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Biomedical subjects

G Roos

Publications and source records attributed to G Roos.

At least 109 records · Page 6Linked to original sources
PubMed1994

Cell cycle effects of the anti-rheumatic agent CPH82.

The benzylidated podophyllotoxin glycoside CPH82, a potentially useful drug for treatment of RA, was tested in vitro on nine human haematopoietic cell lines for cell kinetic effects. Previous studies have shown CPH82 to behave like a colchine-type 'metaphase' blocker. The distribution of cells within different cell cycle compartments (G1, S, G2 and M) was analysed by a novel method using dual parameter flow cytometric analysis of stage specific antigens (proliferating cell nuclear antigen and Ki-67). With CPH82 concentrations chosen to mimic clinical conditions, eight out of nine lines showed an accumulation of cells in the G2 phase of the cell cycle. In many lines a delayed progress through S seemed to occur. Three lines were blocked in both G1 and G2, whereas the major effect on one line (HL-60) was an accumulation of cells in the G1 phase. Progression of M cells seemed only slightly delayed for some cell lines. In comparison with two related 'metaphase' blocking agents (podophyllotoxin and taxol), CPH82 had a different and dose-dependent pattern of cell cycle retardation. It is speculated that the cell kinetic action of CPH82 might give insight into the question why it, unlike other 'metaphase' blockers, has proved valuable in the treatment of RA.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1994

Application of dual parameter analysis in flow cytometric DNA measurements of paraffin-embedded samples.

In a comparison of flow cytometric DNA measurements on fresh and paraffin-embedded material from primary squamous cell carcinomas of the head and neck region, we discovered that previously undetected aneuploid clones could be detected by dual parameter analysis of cytokeratin and DNA applied to disintegrated cells from paraffin sections. Using this new approach the correlation coefficient between DNA-indices from fresh and paraffin-embedded material increased from 0.423 to 0.904.

Aneuploidy↗
PubMed1994

Simultaneous immunoglobulin/T-cell receptor gene rearrangements and multiclonality in childhood acute lymphoblastic leukemia.

Twenty-five children less than 16 years of age with acute lymphoblastic leukemia (ALL) were investigated with immunologic, cytogenetic and molecular genetic techniques at diagnosis. All pre-B-cell ALL showed clonal rearrangements in the immunoglobulin heavy chain gene (JH and/or C mu). A very high proportion of the pre-B-cell leukemias (17 of 23 cases) also showed clonal rearrangements in T-cell receptor genes (T gamma and/or T beta). The two T-cell leukemias exhibited clonal T-cell receptor gene rearrangements and in one JH and kappa light chain rearrangements also. The T-cell receptor gene rearrangements found in pre-B-cell leukemias appeared to occur randomly with respect to the T beta and T gamma genes. A significant proportion of the leukemias (at least 24%) seemed to harbor more than one malignant (sub)clone at diagnosis. Cytogenetic studies revealed a clonal abnormality in 10 cases. Only 2 showed hyperdiploidy (> 50 chromosomes). The only correlation between cytogenetic findings and rearrangement patterns was extra bands corresponding to a possible trisomy of chromosome 14. Our data indicate, in line with previous studies, that childhood ALL has complex rearrangement patterns not useful for lineage sub-classification. For this purpose immunophenotyping appears to be superior. However, molecular analysis can reveal the presence of more than one clone not detected by immunophenotyping or karyotyping, and distribution of clones in different compartments. In this study no correlation with clinical outcome was observed.

Adolescent↗
PubMed1994

Proliferation of human renal cell carcinoma studied with in vivo iododeoxyuridine labelling and immunohistochemistry.

Tumor cell proliferation is one interesting cell biological parameter of possible predictive value for prognosis. In the present study 176 tumor and 33 kidney cortex samples from 33 patients with renal cell carcinoma were studied after immunohistochemical detection of in vivo labelled iododeoxyuridine. The tumors had a mean labelling index (LI) of 1.06 +/- 0.59%, significantly different from LI of kidney cortex tissue 0.08 +/- 0.09% (p < 0.001). There was a tendency towards increasing LIs at higher clinical stages. No correlation was found between LI and tumor size. A significant difference existed for LIs between diploid and aneuploid tumors (p = 0.037). Within the limited number of patients with a relatively short follow-up, Kaplan-Meier curves indicated that LI might provide prognostic information.

Adult↗
PubMed1994

Cell kinetics of head and neck squamous cell carcinomas. Prognostic implications.

Forty-three squamous cell carcinomas of the head and neck region were in vivo labelled with the thymidine analogue iododeoxyuridine. Combined flow cytometric (FCM) and immunohistochemical (IHC) analysis was performed, and the following parameters calculated: labelling index (LI), S-phase time (TS) and potential tumor doubling time (Tpot). Complete FCM and IHC analyses could successfully be performed in 31 cases, showing a median LI of 13.6% with FCM and 9.1% with IHC. A correlation achieved between LI/FCM and LI/IHC was due to the aneuploid cases, whereas the diploid cases showed no such correlation. Data indicated that Tpot calculated with LI from IHC (Tpot/IHC) might be a prognostic factor, in contrast to Tpot determined using LI/FCM.

Adult↗
PubMed1994

Telomerase activity in vivo in human malignant hematopoietic cells.

In somatic cells, each DNA replication round gives a shortening of the telomere ends as a consequence of incomplete lagging strand synthesis. Telomeres are essential for chromosomal integrity and extensive telomere length reduction is associated with increased instability of the genome. In germ line cells and in established cell lines, telomerase activity maintains the length of the telomeres by de novo synthesis of telomeric repeats, in humans (T2AG3)n. Recently, it was for the first time shown the existence of telomerase activity in human ovarian carcinomas. In the present study we show that telomerase activation can also occur in human hematopoietic tumor cells in vivo. Cell extracts from 19 cases with leukemia, lymphoma and myeloma were tested for telomerase activity using an in vitro assay with (T2AG3)3 or permutations of this sequence as primers. Eight cases demonstrated an RNAse A sensitive ability to add new nucleotides to the human telomere sequence. Nine acute leukemias were tested telomerase negative. Our data demonstrate that telomerase activation in vivo seems to be a common event in B cell neoplasias with a mature immunophenotype like non-Hodgkin's lymphoma and myeloma, in contrast to acute leukemias of B, T or myeloid cell origin. Telomere length evaluation indicated no marked differences between samples with or without telomerase activity which could argue for a telomere length independent mechanism for telomerase activation in at least some cases.

Base Sequence↗
PubMed1994

Inter-institutional reproducibility of flow cytometric DNA-analysis in breast carcinomas.

In order to study interinstitutional reproducibility of flow cytometric DNA-analysis (DNA-FCM), frozen pieces from 30 consecutive breast carcinomas were analysed by 5 laboratories. Different instruments, preparation and DNA staining methods were used. A concordance in DNA-ploidy status was obtained in 26 of the 30 tumours. The discrepancy can mainly be explained by intratumoural DNA-heterogeneity since a complete agreement in ploidy status was obtained when four of the laboratories analysed the same cell suspension, where solid bits showed differing results. The sampling method seems therefore to be a crucial step for the results and needs further studies. As far as the estimation of S-phase fraction was concerned, one laboratory obtained significantly higher values compared to the other four. The correlation between the other four laboratories varied between r = 0.66-0.92.

Academies and Institutes↗
PubMed1993

Tumor-cell proliferation and prognosis in renal-cell carcinoma.

In the present study the prognostic value of tumor S-phase fraction was evaluated in 69 patients with renal-cell carcinoma. The proportion of S-phase cells was calculated from DNA histograms by flow cytometry in multiple samples from each tumor. The mean tumor S-phase percentage varied between 1.0 and 17.0%, mean 7.5%, with a significant difference between diploid and non-diploid tumors. Stage-I tumors showed significantly lower S-phase values than tumors of stages II/III and IV. Histopathological grade correlated with fraction of cells in S-phase. Nineteen tumors were homogeneously diploid, I was tetraploid and 49 were aneuploid. Heterogeneity concerning S-phase values was found in 46 of the 69 tumors and concerning DNA ploidy in 34 tumors. Survival time was longer for patients with diploid tumors than for those with aneuploid tumors. Patients with S-phase values < 7.5% had a longer survival time than patients having tumors with S-phase values > 7.5%. Within the group of aneuploid tumors, patients with S-phase values < 7.5% had a significantly better prognosis. In multivariate analysis, only tumor stage and S-phase gave significant independent prognostic information. The S-phase fraction seems to be an additional prognostic parameter for patients with renal-cell carcinoma.

Adult↗
PubMed1993

DNA fingerprinting of renal cell carcinoma with special reference to tumor heterogeneity.

Genomic alterations in renal cell carcinoma were investigated by DNA fingerprinting using the simple repetitive oligonucleotide probe (CAC)s. Nine of ten tumors showed somatic changes in the fingerprint pattern compared with constitutional DNA. The most consistent changes were deletions and/or decrease in intensity of a band. When using two or three samples from different parts within the tumor, up to three different cell clones could be detected. These results indicate that DNA fingerprinting analysis can be a useful technique for the study of genomic alterations and tumor heterogeneity in renal cell carcinoma.

Carcinoma, Renal Cell↗
PubMed1993

Relation between the incorporation of 5-fluorouracil into liver carcinoma and normal tissue RNA at hepatic arterial administration in the rat is altered by overnight starvation.

The cytotoxicity of 5-FUra has been related to its incorporation into RNA. In a model of secondary liver cancer in the rat, the incorporation of 5-FUra into the acid-soluble fraction, RNA and DNA of several normal tissues and an adenocarcinoma of the colon transplanted to the liver was determined. A therapeutic labelled dose of the drug was infused via the hepatic artery for 2 hr and the rats killed 1 hr later. Half of the rats were starved overnight before treatment. The incorporation of 5-FUra into liver and intestinal RNA increased at starvation. It was unchanged in kidney and bone marrow. The incorporation into tumor RNA decreased insignificantly. The incorporation into tumor RNA was significantly higher than in hepatic, intestinal, and renal RNA at ad libitum feeding. This difference disappeared at overnight starvation.

Adenocarcinoma↗
PubMed1993

Interleukin-2-administration intravenously and intrapleurally in a patient with primary pulmonary adenocarcinoma. Cellular responses in peripheral blood, intrapleural fluid and bronchoalveolar lavage.

A case report of a patient who suffered from a rapidly progressive lung adenocarcinoma with malignant pleural effusions, is given. The patient failed to respond on two series of conventional cytotoxic drug therapy (Carboplatin, Etoposide). Interleukin-2 (IL-2) treatment was first started as intrapleural instillations (3.0 million IU per day in 6 days). A clear clinical response was achieved with ceasing of the pleural effusion, and the overall disease became stable. In the peripheral blood, there was an increase of CD4 positive lymphocytes that remained elevated after finishing the installation period. Both in bronchoalveolar lavage (BAL), and in the pleural fluid, there was a marked decrease of cells recovered, possibly due to an enhanced tissue attachment of activated cells. A second analysis with subtyping of lymphocytes in BAL was impossible due to the low cell number. In the pleural fluid, the fractions of CD3 positive cells increased from 20 to 71% while the ratio between CD4 and CD8 remained persistently elevated at 6.1:1. Because of the disappearance of the pleural effusion, the patient was thereafter treated with IL-2 given as a continuous infusion (18 million IU per square-metre during 24 hours for 5 days). Hereby a more pronounced cell response was achieved in the peripheral blood. In contrast to the intrapleural treatment route, not only CD4 positive cells, but also the numbers of natural killer cells (NK) increased. However this treatment was also associated with a much higher degree of side effects. It can be concluded from both intrapleural and intravenous IL-2 therapy, that a clinical and immunological response was achieved.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1993

Proliferating cell nuclear antigen and Ki-67 antigen expression in human haematopoietic cells during growth stimulation and differentiation.

By flow cytometric dual parameter analysis of proliferating cell nuclear antigen (PCNA) and the Ki-67 antigen a detailed cell cycle analysis can be performed. In this study the coordinated expression of these two growth-related antigens was investigated in human haematopoietic cells at entrance into the cell cycle as well as at exit from the cycle. In mitogen-stimulated peripheral blood lymphocytes entering the first cell cycle, the Ki-67 antigen was found to be expressed in S phase cells and not in G1 cells. Thus, the Ki-67 antigen expression in PCNA-positive S phase cells differed between continuously cycling cells and cells entering the cell cycle. Based on this difference, it was possible to visualize and evaluate the recruitment of cells into the first cell cycle from a resting stage. This new cell cycle parameter can give additional information concerning tumour growth. The Ki-67 antigen was also studied during different stages of G1 and was found to be expressed at high levels in early G1 cells compared with other parts of G1.

Cell Cycle↗
PubMed1993

Prognostic significance of serum lactic dehydrogenase levels and fraction of S-phase cells in non-Hodgkin lymphomas.

Sixty-four untreated patients with non-Hodgkin lymphomas (NHL) were analyzed with respect to fraction of S-phase cells in tumor material and serum lactic dehydrogenase (LD) levels. A significant correlation between the two variables was found in the low-grade (LGM) (r = 0.44, p < 0.01), but not in the high-grade (HGM) lymphomas. Shorter survival times were found for patients with tumors showing a high fraction of S-phase cells (> 4%) (p < 0.001) as well as for patients with elevated LD values (> or = 7.5 mukat/l) (p < 0.001). A multivariate analysis showed clinical stage (p < 0.001), S-phase fraction (p = 0.002) and age (p = 0.002) to be independent prognostic factors. For serum LD a borderline value (p = 0.05) was found, whereas morphology and B-symptoms were non-significant. LD level, but not fraction of S-phase cells, added prognostic information for LGM lymphomas (p < 0.001). For HGM lymphomas, the clinical stage was the strongest factor for prediction of prognosis. We conclude that the fraction of S-phase cells describes the biological behavior in a more reliable way than morphology (HGM vs LGM) and better identifies lymphomas with poor or good prognosis. The strong additional prognostic information obtained by serum LD within LGM lymphomas is assumed to be due to an association with the tumor burden.

Adult↗
PubMed1993

Local host response in the lower respiratory tract in nephropathia epidemica.

Various lines of evidence suggest a respiratory route of transmission of nephropathia epidemica (NE). To study the response of the respiratory tract in NE, fiberoptic bronchoscopy with bronchoalveolar lavage (BAL) was performed in 5 patients in the acute phase of the disease. Compared to a reference group of 15 healthy individuals, BAL fluid of NE patients contained significantly higher total numbers of cells (p < 0.05) and significantly higher numbers of lysozyme-positive macrophages (p < 0.01), CD8+ T cells (p < 0.01), and natural killer (NK) cells (p < 0.01). There was no significant difference in numbers of CD4+ T cells, B cells, or neutrophils. When blood samples of 16 patients were examined at various intervals after onset of NE, a significant decrease in the number of NK cells (p < 0.01) was found in the acute phase of the disease. The findings are compatible with the presence of a local host response in the lower respiratory tract to NE virus infection.

Acute-Phase Reaction↗
PubMed1993

Non-Hodgkin's lymphoma in northern Sweden. A retrospective analysis of morphologic diagnosis and stage in a material from the Swedish Cancer Registry.

Morphologic diagnosis and clinical stage were studied in a retrospective material of non-Hodgkin's lymphomas comprising 352 patients diagnosed 1978 until 1982 and reported to a regional cancer registry. Classification was made according to the original Kiel classification. Patients who could be classified as belonging to low- (46%) or high-grade (47%) malignancy groups (n = 337) were further studied. The median age was high, 65 years, which probably reflects the low degree of selection in a regional register material compared to most hospital register-based materials. The proportion of stage I cases was rather high, in low-grade lymphomas 24%, and in high-grade 39%, which can be attributed to incomplete staging procedures in old patients. The aim of the study was to illustrate the distribution according to morphologic subclasses and clinical features in a material with a low degree of patient selection.

Adolescent↗
PubMed1993

Ig-gene and T-cell receptor gene rearrangements in a secondary, mono-histiocytic malignancy.

In 1984, a 21-year-old male was diagnosed with an acute lymphoblastic leukemia of pre-B cell type. Treatment with chemotherapy, including alkylating agents and prophylactic radiotherapy to the central nervous system, induced a complete remission. In June 1990, a biopsy from a supraclavicular node revealed a malignancy of mono-histiocytic type with erythrophagocytosis. Soon thereafter bone marrow involvement was found. No remission was achieved and the patient died in December 1990. DNA from bone marrow and lymph node obtained 1990 showed clonal rearrangements of both the immunoglobulin heavy-chain gene and the T-cell receptor gamma chain gene. This unusual case illustrates a typical secondary malignancy proven to be separate from the primary neoplasm judged by morphological appearance, immunophenotype and cytogenetic constitution. Coexistent clonal rearrangements of immunoglobulin and T-cell receptor genes have been reported in acute non-lymphoblastic leukemias and notably in cases expressing TdT, interpreted as a predominant lymphoid commitment of the tumor cells. In the present case, however, the malignant cells had a differentiated phenotype and showed erythrophagocytosis, indicating a more mature mono-histiocytic cell type. However, also CD3 expression was found by immunohistochemistry of frozen sections which might indicate a biphenotypic malignancy.

Adult↗
PubMed1993

Analysis of the epitopes of proliferating cell nuclear antigen recognized by monoclonal antibodies.

BACKGROUND: Monoclonal antibodies to proliferating cell nuclear antigen (PCNA) are increasingly used for evaluation of cell proliferation especially in diagnostic pathology. To understand the different staining characteristics of such antibodies, we found it important to map the reactive epitopes in detail. EXPERIMENTAL DESIGN: Overlapping, synthetic 15-mer peptides encoding the entire PCNA amino acid sequence were analyzed for reactivity with 6 anti-PCNA monoclonal antibodies using enzyme-linked immunosorbent assay and flow cytometric competition analysis. One immunodominant region was studied using a set of peptides with single amino acid substitutions. Further epitope localization was obtained by immunoblotting of fusion protein constructs. RESULTS: The epitopes recognized by the antibodies could be assigned to specific peptides. Five monoclonal antibodies (19A2, 19F4, TO17, TO30, PC10) reacted with the same protein region (aa 111-125) whereas one antibody (TOB7) recognized a separate region of the protein (aa 181-195). The reactivity pattern with 8 recombinant PCNA-fusion proteins agreed with the peptide data. The immunodominant aa 111-125 peptide reactive antibodies differed concerning immunofluorescence patterns. These differences could be attributed to epitope microheterogeneity within this peptide as determined by reactivity with Ala-substituted peptides. The 19A2, 19F4 and PC10 antibodies showed nuclear fluorescence and similar but not identical peptide recognition patterns. Compared with 19A2 and 19F4, the PC10 antibody was directed against a simpler epitope. TO17 and TO30 gave cytoplasmic filamentous staining and their epitopes were different from those defined by the other monoclonal antibodies. CONCLUSIONS: The results indicate that induced anti-PCNA antibodies recognize well defined linear epitopes, in contrast to PCNA autoepitopes which are strongly dependent on the protein conformation.

Amino Acid Sequence↗