the capacity of flavopiridol to induce programmed cell death, promote differentiation, inhibit angiogenic processes and modulate transcriptional events. The relationship between the latter effects and cdk inhibition is still unclear. Initial testing in early clinical human trials with infusional flavopiridol showed activity in some patients with non-Hodgkin's lymphoma, renal, prostate, colon and gastric carcinomas. Main side effects were secretory diarrhea and a pro-inflammatory syndrome associated with hypotension. Biologically active plasma concentrations of flavopiridol (∼300–500 nM) are easily achievable in patients receiving infusional flavopiridol. Phase 2 trials with infusional flavopiridol in several tumor types, other schedules and combination with standard chemotherapies are being assessed. In conclusion, flavopiridol is the first cdk inhibitor to be tested in clinical trials. Although important questions remain to be answered, this positive experience will stimulate the development of novel cdk modulators for cancer therapy.
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  • 171
    ISSN: 1573-0646
    Schlagwort(e): UCN-01 ; IL-2 receptor ; Fas ; Fas-ligand ; apoptosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Abstract 7-hydroxystaurosporine (UCN-01) is a new anticancer agentwhich exerts an inhibitory effect on cell cycle check points andis currently under phase I clinical trials in US and Japan.Preliminary clinical data indicated that UCN-01 remained inplasma at high concentrations for long periods of time. Thisunavoidable high plasma drug exposure is likely to lead tohematological toxicities in patients. In the present study,cultured human peripheral blood lymphocytes (PBLs) were used toevaluate the possible hematological toxicities of UCN-01treatment. UCN-01 induces apoptosis, and the induction ofapoptosis-related surface markers were also examined toinvestigate the involvement of these molecules in UCN-01-inducedapoptosis in PBLs. in vitroviability of PBLs wasdecreased by high dose of UCN-01 (25 μM, 3-day exposure). Thiseffect of UCN-01 was significantly suppressed by the presence ofhuman serum, suggesting that some specific inhibitory factor(s)in human serum may antagonize the lympholytic effect of UCN-01.The percentage of annexin V-positive PI-negative cells increasedwith exposure to UCN-01 in a time- and dose-dependent manner; byup to 30.3% after exposure to 25 μM UCN-01 for 3 days.At the same time, the expression of both interleukin-2 receptor(IL-2R, CD25) and Fas (CD95), analyzed by flow cytometry, wasinduced. Con A-stimulated PBLs were more sensitive toUCN-01-induced apoptosis than non-stimulated lymphocytes andUCN-01 increased the sFas-L released into culture medium from conA-stimulated PBLs. Therefore, lymphocyte depletion mediated byactivation-induced apoptosis is likely to occur in patientstreated with UCN-01 at high doses.
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  • 172
    ISSN: 1573-0778
    Schlagwort(e): apoptosis ; Bcl-2 ; fixed-bed ; hollow fibre ; hybridoma ; perfusion ; protein-free medium
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Abstract Apoptosis is an active, genetically determined death mechanism which can be induced by a wide range of physiological factors and by mild stress. It is the predominant form of cell death during the production of antibodies from murine hybridoma cell lines. A number of studies have now demonstrated that the suppression of this death pathway, by means of over-expression of survival genes such as bcl-2, results in improved cellular robustness and antibody productivity during batch culture. In the present study, the influence of bcl-2 expression on hybridoma productivity in two high density perfusion bioreactor systems was investigated. In the first system, a fixed-bed reactor, the DNA content in the spent medium was 25% higher in the control (TB/C3-pEF) culture than that found in the bcl-2 transfected (TB/C3-bcl2) cultures at all perfusion rates. This is indicative of a higher level of cell death in the control cell line. The average antibody concentration for the TB/C3-pEF cell line was 14.9 mg L-1 at perfusion rates of 2.6 and 5.2 d-1. However, for the TB/C3-bcl2 cell line it was 33 mg L-1 at dilution rates of 2 and 4 d-1. A substantial increase in antibody concentration was also found in the Integra Tecnomouse hollow fibre reactor. The antibody titre in the TB/C3-bcl2 cassette was nearly 100% higher than that in the TB/C3-pEF cassette during the cultivation period which lasted 6 weeks. Clearly, these results demonstrate the positive impact of bcl-2 over-expression on production of antibody in hybridoma perfusion cultures.
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  • 173
    ISSN: 1573-0778
    Schlagwort(e): antibody productivity ; apoptosis ; BAG-1 ; Bcl-2 ; cell survival ; hybridoma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Abstract Human bcl-2 and bag-1 DNA were introduced into mouse hybridoma 2E3- O cells and expressed. The expression of bcl-2 in BCMGneo-bcl2 transfectants was confirmed by ELISA and that of bag-1 in pZeo-bag1 was confirmed by western blotting. In batch cultures, the over-expression of bcl-2 prolonged the culture period by 2 days and co-expression of bcl-2 and bag-1 prolonged the culture period by 3 days. The delayed increase in the dead cell number in culture of the bcl-2 and bag-1 cotransfectant indicated the additional antiapoptosis effect of bcl-2 and bag-1 cotransfection in comparison with the bcl-2 only transfection. The bcl-2 transfectants (2E3O-Bcl2) produced antibody twofold per batch culture in comparison with 2E3-O cells transfected with BCMGSneo (2E3O-Mock). Enhancement of this MoAb production was due to the improved survival of the cells and was not due to stimulation of antibody production rate per cell by Bcl-2 expression. And the bcl-2 and bag-1 co-transfectant (2E3O-Bcl2-BAG1) produced antibody approximately fourfold of 2E3O-Mock per batch culture. Enhancement of this MoAb production was due to the improved survival of the cells and was partly due to stimulation of MoAb production rate per cell in the non-growing phase by the cotransfection. The method to engineer hybridoma cells genetically with bcl-2 and bag-1 for increasing viability and productivity would be widely applied for improving antibody productivity of hybridoma cultures.
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  • 174
    ISSN: 1573-0778
    Schlagwort(e): annexin V ; Apo-2 ligand ; apoptosis ; Cytostar-T® scintillating microplates ; flow cytometry ; lymphotoxin (LT)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Abstract The translocation of phospholipids across the plasma membrane has been widely documented as one of the earliest measurable biochemical events of apoptosis. Using fluorescently labelled annexin V, which preferentially binds phosphatidylserine (PS) in the presence of Ca2+, the externalization of PS can be measured and apoptosis quantified using flow cytometry. Conventional detection methods utilizing annexin V, while faster than in situ DNA end-labelling or DNA laddering, require extensive sample preparation which may compromise samples and makes rapid, high volume screening prohibitive. This paper describes a novel assay for the measurement of apoptosis based upon binding of radiolabelled annexin V to apoptotic cells attached to the growth surface of a 96-well scintillating microplate (Cytostar-T®). We compared measurements of apoptosis made by flow cytometry to those obtained with the scintillating microplate in three model systems, treatment of: mouse connective tissue (L-M) cells with lymphotoxin (LT), human lung carcinoma (H460) cells with Apo-2 ligand and human umbilical vein endothelial (HUVE) cells with staurosporine. In this assay, we compare both direct and indirect labelling methods by utilizing either iodinated annexin V or biotinylated annexin V/[35S] streptavidin to radiolabel apoptotic cells. The signal detected is a direct consequence of the binding of annexin V to externalized PS on apoptotic cells and the proximity of the label to the base of the plate. Using this method, separation of bound and unbound radiolabel signal occurs directly within the well resulting in a sensitive assay that requires minimal manipulation and can accomodate a large number of samples.
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  • 175
    Digitale Medien
    Digitale Medien
    Springer
    Cardiovascular drugs and therapy 13 (1999), S. 289-294 
    ISSN: 1573-7241
    Schlagwort(e): heart failure ; apoptosis ; protein kinases ; caspases ; DNA damage ; cardiomyocytes ; β-blocks
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Apoptosis as defined by contemporary science describes a form of cell death that involves discrete genetic and molecular programs, de novo protein expression and unique cellular phenotype. Evidence for the existence of apoptosis in the human heart has been reported in various cardiac diseases, including ischemic and non-ischemic heart failure, myocardial infarction and arrhythmias. Among the most potent stimuli that elicit cardiomyocyte apoptosis are: oxygen radicals (including NO), cytokines, (FAS/TNFα family of cytokines) and growth factors/energy deprivation. Several complex signal transduction pathways have been implicated in execution of cardiomyocyte apoptosis, including: Fas/TNFα receptors signaling, stress or mitogen activated protein kinases (SAPK/MAPK), sphingolipids metabolites (ceramide), G-protein coupled receptor (GPCR) signaling (Gαi, Gαq) and NFkB activation. Apoptosis of cardiac myocytes may contribute to progressive pump-failure, arrhythmias and cardiac remodeling. The recognition of numerous molecular targets associated with cardiomyocyte apoptosis that are amenable for pharmacologic manipulation, may provide novel therapeutic strategies for diverse cardiac ailments, as recently suggested by pharmacologic studies in experimental animals.
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  • 176
    ISSN: 1573-7373
    Schlagwort(e): apoptosis ; cell death ; C6 glioma ; nerve growth factor
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Nerve growth factor (NGF) plays an important physiological role in differentiation and survival of various types of neurons. Glial cells and glial tumor cells synthesize multiple neurotrophic factors including NGF and secrete them into the surrounding environment; however, the mechanisms of NGF and the significance of NGF receptors have not been studied in detail. The C6 glioma cell line can synthesize NGF, respond to exogenous application of NGF and stimulate the expression of NGF receptor in an autocrine manner. In order to determine the significance of such an NGF autocrine system, the effects of exposure to exogenous NGF and deprivation of endogenous NGF were examined in a C6 glioma cell line in vitro. Exogenous NGF significantly inhibited maintenance of the cell number and thymidine incorporation. Morphological changes, including the formation of growth cones, outgrowth of processes and cellular hypertrophy, were observed, concurrently, indicating that exogenous NGF stimulated differentiation and thereby inhibited proliferation of the cells. Deprivation of endogenous NGF with anti-NGF antibody elicited a rapid decrease in cell number and thymidine incorporation, and led almost all of the cells to death within 8 days. The protein synthesis inhibitor, cycloheximide, strongly inhibited the death of NGF-deprived cells, suggesting the involvement of an active process requiring synthesis of suicide proteins. These findings imply that the NGF autocrine system plays a significant role in regulating the differentiation and survival of C6 glioma cells, similarly to neuronal cells.
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  • 177
    Digitale Medien
    Digitale Medien
    Springer
    Journal of neuro-oncology 41 (1999), S. 235-246 
    ISSN: 1573-7373
    Schlagwort(e): brain tumor ; intra-arterial administration ; chemotherapy ; drug delivery ; drug streaming
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The influences of the flow rate on the concentration and distribution of drug in the rat brains and brain tumors after intra-arterial (intra-carotid) administration of [3H]SarCNU (sarcosinamide chloroethyl-1-nitrosourea) were examined. Results obtained at three flow rates via intra-carotid route were compared to those obtained with intravenous administrations. Adult female Wistar rats bearing C6 brain tumor were randomized into four-groups. Groups 1 (G.1) to 3 (G.3) received intra-arterial injection and Group 4 (G.4) received intravenous administration of [3H]SarCNU. G.1 (slow infusion rate) was administered 1 ml of [3H]SarCNU solution over 60 min (0.017 ml/min), Group 2 (G.2; medium infusion rate): 0.2 ml over 5 min (0.04 ml/min), G.3 (fast infusion rate): 1 ml over 5 min (0.2 ml/min), and G.4 (intravenous infusion): 1 ml intravenously over 5 min. Quantitative autoradiographic method was used to measure the concentration and the distribution of [3H]SarCNU in the brain and the brain tumors. The tissue uptake constant of SarCNU in both viable (tumor tissue excluding necrosis) and peak regions (the area of tumor containing top 20% of the tracer concentration) of the intra-arterial injection groups were significantly higher (p〈0.0001) than those in the intravenous group. The mean concentrations of the viable tumor in the intra-arterial groups were 2.92 (G.1), 16.06 (G.2), and 20.8 (G.3) times higher than those of intravenous group. Between the intra-arterial groups, the mean concentration in the viable tumors of G.1 (slow flow rate) was significantly (p〈0.0001) lower than in G.2 and G.3. However, there was no significant difference between G.2 and G.3. In three intra-arterial groups the mean concentration delivery ratios of the brain tumors were high and ranged from 3.07 (G.3) to 3.87 (G.2), but there was no significant difference between them. Only G.4, intravenous group, showed significantly (p〈0.005) lower concentration delivery ratio, 1.26. These results suggest that higher infusion rate in the intra-arterial chemotherapy could have an effect not only on the streaming phenomenon which results in the brain toxicities, but also on the increase in the concentration and the sufficient distribution of a drug in tumors. By finding chemotherapeutic agents to which tumors show high sensitivity and using intra-arterial administration of these agents at more effective flow rate, better clinical results could be achieved in the treatment of patients with malignant brain tumors.
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  • 178
    ISSN: 1573-7373
    Schlagwort(e): glioma ; chemotherapy ; cisplatin ; amifostine ; DNA adducts
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The chemoprotective effect of amifostine (WR2721) was studied in a BDIX rat model with intracerebral BT4C glioma implants. Twenty-one rats were given cisplatin 5 mg/kg i.p., 21 were given amifostine 200 mg/kg i.p.+cisplatin 5 mg/kg i.p. Ten rats served as untreated controls. An immunohistochemical method for analysis of cisplatin–DNA adducts was used to elucidate the adduct formation in tumor, normal brain and kidney. Tumor volume and serum creatinine level were analysed 10 days after treatment. In animals pretreated with amifostine there was a delayed adduct formation rate in the normal brain, and in the kidney cortex the number of tubular cells with extremely high adduct level was reduced. No difference in adduct formation was seen in tumors. Tumor volume was significantly larger following amifostine+cisplatin (66% of controls) compared to cisplatin alone (38% of controls). Weight loss was, however, severe in rats given cisplatin alone. In the tumor growth study only 3 out of 11 rats treated with cisplatin 5 mg/kg alone survived until time of sacrifice at 10 days, whereas all those pretreated with amifostine survived. Mean serum creatinine was 48 µmol/l (controls), 146 µmol/l (cisplatin) and 59 µmol/l (amifostine+cisplatin). A marked reduction of histopathological renal changes was found when amifostine was added. Amifostine thus significantly reduced general and renal toxicity of cisplatin. The tumor growth retardation was stronger when cisplatin was given alone but this is probably related to general toxicity and malnutrition indirectly supported by the fact that amifostine did not significantly reduce cisplatin–DNA adduct formation in tumors. The results of the present study suggest that amifostine may have a role in increasing the therapeutic ratio of cisplatin, also in the treatment of malignant glioma.
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  • 179
    ISSN: 1573-7373
    Schlagwort(e): malignant glioma ; chemotherapy ; anthracyclines ; KRN8602(MX2) ; phase II study
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract KRN8602(MX2) is a newly developed morpholino-anthracycline that has been found to cross the blood–brain barrier and be distributed in brain tissue after intravenous administration and to be effective against human glioma cells and the intracerebrally transplanted tumors in vivo. In order to confirm these promising preclinical observations clinically, we performed a phase II trial of KRN8602 in patients with recurrent malignant glioma. The 44 patients enrolled received at least 2 cycles of KRN8602 35 mg/m2/day at 3–4 week intervals by intravenous bolus. Of the 44 patients, 37 could be evaluated for response, and 39 for toxicity. One patient with anaplastic astrocytoma had a complete response (1/37, 3%), and 2 patients with anaplastic astrocytoma and 1 with brain stem glioma had a partial response (3/37, 8%). The overall response rate was 11% (4/37). All patients who responded had received prior chemotherapy that included nitrosoureas. No response was observed in the patients with glioblastoma. Myelosuppression was moderately severe, with 72% of patients developing grade 3 or 4 leukopenia. Severe nausea/vomiting was observed in 31% of the patients. No severe cardiotoxicity was observed. The results indicate that KRN8602 has modest activity against recurrent malignant glioma with relatively severe, but manageable toxicity. It seems to be worthwhile to further assess the efficacy and toxicity of KRN8602 against malignant glioma, which is generally less sensitive to chemotherapy.
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  • 180
    ISSN: 1573-7373
    Schlagwort(e): anaplastic oligodendroglioma ; surgery ; radiotherapy ; chemotherapy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Purpose: To investigate feasibility, toxicity and antitumor activity of combined surgery, postoperative radiation therapy (RT) and adjuvant chemotherapy (CHT) in adult patients with pure anaplastic oligodendroglioma (PAO) or mixed anaplastic oligoastrocytoma (MAO). Methods: Between January 1988, and June 1993, 23 patients entered into a phase II study. After surgery, post-operative RT was administered with 60 Gy in 30 daily fractions in 30 treatment days in 6 weeks. Two weeks after RT, adjuvant ‘modified’ PCV (mPCV) (Procarbazine, 60 mg/m2, days 1–14; CCNU, 100 mg/m2, day 1; and vincristine, 1.4 mg/m2 (max. 2 mg), days 1 and 8) was administered every six weeks up to six cycles or until progression occurred. Results: Median survival time is not attained yet, while 1–5 year survival rates are 100%, 100%, 78%, 61%, and 52%, respectively. Median time to tumor progression is not attained yet, while 1–5 year progression-free survival rates are 100%, 100%, 70%, 52%, and 52%, respectively. On univariate analysis of potential prognostic factors, sex, tumor location (frontal versus other), and histology (pure versus mixed anaplastic oligodendroglioma) were not found to influence survival. Age of 〈50 years carried improved prognosis as well as Karnofsky performance status (KPS) 90–100 when compared to KPS of 70–80. Patients having tumors ≤4 cm did better than those with tumors 〉4 cm as well as those with total tumor resection when compared to those with subtotal tumor resection or biopsy only. Acute high-grade (≥3) CHT-related toxicity was mainly hematological with only 3 (13%) patients experiencing acute grade 4 toxicity. Conclusions: Combined treatment modality consisting of surgery, postoperative high-dose RT and mPCV chemotherapy for patients with anaplastic oligodendroglioma was effective with acceptable toxicity. Further studies are needed with more patients and longer follow-up to verify these results in this rare disease.
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  • 181
    ISSN: 1573-7373
    Schlagwort(e): glutamate ; glioblastoma ; apoptosis ; Bcl-2
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Glutamate has been shown to function as a toxic agent in neuronal and glial cells, as well as an excitatory neurotransmitter throughout the central nervous system. In the present study, we examined the effect of increasing glutamate concentration on the induction of apoptosis in the two human glioblastoma cell lines GB-4 and GB-12. Glutamate exposure caused cell death of GB-4 and GB-12 in a dose-dependent manner. The cells were found to die via apoptosis in response to glutamate based on the following criteria: propidium iodide (PI) staining, H–E staining, electron microscopic analysis, and the TdT-mediated dUTP-biotin nick end labeling (TUNEL) method. The glutamate-induced apoptosis appears to involve the modulation of Bcl-2 family gene products such as Bcl-2, Bcl-xL, and Bax-α. Both Bcl-2 and Bcl-xL were down-regulated by glutamate at 24 h and further at 48 h. The apoptosis-promoting product p21 Bax-α was also down-regulated in GB-12 but slightly up-regulated in GB-4, accompanied by generation of variant form of p18 Bax-α in both cell lines. These findings suggest that glutamate toxicity results in cellular death via an apoptotic mechanism which appears to involve the Bcl-2/Bax-α molecular complex.
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  • 182
    ISSN: 1573-7373
    Schlagwort(e): brain tumor ; chemotherapy ; stem cell rescue ; medulloblastoma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract High dose chemotherapy (HDCT) with autologous (bone marrow or peripheral blood) stem cell rescue (ASCR) has had success in the treatment of some malignant pediatric brain tumors. We report a series of adults enrolled in one of three HDCT and ASCR protocols for malignant primary brain tumors. Overall toxic mortality was 18%; chemotherapy regimen, tumor type, and prior treatment did not predict transplant-related mortality. Patients over the age of 30 had a higher rate of toxic mortality. Patients with recurrent medulloblastoma had a significant improvement in long-term survival (median: 34 months) as compared with historical reports; two patients with glioblastoma survive beyond four years without progression, but overall, a significant improvement in long-term survival could not be demonstrated for malignant gliomas.
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  • 183
    Digitale Medien
    Digitale Medien
    Springer
    Journal of neuro-oncology 45 (1999), S. 37-46 
    ISSN: 1573-7373
    Schlagwort(e): topoisomerase ; drug resistance ; chemotherapy ; glioma ; phosphorylation ; MRP
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The efficacy of the epipodophyllotoxins VP-16 and VM-26 is limited by the occurrence of drug resistance in the tumor cell population. Cellular insensitivity to drugs that stabilize the cleavable complex is frequently expressed as multidrug resistance (MDR). In some cell lines, overexpression of MDR-1/P-glycoprotein or the multidrug resistance associated protein (MRP) has been demonstrated and implicated as the mechanism of resistance. Typically, these cells have reduced drug accumulation, secondary to increased drug efflux. In other cell lines, an atypical MDR phenotype has been identified, with the predominant mechanism of resistance shown to be qualitative and/or quantitative changes in the levels and activity of topoisomerase II. For VP-16, increased expression of MDR-1 or MRP and alterations in topoisomerase II α have been shown to confer tolerance. To further understand resistance to VP-16, T98G-VP(1000) was initially isolated as a single clone from parental cell, T98G, by exposure to VP-16. Subsequently, a population of cells from this subline was exposed to three-fold higher drug concentration allowing stable sublines to be established at higher extracellular drug concentration. Characterization of the resistant sublines demonstrates the adaptation that occurs with advancing drug concentrations during in vitro selections. Reduced topoisomerase II mRNA and protein levels were observed in the initial isolate. This reduction was accompanied by a decrease in topoisomerase II activity and cellular growth rate and was associated with 47-fold resistance to topoisomerase II poisons. With advancing resistance, MRP expression increased, with increased VP-16 efflux and reduced accumulation. This adaptation allowed for partial restoration of topoisomerase II activity secondary to increased expression and hyperphosphorylation, with a resultant increase in growth rate. In this cell line, hyperphosphorylation coincided with increased casein kinase II mRNA protein levels, without increased PKC protein levels, suggesting a role for this kinase in the acquired hyperphosphorylation. In this cell line, hyperphosphorylation mediated the increased activity despite a fall in topoisomerase IIα protein levels secondary to an acquired 615 bp deletion in one topoisomerase IIα allele, which resulted in reduced protein levels. In this subline, high levels of resistance were attained as a result of synergism between the reduced topoisomerase IIα levels and MRP overexpression. These studies demonstrate how cellular adaptation to increasing drug pressure occurs and how more than one mechanism can contribute to the resistant phenotype when increasing selecting pressure is applied. Reduced expression of topoisomerase II is sufficient to confer substantial resistance early in the selection process, with synergy from additional mechanisms helping to confer high levels of resistance.
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  • 184
    ISSN: 1573-7365
    Schlagwort(e): Cerebral ischemia ; focal ischemia ; mutant mice ; bcl-2 ; apoptosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Neuronal death after brain ischemia is mainly due to necrosis but there is also evidence for involvement of apoptosis. To test the importance of apoptosis, we investigated the effect of targeted disruption of the apoptosis-suppressive gene bcl-2 on the severity of ischemic brain injury. Transient focal ischemia for 1 hour was induced by occlusion of the middle cerebral artery in homozygous (n=7) and heterozygous (n = 6) bcl-2 knockout mice as well as in their wildtype littermates (n=5). Bcl-2 ablation did not influence cerebral blood flow but it significantly increased infarct size and neurological deficit score at 1 day after reperfusion in a gene-dose dependent manner. The exacerbation of tissue damage in the absence of Bcl-2 underscores the importance of apoptotic pathways for the manifestation of ischemic injury after transient vascular occlusion.
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  • 185
    ISSN: 1573-7373
    Schlagwort(e): non-Hodgkin's lymphoma ; diabetes insipidus ; hypophyseal localization ; chemotherapy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We report the case of a 64 year old male patient with a history of ischemic heart disease who underwent surgery for an abdominal mass. The histological diagnosis was highly malignant non-Hodgkin's lymphoma. After surgery the patient was admitted to our Department and received 6 courses of chemotherapy according to the COP schedule, followed by radiotherapy to the left upper abdominal region and ipsilateral lung base. The patient achieved partial remission. One month later he began to complain of left axillary lymphadenomegaly, polydipsia and polyuria. A NMR brain scan showed a hypophyseal mass. The patient was treated with DDAVP and chemotherapy with the PRO-MACE protocol; the polyuria and lymphadenomegaly disappeared and the size of the hypophyseal mass reduced markedly. The clinical picture was, therefore, attributed to a hypophyseal localization of the non-Hodgkin's lymphoma, which is a very rare manifestation of lymphomatous spread to the central nervous system. Our case is also interesting because it shows that a favorable outcome can be obtained with chemotherapy, provided that the latter is sufficiently aggressive. This is not necessarily the case with radiotherapy which may also be followed by late and severe neurologic sequelae.
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  • 186
    ISSN: 1573-7373
    Schlagwort(e): brain neoplasm ; lymphoma ; CNS ; radiotherapy ; chemotherapy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We treated 23 patients with primary central nervous system lymphoma with a protocol of conventional radiation up to 55±5 Gy followed by 4 to 6 cycles of intravenous doxorubicin (30 mg/m2), vincristine (1 mg/m2) and cyclophosphamide (350 mg/m2), and oral prednisolone (8–30 mg/m2) (VEPA chemotherapy) repeated at 2-week intervals. The median age of the 23 patients was 59 years, and the median World Health Organization performance status score was 2. Seventeen patients received 4 or more courses of the chemotherapy, but 6 received only 1 or 2 courses for various reasons. The median survival time for all 23 patients was 25.5 months and their 5-year survival rate was 23%. These values were 34 months and 32%, respectively, for the 17 patients who received 4–6 courses of chemotherapy. After treatment, decline in performance status unaccompanied with tumor recurrence was observed in 44% of the patients; the incidence was apparently higher in older than in younger patients. The survival results obtained with this combined radiochemotherapy regimen appear to be better than those reported in most previous studies of patients treated with radiation alone. Post-irradiation VEPA chemotherapy appears to be worthy of further evaluation.
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  • 187
    Digitale Medien
    Digitale Medien
    Springer
    Journal of neuro-oncology 44 (1999), S. 255-266 
    ISSN: 1573-7373
    Schlagwort(e): glioma ; immunohistochemistry ; MIB-1 ; apoptosis ; TUNEL
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract With the introduction of new (immuno-)histochemical techniques it is now possible to assess rates of proliferation and apoptosis in brain gliomas using archival paraffin embedded material. As proliferation and apoptosis are related to tumour growth rate quantification of these processes has prognostic value and is related to tumour grading. In this study we assessed the proliferation rate by measuring the Ki-67 labelling index using the MIB-1 antibody (MIB-LI) and the apoptotic rate using the in situ labelling of DNA strand breaks with TUNEL (TUNEL-LI) in 315 supratentorial gliomas. MIB-LI and TUNEL-LI in astrocytomas (A) where significantly lower compared to anaplastic astrocytomas (AA), glioblastomas (GBM) and oligodendroglial tumours [oligodendrogliomas (O) and anaplastic oligodendrogliomas (AO)]. MIB-LI and TUNEL-LI were significantly lower in AA compared to GBM. In astrocytic tumours MIB-LI and TUNEL-LI appeared to be correlated. As the distinction between A and AA is of clinical value but can be difficult histomorphologically we analysed the prognostic value of MIB-LI and TUNEL-LI in gliomas with particular emphasis on A and AA. MIB-LI below 10% was of prognostic value in A and AA, O and AO but not in GBM on univariate survival analysis. TUNEL-LI was of no prognostic value. With multivariate survival analysis MIB-LI lost prognostic significance in O and AO. Astrocytomas with a gemistocytic component (AG) are similar to A with respect to survival and MIB-LI and TUNEL-LI. MIB-LI is of independent prognostic value in A and AA. Assessment of MIB-LI in A and AA can be used as an aid in distinguishing A and AA.
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  • 188
    Digitale Medien
    Digitale Medien
    Springer
    Journal of neuro-oncology 45 (1999), S. 61-67 
    ISSN: 1573-7373
    Schlagwort(e): ependymoma ; chemotherapy ; CNS ; advanced
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Background. The role of chemotherapy in recurrent ependymoma is poorly defined. This study was performed to help clarify the benefits of chemotherapy in this setting. Patients and methods. We retrospectively reviewed the charts of patients with advanced ependymoma of the CNS who received chemotherapy in our institution between 1974 and 1993, inclusive. Sixteen consecutive patients were treated with regimens containing either nitrosourea, platinum, or other combinations exclusive of nitrosourea or platinum. No patient received nitrosourea and platinum concurrently. Two methods were used to define response. The first was a direct comparison of radiographic images before and after chemotherapy more than one month apart. A second broader definition of response that employed four other criteria in addition to imaging studies (symptoms, signs, performance status, and neurologic functional status) was also used. Results. Results were as follows (response rate by imaging studies followed by response rate by scoring in parenthesis): Platinum-based chemotherapy resulted in a 67% (83%) response rate with 33% (0%) remaining stable. Nitrosourea-based regimens resulted in a 25% (60%) response rate with 50% (10%) remaining stable. When combinations other than platinum or nitrosourea were used, 11% (22%) responded and 56% (44%) remained stable. Relative differences in response rates between chemotherapy regimens persisted when the data were analyzed by grade. Median time to progression was 6, 10, and 3 months, respectively. Conclusion. Platinum-based chemotherapy regimens appear to result in higher response rates with lower rates of progression than nitrosourea-based regimens. Other regimens that do not include cisplatinum or nitrosourea appear to be even less effective.
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  • 189
    ISSN: 1573-7373
    Schlagwort(e): high risk medulloblastoma ; chemotherapy ; carboplatin ; oral etoposide
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We report a case of high risk medulloblastoma with leptomeningeal intracranial and spinal metastasis in a 10-year-old girl treated successfully with conventional prolonged chemotherapy without radiotherapy. This is a particular case of medulloblastoma that at onset did not receive standard therapy for medulloblastoma i.e. neither surgery nor craniospinal irradiation. This 10-year-old Chinese girl affected with localized medulloblastoma was previously treated at a medical department in China only with radiotherapy on the posterior fossa. When the child arrived in Italy with progressed metastatic medulloblastoma, she was treated with carboplatin/etoposide association i.v. followed by oral etoposide and partial surgery of the primitive mass. The schedule of chemotherapy was etoposide 300 mg/sqm followed by carboplatin 1000 mg/sqm in one day every 21–28 days for the first six courses, then etoposide 200 mg/sqm and carboplatin 600 mg/sqm in one day every 28–35 days for further 11 courses and oral etoposide 50 mg/sqm/day for ten consecutive days and one week interval between two cycles for one year. At present the girl is alive and disease-free, and has been off-therapy for 31 months. Interestingly, in this case a long-lasting complete remission was obtained without radiotherapy and without myeloablative chemotherapy. Oral etoposide played an important role in achieving a complete remission.
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  • 190
    ISSN: 1573-7373
    Schlagwort(e): apoptosis ; astrocytoma ; glioma ; growth inhibition ; protein kinase C ; signal transduction ; UCN-01
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Recent studies in our laboratory have shown that UCN-01 (7-hydroxystaurosporine), which is a derivative of the non-selective protein kinase inhibitor staurosporine that exhibits relative selectivity for protein kinase C (PKC), is a potent inhibitor of glioma growth in in vitro and in vivo models. This agent exhibits both cytotoxic and cytostatic effects, depending on the time period of drug exposure. In the present study, we examined whether UCN-01-induced cytotoxicity correlated with the induction of apoptosis, and characterized further the time course of this process as a prelude to application of UCN-01 in clinical trials. We first demonstrated that the cytotoxic effects of UCN-01 were associated with the induction of morphological features of apoptosis. Secondly. we identified electrophoretic features of apoptosis semiquantitatively at a series of time points using field inversion gel electrophoresis. These studies showed a peak in the induction of high-molecular-weight DNA fragmentation after 3–6 days of drug treatment. Thirdly, we measured the percentage of cells undergoing apoptosis at various time points using a terminal transferase-catalyzed in situ end-labeling technique, which confirmed a time- and concentration-dependent increase in apoptotic cell numbers. This correlated with a progressive decrease in the percentage of cells that were viable as assessed by trypan blue exclusion. Cell killing peaked within 2–4 days after beginning UCN-01 treatment, but continued at a lower level in the ensuing days. Taken together, these studies demonstrated that extended periods of exposure to UCN-01 are needed for optimal manifestation of cytotoxic effects against glioma cells, a factor that must be taken into consideration in the design of future clinical trials with this agent for malignant gliomas.
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  • 191
    ISSN: 1573-7373
    Schlagwort(e): germinoma ; spontaneous regression ; multiple intracranial ; germ cell tumor ; immunological mechanism ; apoptosis ; MIB-1 index
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract A case of multiple intracranial germ cell tumor in which a pineal tumor regressed spontaneously after resection of the cerebellar mass is reported. Immunohistochemical staining of the cerebellar mass showed that most of the infiltrating lymphocytes were positive for CD3 and CD8. The anti-Ki-67 monoclonal antibody MIB-1 staining of the resected tumor revealed a high MIB-1 positivity ratio (36.1%) among the large tumor cells, and TUNEL staining demonstrated that positivity in up to 6% of the tumor cells. Possible mechanisms responsible for this spontaneous regression including immunological responses and apoptosis induced by T lymphocytes are discussed.
    Materialart: Digitale Medien
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  • 192
    ISSN: 1573-7373
    Schlagwort(e): malignant glioma ; gossypol ; lactate dehydrogenase isoenzymes ; chemotherapy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Gossypol, a polyphenolic compound which depletes cellular energy by inhibition of several intracellular dehydrogenases, has been shown to have antiproliferative activity against human glial tumor cell lines in vitro and in nude mouse xenografts. Human trials of gossypol as a male contraceptive have demonstrated safety of long-term administration. We studied the activity of Gossypol 10 mg PO bid in 27 patients with pathologically confirmed glial tumors which had recurred after radiation therapy. Fifteen patients had glioblastoma, 11 patients anaplastic astrocytoma, 1 patient relapsed low grade glioma. Response was assessed every 8 weeks using CT/MRI scan and clinical criteria including decadron requirement. Treatment was continued until disease progression. Two patients had partial response (PR); 4 had stable disease for 8 weeks or more. One patient maintained a PR with improved KPS for 78 weeks. The other had a PR lasting 8 weeks. Toxicity was mild: 2 heavily pretreated patients had mild thrombocytopenia, 5 patients developed hypokalemia, 3 patients developed grade 2 hepatic toxicity and peripheral edema. Gossypol levels measured by HPLC did not correlate with response or toxicity in this study. We conclude that gossypol is well tolerated and has a low, but measurable, response rate in a heavily pretreated, poor-prognosis group of patients with recurrent glioma. The presumed novel mechanism of action, lack of significant myelosuppression, and activity in patients with advance glioma support further study of gossypol as an antineoplastic agent.
    Materialart: Digitale Medien
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  • 193
    ISSN: 1573-7373
    Schlagwort(e): apoptosis ; cell cycle ; cell death ; medulloblastoma ; T cells ; tumour necrosis factor
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We studied the effect of the treatment of a medulloblastoma cell line by human T cells derived soluble factors. Medulloblastoma is one of the more common aggressive solid neoplasms in children for which there is no adequate therapy. Cell lines established from such tumours may be helpful to test the effect of various molecules on cell proliferation. Previous studies have suggested that T cell-derived factors may be toxic for the medulloblastoma cell line Dev. Cytokines were thought to mediate this effect. In this paper, we described changes in morphology, survival and cell cycle induced in Dev cells cocultured with human T cell lines chronically infected with a retrovirus (HTLV-I) and known to secrete high level of cytokines TNFα, IL1α and IL6. Such cocultures resulted in the death of a part of Dev cells and in decreased proliferation of surviving cells, associated with morphological changes and increase in vimentin expression. Treatment with conditioned medium from infected Dev cells, containing virus induced cytokines, triggered the same effect. Reduction of these effects by TNFα deprivation of conditioned medium suggested that this cytokine may be implicated. Direct treatment of Dev cells with recombinant cytokines indicated that TNFα, but not IL1 or IL6, is associated with Dev cell alterations. TNFα was shown to induce the death of Dev cells by an apoptotic pathway. Furthermore, TNFα had a bimodal effect on the cell cycle of surviving Dev cells. These differential effects of such cytokines on medulloblastoma cells could be therefore of interest for immunotherapy of these tumours.
    Materialart: Digitale Medien
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  • 194
    ISSN: 1573-7373
    Schlagwort(e): malignant melanoma ; brain metastases ; chemotherapy ; fotemustine ; DTIC ; radiation therapy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We report results of a conservative treatment for brain metastases from malignant melanoma with a combination of irradiation and chemotherapy (fotemustine and/or DTIC). To date, 12 patients have been treated. There was a complete remission of the brain metastases in four patients. In two patients a partial remission was observed. The mean survival of the responder was 8.2 months (95% confidence interval 3.8–12.6 months). The most common side effects were thrombocytopenia, leukopenia, and alopecia. Altogether, the treatment was well tolerated. As the outcome of patients with brain metastases from malignant melanoma is generally poor, this combined chemo- and radiation therapy may provide improved care for such patients.
    Materialart: Digitale Medien
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  • 195
    ISSN: 1573-7373
    Schlagwort(e): adenoviral gene transfer ; p53 ; apoptosis ; experimental malignant gliomas
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Adenoviral-mediated gene transfer for the treatment of experimental intrinsic malignant brain neoplasms holds promise. The role, however, of intracellular, adenoviral-mediated p53 expression to inhibit growth of experimental human intracranial malignant gliomas remains largely unexplored. Using the AdCMV.p53 vector we measured the in vitro expression of p53 and the resultant effect upon U251 human malignant glioma cellular proliferation. We further measured the survival of nude mice after intracranial injection of the infected vs. control U251 cells. The growth of the infected U251 cells was inhibited when compared to both the uninfected cells and cells infected with the control vector (AdCMV.Null). Agarose gel electrophoresis confirmed the AdCMV.p53-dependent cellular apoptosis. Nude mice having intracranial injections of the U251 cells infected with the control (AdCMV.Null) vector showed diminished survival. In contrast, mice having intracranial injections of the cells infected with the AdCMV.p53 vector showed 100% survivorship measured 100 days after treatment. Gene therapy via the AdCMV.p53 viral vector holds promise for the clinical treatment of human malignant gliomas.
    Materialart: Digitale Medien
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  • 196
    ISSN: 1573-7373
    Schlagwort(e): radiotherapy ; chemotherapy ; paclitaxel ; brain tumors
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The present study was conducted to evaluate the activity and toxicity profile of radiation (RT) and concomitant chemotherapy in patients with glioblastoma multiforme (GBM). Thirty-nine patients were treated postoperatively with RT and concomitant administration of paclitaxel. Cranial irradiation was initiated 2–3 weeks postoperatively and was administered in 2.0 fractions, one fraction per day, for 5 consecutive days per week, to a total of 60 Gy. Paclitaxel was delivered at a dose of 100 mg/m2 over 3-h once weekly for 6 weeks. Thirty-three patients received all 6 cycles of paclitaxel according to the protocol. Totally, 217 cycles were delivered all of them at full dose. The median relative dose intensity of paclitaxel was 1 (range 0.88–1.1). Three (7.5%) patients achieved complete and 9 (23%) partial response, while 12 (30.5%) patients demonstrated stabilization of the disease. Side effects from combined chemoradiotherapy were mainly mild. Grade III toxicity included infection (7.5%) and alopecia (5%). Median time to progression was 6 (range 0.9–27) months and median survival 10.7 (range 0.9–39.5+) months. The present study has clearly shown that 100 mg/m2 of paclitaxel in 1-h infusion weekly can be safely given concomitantly with RT in patients with GBM with manageable toxicity. However, the efficacy of this combined modality treatment does not appear to be superior to that of RT alone.
    Materialart: Digitale Medien
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  • 197
    Digitale Medien
    Digitale Medien
    Springer
    Journal of neuro-oncology 41 (1999), S. 159-166 
    ISSN: 1573-7373
    Schlagwort(e): neuroblastoma ; chemotherapy ; apoptosis ; dopamine receptors
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract While neuroscientists are often involved in the assessment and care of patients with central nervous system tumors, they are only rarely involved in the case of peripheral nervous system neoplasia. Neuroblastoma is a childhood tumor of the primitive sympathetic nervous system. It is at once one of the most common and one of the most deadly tumors of childhood. The prognosis for children with this tumor has not changed in the past two decades. Clearly, a fresh approach to neuroblastoma is needed. The neuroscientist has much to add to our understanding and treatment of neuroblastoma and its sequelae. Conversely, neuroblastoma has much to teach us regarding the normal development of the neural crest and the aberrant loss of neurons in this lineage. A neuroscientist's approach to neuroblastoma, its biology and clinical features, is presented herein.
    Materialart: Digitale Medien
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  • 198
    ISSN: 1573-7373
    Schlagwort(e): chondrosarcoma ; cranial base ; chemotherapy ; ifosfamide ; doxorubicin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The case of a 46-year old woman with recurrent chondrosarcoma of the cranial base, refractory to neurosurgical intervention and external radiotherapy is reported. She received five cycles of systemic chemotherapy utilizing ifosfamide and doxorubicin which resulted in a durable clinical and radiographic response lasting 52+ months. A review of the management options for recurrent chondrosarcoma of the cranial base is also presented.
    Materialart: Digitale Medien
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  • 199
    ISSN: 1573-7373
    Schlagwort(e): apoptosis ; chemotherapy ; human cell lines ; lovastatin ; medulloblastoma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Medulloblastoma is a malignant paediatric central nervous system tumor with a poor prognosis, stimulating the evaluation of improved treatment strategies. Lovastatin, a competitive inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase, is currently used to treat patients with hypercholesterolemia. This compound also inhibits the production of non-steroidal mevalonate derivatives that are implicated in the control of cellular proliferation, and can induce cell-cycle arrest in vitro. We recently showed that lovastatin inhibited growth and promoted apoptosis of neuroblastoma, the peripheral nervous system ‘cousin’ of medulloblastoma. Therefore the potential of lovastatin as a possible anticancer drug against medulloblastoma was evaluated in vitro. Four medulloblastoma cell lines, Daoy, UW228, D341 Med and D283 Med, were treated with 1–40 µM of lovastatin in vitro. Analysis of cell morphologic changes, cell viability, DNA fragmentation and flow cytometry in all four cell lines showed growth inhibition and induction of apoptosis with lovastatin treatment. As little as 10 µM of lovastatin was sufficient to cause a marked reduction in cell numbers, and more than 20 µM of lovastatin induced 〉90% cells to undergo apoptosis, after intervals ranging between 36 and 96 h, depending on the cell line. Lovastatin induced apoptosis in these cell lines was concomitant with cell cycle arrest in G1. The attached cell lines UW228 and Daoy were more sensitive to lovastatin than D283 Med and D341 Med. Daoy cells which survived several cycles of lovastatin treatment could still be induced to undergo apoptosis after longer treatment times. The efficient induction of apoptosis by lovastatin favours this drug as a potential new avenue of therapeutic intervention for medulloablastoma.
    Materialart: Digitale Medien
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  • 200
    Digitale Medien
    Digitale Medien
    Springer
    Journal of neuro-oncology 43 (1999), S. 249-257 
    ISSN: 1573-7373
    Schlagwort(e): primary CNS lymphoma ; radiotherapy ; chemotherapy ; neurotoxicity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Primary central nervous system lymphoma (PCNSL) is a relatively uncommon primary brain tumor, but it has become the focus of many clinical trials because of its rising incidence and unique sensitivity to systemic chemotherapeutic agents. Radiotherapy can achieve high response rates and remissions in most patients, but survival is usually only 12–18 months because disease recurs. The addition of systemic chemotherapy, particularly intravenous methotrexate, had markedly improved disease control and many patients can achieve a durable remission and occasionally cure of their disease. Conventional systemic lymphoma drug combinations such as cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) are ineffective. High-dose methotrexate is the single most active and important agent in the treatment of this disease. Whether improved disease control can be accomplished by adding other drugs to high-dose methotrexate or whether it is sufficient as a single agent has yet to be answered. High-dose methotrexate combined with cranial irradiation yields a median survival of at least 40 months and five year survival rates of 22%. However, neurotoxicity is substantial in a significant proportion of patients, particularly those over the age of 60 at the time of treatment. As many as 50% of such patients develop severe dementia. This is particularly important in a disease where approximately half of patients above the age of 60 had presentation. Efforts are now being directed towards not only improving disease control but also minimizing late neurotoxicity. Most efforts are currently directed towards using chemotherapy as the sole modality in the treatment of PCNSL, but both an optimal chemotherapy regimen, and the role of radiotherapy remain to be determined.
    Materialart: Digitale Medien
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