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Biomedical subjects

K Grønbaek

Publications and source records attributed to K Grønbaek.

At least 19 recordsLinked to original sources

Randomized controlled azathioprine withdrawal after more than two years treatment in Crohn's disease: increased relapse rate the following year.

INTRODUCTION: Azathioprine is effective for maintenance of remission in Crohn's disease, however, duration of efficacy and the dose response relationship has not been fully evaluated. AIMS: To investigate whether patients kept in remission by azathioprine treatment for >2 years benefit from further treatment, and to explore dose-response relationship. PATIENTS AND METHODS: In an open 12-month trial, patients with inactive Crohn's disease after >2 years (median 37 months) of azathioprine treatment were randomized to azathioprine withdrawal or continued treatment. Primary end point was relapse defined as: (i) Crohn's disease activity index rise >/= 75, and Crohn's disease activity index >150 or (ii) disease activity requiring intervention. RESULTS: Of 29 patients, 28 completed the observation period or relapsed. Eleven of 13 patients (85%) continuing azathioprine remained in remission compared with seven of 15 (47%) observed without azathioprine (P = 0.043). In patients who had been treated with azathioprine >1.60 mg/kg/day the difference was even more pronounced, eight of nine (89%) vs. four of 12 (33%) respectively (P = 0.017). CONCLUSIONS: Patients with Crohn's disease in remission after >2 years of continuous azathioprine treatment will benefit from further continued treatment. Further controlled studies with azathioprine doses <2.0 mg/kg/day are needed.

Adult↗

A case of lymphoblastoid natural killer (NK)-cell lymphoma: association with the NK-cell receptor complex CD94/NKG2 and TP53 intragenic deletion.

The clinical, histological, phenotypic and genotypic features of a lymphoblastoid natural killer (NK)-cell lymphoma presenting in the skin in a young caucasian woman are described. The disease behaved aggressively, but long-lasting remission was obtained by combination chemotherapy followed by autologous bone marrow transplantation. The blastoid cells were positive for terminal deoxynucleotidyl transferase, CD34, CD56 and CD4. Furthermore, the NK-cell receptor complex CD94/NKG2 was strongly expressed, as shown by examination with reverse transcription-polymerase chain reaction. The T-cell receptor (TCR)-gamma genes were in germline, and with the exception of CD4 all T-cell antigens were negative, including CD3, TCR-beta, TCR-delta, TIA-1, granzyme B and perforin. Epstein-Barr virus was negative, and no expression was seen of myeloid cell-associated markers. Molecular analysis showed no abnormalities of the CDKN2A (p16), CDKN2B (p15) or TNFRSF6 (Fas) genes. By contrast, a 34-bp deletion in exon 7 of the TP53 (p53) gene was detected. It is suggested that lymphoblastoid NK-cell lymphoma, which is a rare but distinctive disease, originates from NK cell precursors and may be associated with and possibly caused by alterations in the TP53 gene. Experience is too limited to warrant therapeutic suggestions. However, stem cell transplantation may be a useful option in younger patients.

Adult↗

Interobserver variation in interpretation of serial liver biopsies from patients with chronic hepatitis C.

Reliable and accurate assessment of liver histopathology in patients with chronic hepatitis C is important for decision regarding treatment and for evaluation of therapy. However, little data on interobserver variation have been published. In this study, five specialist histopathologists evaluated 46 liver biopsies from 20 patients treated with interferon-alpha. Knodell's and Ishak's scoring systems, De Groote's classification and a four level general necro-inflammatory activity score (GNAS) were applied. Besides kappa statistics, slide by slide analysis was performed. We defined an acceptable slide by slide agreement as eight of ten observer pairs agreed on 80% of the slides. The best agreement was seen for Knodell's and Ishak's fibrosis score, De Groote's classification and GNAS (mean weighted kappa (kappa(w)) = 0.49, 0.51, 0.50 and 0.44, respectively). By condensing data from Knodell's and Ishak's scores to presence or absence of cirrhosis and piecemeal necrosis respectively, concordance was substantial concerning cirrhosis (mean kappa = 0.69 and 0.72, respectively) but only moderate concerning piecemeal necrosis (mean kappa = 0.40 and 0.39, respectively). Slide by slide analysis showed the highest agreement on Knodell's fibrosis score and GNAS; only one point of difference in score was to be accepted to obtain 'eight of ten' agreement. In contrast, five points of difference were necessary to accept in order to reach the same agreement for Knodell's total activity score. Moreover, in serial biopsies the GNAS was sufficient to detect changes in disease activity following treatment. Thus, a simple scoring system with four category scales was reproducible and sufficient for detection of therapy induced changes.

Antiviral Agents↗

Interferon alfa-2b alone or combined with recombinant granulocyte-macrophage colony-stimulating factor as treatment of chronic hepatitis C.

BACKGROUND: To compare the effect of combination therapy with interferon-alpha (INF-alpha) and granulocyte-macrophage colony-stimulating factor (GM-CSF) to monotherapy with INF-alpha in patients with chronic hepatitis C infection. METHODS: Forty-five consecutive patients with chronic hepatitis C, all presenting with elevated serum alanine aminotransferases and viremia, were randomized to receive either 1) INF-alpha + GM-CSF for 3 months followed by INF-alpha alone for 9 months (n = 23) or 2) INF-alpha for 12 months (n = 22). Both drugs were administered 3 times weekly in doses of 3 mU (INF-alpha) and 50-100 microg depending on body weight (GM-CSF). RESULTS: At baseline, there was no difference between the treatment groups in terms of age, sex, ALT level, viral load, genotype or histological activity and fibrosis in a pretreatment liver biopsy. After 12 months' treatment, more patients treated with GM-CSF+ INF-alpha compared to patients receiving monotherapy had normalized ALT, 65% and 32%, respectively (P = 0.03), but there was no difference in percentages of patients with viral clearance between the 2 groups, 48% and 32%, respectively (P = 0.27). At 6 months' follow-up, the biochemical response had declined to 35% in the combination therapy group and to 23% in the monotherapy group (P = 0.37); viral clearance had declined to 22% and 27%, respectively (P = 0.67), and the overall sustained response rate was 22% and 23%, respectively (P = 1.00). CONCLUSIONS: Even though patients receiving INF-alpha + GM-CSF had a significant better biochemical response during treatment compared to patients receiving monotherapy, the sustained biochemical and virological response was not increased. Thus, GM-CSF hardly plays any role in the future treatment of chronic hepatitis C.

Adult↗

Mutational analysis of the tumour suppressor gene MMAC1/PTEN in malignant myeloid disorders.

The candidate tumour suppressor gene MMAC1/PTEN located at chromosome 10q23.3 has been reported to be frequently mutated in a number of solid tumours. Less is known about its status in leukaemia. In the present study we first analysed 13 leukaemia cell lines for mutations and homozygous deletions in MMAC1/PTEN using PCR and denaturing gradient gel electrophoresis (DGGE). We identified an intragenic deletion including MMAC1/PTEN exons 2-5 in an acute myelocytic leukaemia cell line, HL-60 blast, and an insertion of four nucleotides in exon 5 in an acute monocytic leukaemia cell line, U937. Analysis of 59 patients with acute myeloid leukaemia (AML), 26 patients with myelodysplastic syndromes (MDS) and 10 patients with chronic myeloid leukaemia (CML) only revealed a polymorphic base substitution in codon 44 in one AML patient, suggesting that mutations in the MMAC1/PTEN gene are infrequent genetic aberrations in myeloid leukaemia.

Acute Disease↗

Concurrent disruption of p16INK4a and the ARF-p53 pathway predicts poor prognosis in aggressive non-Hodgkin's lymphoma.

The INK4a/ARF locus at chromosome 9p21 encodes two structurally and functionally distinct molecules with tumor-suppressive properties. p16INK4a controls cell cycle progression by inhibiting phosphorylation of the retinoblastoma protein (Rb), while ARF prevents MDM2-mediated degradation of p53. By using a panel of PCR-based methods, we have examined the status of the p16INK4a, ARF and p53 genes in 123 cases of non-Hodgkin's lymphoma (NHL) at diagnosis. Alterations of one or more of these genes were detected in seven of 36 (19%) cases with low- to intermediate-grade histology, and in 35 of 87 (40%) cases with aggressive histology. For the aggressive lymphomas, the Kaplan-Meier estimate of overall survival for cases with disruption of either p16INK4a or the ARF-p53 pathway was not different from cases with retention of both pathways (5 year survival 45% vs 35%; P= 0.85), suggesting that selective inactivation of one of the pathways does not significantly influence overall survival. By contrast, the 5-year survival was only 7% for cases with concurrent disruption of p16INK4a and the ARF-p53 pathway vs 38% for cases with retention of one or both pathways (P = 0.005). Similar results were obtained when the analysis was confined to diffuse large B cell lymphomas (P= 0.019). On stepwise multivariate regression analysis including factors from the international prognostic index, concurrent disruption of p16INK4a and the ARF-p53 pathway was an independent negative prognostic factor in NHL with aggressive histology (P = 0.006). Our results suggest that the compound status of the p16INK4a and ARF-p53 pathways is a major determinant of outcome in NHL.

ADP-Ribosylation Factors↗

Primary cutaneous B-cell lymphoma: a clinical, histological, phenotypic and genotypic study of 21 cases.

The clinical, histological, phenotypic and genotypic features of 21 primary cutaneous B-cell lymphomas (CBCLs) have been investigated. The patients were 13 men and eight women aged 34-91 years (median 67) at diagnosis. Eighteen patients had localized disease, and three had multiple skin lesions at diagnosis. Twelve patients developed cutaneous or extracutaneous recurrences, and five died from malignant lymphoma 7-84 months (median 36) after diagnosis. Histological examination showed features of marginal zone/mucosa-associated lymphoid tissue (MALT)-type lymphoma in 12 cases. Three of these had transformed to diffuse large B-cell lymphoma (DLBCL) in relapse biopsies. The remaining cases were seven primary DLBCLs and two cases tentatively classified as follicle centre cell (FCC) lymphoma. The neoplastic B cells showed similar phenotypes and genotypes in most cases (CD20+, CD79+, CD5-, CD10-, cyclin D1-, bcl-2+, bcl-x-, bax-, t(14;18)-negative). p53 protein was expressed in five cases, and four harboured mis-sense or loss-of-function mutations in the p53 gene. Deletion or promoter region hypermethylation of the p16INK4a gene was detected in two patients with DLBCL. The level of retinoblastoma protein expression and the proliferative fraction were significantly higher in DLBCL (> 50%) than in MALT- or FCC-type lymphomas (< 10%). Features associated with an unfavourable prognosis were the presence of multiple skin lesions at diagnosis, transformation from MALT-type lymphoma to DLBCL, and possibly p16INK4a aberrations. It is concluded that most CBCLs are dissimilar from FCC lymphomas and seem to be more closely related to marginal zone/MALT-type lymphomas. It is also suggested that there are fundamental differences between DLBCL and other histological categories of CBCL, indicating that cutaneous DLBCL is a separate entity with an increased growth potential and genetic features similar to DLBCL originating in other anatomical sites.

Adult↗

In situ T cell responses against melanoma comprise high numbers of locally expanded T cell clonotypes.

It is well established that melanoma cells express Ags that are recognized by autologous T cells in vitro. Tumor-infiltrating lymphocytes in situ comprise clonotypic T cells, suggesting that their expansion is driven by Ag stimulation. Still, little is known about the detailed characteristics of the in situ T cell response. In the present study, we scrutinized this response by analyzing multiple metastatic lesions for the presence of clonotypic T cells. This approach was chosen to distinguish whether the clonal T cell expansion occurs as a systemic or localized phenomenon. TCR clonotype mapping of six s.c. metastases from two patients revealed the presence of multiple (from 40 to >60) clonotypic T cells in all lesions. Clonotypic T cells were present in TCR beta-variable regions expressed both at high and low levels. Comparison of the T cell clonotypes present in different lesions from individual patients demonstrated that, in general, clonotypes were exclusively detected in a single lesion. Hence, anti-melanoma T cell responses are much more heterogeneous than previously anticipated and accommodate a predominance of strictly localized T cell clonotypes.

Antigens, Neoplasm↗

Natural history and etiology of liver disease in patients with previous community-acquired acute non-A, non-B hepatitis. A follow-up study of 178 Danish patients consecutively enrolled in The Copenhagen Hepatitis Acuta Programme in the period 1969-1987.

BACKGROUND/AIMS: Consecutive patients originally diagnosed with acute non-A, non-B hepatitis were followed up to assess the long-term morbidity and mortality and to re-evaluate the etiology in surviving patients. METHODS: Follow-up was performed in 178 patients with acute non-A, non-B hepatitis enrolled in the Copenhagen Hepatitis Acuta Programme in the period 1969-1987. Mortality and morbidity were assessed using: i) death certificates and ii) diagnoses at discharge following all somatic admissions. All patients who were alive were offered a re-examination encompassing clinical, biochemical and virological evaluation. RESULTS: After a median of 23 years, 71 (40%) had died and seven (4%) were untraceable. Overall mortality and mortality due to cirrhosis and accidents, mainly intoxication with drugs, were significantly higher compared to those of an age- and sex-matched Danish population. Chronic hepatitis had been diagnosed in 19 (11%) and cirrhosis in 16 (9%). Of 100 patients who were alive, 57 accepted a re-examination. Anti-HCV was detected in 24 (42%) and 19 (33%) were HCV-RNA positive. Of the viremic patients, 11 (58%) had elevated P-ALT, but only three (16%) had already been diagnosed with HCV infection. A history of intravenous drug use was tantamount to anti-HCV positivity. CONCLUSIONS: Danish patients with community-acquired acute non-A, non-B hepatitis had an increased mortality due to liver cirrhosis during the first years after the acute infection. Alcohol was the etiological agent in several cases, but HCV infection may also have been present. However, the long-term HCV-related morbidity and mortality were low.

Acute Disease↗

Somatic Fas mutations in non-Hodgkin's lymphoma: association with extranodal disease and autoimmunity.

Fas (APO-1/CD95) is a cell-surface receptor involved in cell death signaling. Germline mutations in the Fas gene have been associated with autoimmune lymphoproliferative syndrome, and somatic Fas mutations have been found in multiple myeloma. We have examined the entire coding region and all splice sites of the Fas gene in 150 cases of non-Hodgkin's lymphoma. Overall, mutations were identified in 16 of the tumors (11%). Missense mutations within the death domain of the receptor were associated with retention of the wild-type allele, indicating a dominant-negative mechanism, whereas missense mutations outside the death domain were associated with allelic loss. Fas mutations were identified in 3 (60%) MALT-type lymphomas, 9 (21%) diffuse large B-cell lymphomas, 2 (6%) follicle center cell lymphomas, 1 (50%) anaplastic large cell lymphoma, and 1 unusual case of B-cell chronic lymphocytic leukemia with a marked tropism for skin. Among the 16 patients with somatic Fas mutations, 15 showed extranodal disease at presentation, and 6 relapsed in extranodal areas. Ten of 13 evaluable patients showed features suggestive of autoreactive disease. Our data indicate that somatic disruption of Fas may play a role in the pathogenesis of some lymphomas, and suggest a link between Fas mutation, cancer and autoimmunity.

Adult↗

Concurrent disruption of cell cycle associated genes in mantle cell lymphoma: a genotypic and phenotypic study of cyclin D1, p16, p15, p53 and pRb.

Mantle cell lymphomas (MCL) are morphologically and immunophenotypically distinctive lymphoid neoplasms characterised by overexpression of cyclin D1. Recent studies have suggested that co-operating aberrations of cell cycle associated genes may provide a growth advantage to a tumour. To address this issue further, we investigated five typical and three aggressive (blastoid) MCL for alterations in the cell cycle regulating genes p15, p16, CDK4, Rb and p53. In 3/3 aggressive cases with cyclin D1 overexpression we found aberration of at least one additional gene. One case showed diminished expression of the retinoblastoma protein (pRb); one case harboured deletion of both p15 and p16; and one case exhibited both deletion of p16 and point mutation of p53. However, we also identified two typical cases which in addition to cyclin D1 overexpression exhibited diminished pRb expression and p15 and p16 hypermethylation, respectively. Our findings confirm and extend other recent investigations and indicate that co-operating genetic alterations of cell cycle-associated genes may contribute to the pathogenesis of MCL.

Adult↗

Randomized controlled smoking cessation study: transient increase in plasma high density lipoprotein but no change in lipoprotein oxidation resistance.

Low plasma levels of high density lipoprotein (HDL) and high levels of low density lipoprotein (LDL) as well as smoking are known risk factors in coronary heart disease. It has been suggested that oxidative modification renders LDL atherogenic. We investigated the influence of smoking cessation on plasma lipid and lipoprotein levels and on the ability of lipoproteins to resist oxidation in vitro (lag time). A total of 182 healthy smokers who smoked more than 15 cigarettes per day were randomized to stop smoking (smoking cessation group, n = 100) or to continue smoking for 4 weeks (control group, n = 82). The smoking cessation group was followed up after 26 weeks. After 4 weeks, the HDL level had increased from mean +/- SD 1.36 +/- 0.34 to 1.48 +/- 0.40 mmol l-1 (p < 0.001) in 62 successful quitters, while levels were unchanged in the control group (72 subjects in per-protocol analysis). However, after 26 weeks there was no change in HDL (1.34 +/- 0.36 vs. 1.36 +/- 0.35 mmol l-1) in 29 subjects from the smoking cessation group who fulfilled the study. Plasma levels of very low density lipoprotein (VLDL), LDL, total cholesterol, triglycerides and oxidation resistance of VLDL + LDL did not show significant changes any time during the study for either group. Thus, plasma levels of lipids and lipoproteins as well as oxidation resistance of lipoproteins seem unaffected by smoking cessation for 26 weeks.

Adult↗

Effect of smoking cessation on oxidative DNA modification estimated by 8-oxo-7,8-dihydro-2'-deoxyguanosine excretion.

BACKGROUND: Reactive oxygen species from, e.g. tobacco smoke are suggested to be involved in carcinogenesis by oxidative modification of DNA. The urinary excretion rate of the oxidized nucleoside 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) has been validated as a biomarker of the rate of oxidative DNA modification with mechanistic relation to carcinogenesis. In cross-sectional studies, the urinary excretion rate of 8-oxodG has been shown to be elevated in smokers compared with non-smokers. PURPOSE: In this randomised, controlled smoking cessation study, we investigated whether cigarette smoking per se causes oxidative DNA modification. METHODS: Of the 182 healthy smokers included, 100 were randomized to quit smoking after baseline samples had been taken, and 82 were randomized to continue usual smoking. Before the start of the study and after 4 weeks, the subjects collected 24-h urine samples that were analysed for 8-oxodG content by high-pressure liquid chromatography with electrochemical detection. The subjects randomized to smoking cessation were followed up after 26 weeks. RESULTS: Four weeks of smoking cessation resulted in a 21% decrease in 8-oxodG excretion rate (from mean +/- SD, 30.5 +/- 13.9 to 24.1 +/- 10.5 nmol/24 h, P < 0.001) in 58 quitters included in per-protocol data analysis. Sixty-five continued smokers included in per-protocol analysis showed a 9% decrease in 8-oxodG excretion rate (from 31.6 +/- 13.2 to 28.7 +/- 12.6 nmol/24 h, P = 0.026). After 4 weeks, the 8-oxodG excretion rate was 16% (95% confidence interval 4 to 28%) higher in the continued smokers than in the quitters (P = 0.0085, ANCOVA), demonstrating the effect of smoking per se. A 23% (P < 0.005) decrease in 8-oxodG excretion rate was sustained for 26 weeks in 27 quitters who completed the study. CONCLUSION: Smoking cessation significantly reduces the urinary excretion rate of 8-oxodG, giving direct and controlled evidence that cigarette smoking causes an increased rate of oxidative DNA modification. This could represent a mechanism by which tobacco smoke is carcinogenic.

8-Hydroxy-2'-Deoxyguanosine↗

Long-term survival and development of secondary malignancies in patients with acute myeloid leukemia treated with aclarubicin or daunorubicin plus cytosine arabinoside followed by intensive consolidation chemotherapy in a Danish national phase III trial. Danish Society of Haematology Study Group on AML.

In 1991 we reported the results from a prospective randomised phase 3 trial comparing 7 days continuous infusion of cytosine arabinoside (ara-C) combined with either daunorubicin (DNR) or aclarubicin (ACR) as direct i.v. injection for 3 days as induction chemotherapy (CT) for patients with de novo acute myeloid leukemia (AML) followed by early intensive consolidation CT with two alternating cycles of high-dose ara-C and two cycles of amsacrine plus etoposide, and finally 3 days of daunomycin plus 7 days of ara-C as administered for induction of remission. A total of 174 patients with de novo AML in the age group 17-65 years were included. The patients have now been followed till death or for at least 7 years, and an evaluation of the long-term survival and the risk of developing secondary neoplasms has been made. The overall survival rate 5-years after diagnosis was 23%, and after 10 years 19%. No difference was found between the two treatment regimens in overall survival or disease-free survival (DFS). For the subgroup of 99 patients who achieved complete remission after one or two induction courses, 5- and 10-year survival rates were 35% and 31% respectively, with the highest survival rates in the age group 17-39 years (57% at 5 years) as compared with 27% in patients aged 40-60 years (P= 0.007). Seven secondary neoplasms were diagnosed simultaneously with or after the diagnosis of AML indicating a standardized incidence ratio (SIR) of 3.41, (95% CI: 1.60-7.26). In three cases the secondary neoplasms were diagnosed simultaneously with the AML diagnosis and were for that reason completely unrelated to the chemotherapy administered for AML, as the psammomatous meningeoma diagnosed after only 8 months. The remaining three neoplasms which developed subsequently did not significantly exceed the expected number, with a SIR = 1.46 (0.47-4.57). Thus, no increased risk of solid tumors causally related to the intensive chemotherapy for de novo AML was observed. However, a generally increased risk of solid tumors in patients diagnosed simultaneously with the AML diagnosis seems likely. Over 20% of the patients were alive and in complete remission 5 years after the AML diagnosis, and they have a high probability of surviving the next 5-year period.

Aclarubicin↗

Lack of effect of zinc supplementation on antipyrine clearance in alcoholic liver disease.

METHODS: The effect of zinc supplementation on antipyrine clearance was evaluated in 14 outpatients with stable alcoholic liver disease, of whom nine had biopsy proven alcoholic cirrhosis. RESULTS: There was no change in antipyrine clearance after 14 days of zinc supplementation (median 12.5 vs 12.9 ml.min-1). However, a significant increase in P-prothrombin-proconvertin was found. There was a positive correlation between S-zinc and antipyrine clearance at inclusion (rs = 0.76) as well as after zinc supplementation (rs = 0.72). CONCLUSION: No effect of zinc supplementation on antipyrine clearance was found. The positive correlation between S-zinc and antipyrine clearance could be due to the confounding effect of alcoholic liver disease.

Adjuvants, Immunologic↗

Complement activation by malignant B cells from patients with chronic lymphocytic leukaemia (CLL).

It has previously been reported that the expression of the complement receptors CR1 (CD35) and CR2 (CD21) on malignant B cells in CLL is reduced compared with the expression on normal B cells, while deposition of complement C3 fragments, as a consequence of alternative pathway (AP) activation of complement, is observed on mononuclear cells from patients with B CLL. Following our demonstration that normal B cells are capable of activating the AP of complement in a CR2-dependent fashion, we have chosen to re-examine the complement-activating ability of B CLL cells in relation to their altered phenotype with respect to CR2 and the complement regulatory membrane proteins, CR1, decay accelerating factor (DAF) (CD55) and membrane cofactor protein (MCP) (CD46). Flow cytometry was used to measure expression of complement receptors and regulatory proteins on CD5+ B cells from CLL patients, as well as the deposition of C3 fragments occurring both in vivo and after in vitro AP activation. We have confirmed the reduced expression of CR1 and CR2 on CLL cells and have shown that AP activation in the presence of homologous, normal serum was reduced on B CLL cells compared with normal B cells. The degree of AP activation correlated directly with CR2 expression. In addition, we observed that CLL cells bear in vivo-deposited C3d,g, although at a significantly lower level than normal B cells.

Animals↗