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Biomedical subjects

H Sill

Publications and source records attributed to H Sill.

At least 19 recordsLinked to original sources
PubMed1997

Interferon-alpha-2C and LD ara-C for the treatment of patients with CML: results of the Austrian multi-center phase II study.

Small pilot studies of patients with CML have reported on encouraging response rates after treatment with interferon-alpha (IFNalpha) in combination with low-dose cytosine arabinoside (LD ara-C). We therefore initiated a multi-center phase II trial in order to investigate the efficacy and tolerability of this combination in newly diagnosed patients with Ph-positive chronic myelogenous leukemia (CML). Eighty-four patients were treated with IFN-alpha-2c at daily subcutaneous doses of 3.5 MU and LD ara-C added subcutaneously for 10 days every month at a dose of 10 mg/m2, following an initial reduction of WBC to less than 20 x 10(9)/l with hydroxyurea (HU). Within a median observation period of 28 (5-59) months the patients received a median of 7 (1-35) IFNalpha and LD ara-C cycles. Treatment was stopped due to side effects in 16 cases (19%) and to primary or secondary treatment failure in 38 cases (45%). In 45 patients (54%) complete hematological response (CHR) was achieved; in 39 patients (46%) cytogenetic responses including 15 (18%) complete cytogenetic responses (CHR) were observed. Median duration of cytogenetic responses was 15 months. Relapses were seen in 8/15 patients (53%) with complete cytogenetic remission (CCR), in 3/6 patients (50%) with partial cytogenetic response and in 9/18 patients (50%) with minor cytogenetic response. In conclusion, the combination of IFNalpha and LD ara-C resulted in encouraging rates of hematological and cytogenetic responses in patients with CML with low to moderate toxicity.

Adolescent↗
PubMed1997

The commonly deleted region at 9p21-22 in lymphoblastic leukemias spans at least 400 kb and includes p16 but not p15 or the IFN gene cluster.

Chromosome band 9p21-22 is one of the most common targets for deletions in cancer. The p16 tumor suppressor gene maps to this region and is inactivated in a wide variety of tumor cell lines and primary tumors. However, in some of the neoplasms with frequent 9p21 loss of heterozygosity (LOH), a structurally and functionally normal p16 is found suggesting that this gene might not be the primary or only target for inactivation. To define the smallest region of overlap of deletions at chromosome band 9p21-22 and to clarify the involvement of p16, p15 and the IFN cluster gene in lymphoblastic leukemias, we used a multiplex polymerase chain reaction to construct a detailed map of deletions at 9p21-22. We studied DNA from 30 lymphoblastic leukemia patients and nine cell lines using 10 genes/markers that map to this region, including four STS markers located between p16 and D9S171 (STS1, STS2) or between p16 and IFNalpha (STS3, STS4). We found that the size of the deletions in this region is variable and that the commonly deleted region spans at least 400 kb; it includes the p16 gene but excludes the IFN gene cluster and the p15 gene. The identification of this commonly deleted region enables a more focused search for other putative tumor suppressor gene at 9p21 which could be relevant to leukemogenesis.

Acute Disease↗
PubMed1997

Rarity of dominant-negative mutations of the G-CSF receptor in patients with blast crisis of chronic myeloid leukemia or de novo acute leukemia.

It is likely that leukemia results, at least in part, from mutations that lead to a block in the normal process of differentiation. A defined region of the cytoplasmic domain of the granulocyte colony-stimulating factor receptor (G-CSF-R) transmits signals for maturation or differentiation of myeloid progenitor cells. Mutations in this region have been found in some patients with severe congenital neutropenia (SCN) who subsequently evolved to acute myeloid leukemia (AML). To determine if mutations of the G-CSF-R are more widespread in hematological malignancies, we have investigated a total of 47 patients, including 29 patients with blast crisis of chronic myeloid leukemia (CML-BC) and 18 patients with de novo acute leukemia as well as 19 normal controls, by RT-PCR and SSCP analysis. Two point mutations were found in a single individual with secondary AML (FAB type M1). The first was heterozygous and is predicted to replace the normal glutamine at position 718 with a stop codon, leading to a truncated protein. An identical mutation has been described previously and shown to act in a dominant negative manner. The second mutation was homozygous and would substitute a lysine for the normal glutamic acid at position 785. No mutations were found in any other patient or control samples. We conclude that mutations in the cytoplasmic domain of the G-CSF-R are infrequent in CML-BC or acute leukemia but may contribute to malignant transformation in some cases.

Blast Crisis↗
PubMed1997

Deletion analysis of the p16 tumor suppressor gene in gastrointestinal mucosa-associated lymphoid tissue lymphomas.

BACKGROUND & AIMS: The molecular mechanisms responsible for initiation and progression of gastrointestinal mucosa-associated lymphoid tissue (MALT) lymphomas are largely unknown. The aim of this study was to analyze the p16 tumor suppressor gene in MALT lymphomas of the stomach and colon. METHODS: Tumor samples were obtained from 28 patients with low-grade (n = 12) and high-grade (n = 14) gastric MALT lymphomas and from 2 patients with colonic MALT lymphomas. DNA was extracted from microdissected areas with at least 80% tumor cells. To detect homozygous p16 deletions, a semiquantitative polymerase chain reaction assay was used, whereby either p16 exon 1 or exon 2 was coamplified with an unrelated sequence as internal control. RESULTS: Homozygous p16 deletions were found in 2 of 14 (14%) cases with high-grade gastric MALT lymphomas. Both patients had Helicobacter pylori-associated gastritis; however, DNA extracted from areas of gastritis showed a normal p16 complement. No deletion was found in any of the low-grade gastric or the colonic MALT lymphoma specimens. CONCLUSIONS: In a subset of gastric MALT lymphomas, homozygous p16 deletions are acquired and may contribute to the transformation from a low-grade to a high-grade malignancy.

Carrier Proteins↗
PubMed1997

99Tcm-tetrofosmin scintigraphy in Hodgkin's disease.

The aim of this study was to assess the suitability of 99Tcm-tetrofosmin (tetrofosmin) scintigraphy as a diagnostic modality in patients with Hodgkin's disease. Fourteen untreated patients with biopsy proven Hodgkin's disease (clinical stage Ia-IVb) were investigated. Post-treatment investigations were also done in 7 of the 14 patients. Focal pathological tetrofosmin uptake was seen in 42 site in the pre-treatment studies. Computed tomography identified 36 pathological regions. The tumour-to-background ratio ranged from 1.44 to 2.17 (mean 1.63). Follow-up studies demonstrated a response to treatment, in that there was a reduction in, or complete disappearance of, localized tetrofosmin uptake in regions previously pathological, and a decrease in tumour-to-background ratios. Tetrofosmin appears suitable for the localization of lymphomatous lesions, especially supradiaphragmatic ones, and for the follow-up of therapeutic response.

Adult↗
PubMed1997

Leukemic cells within skin lesions of psoriasis in a patient with acute myelogenous leukemia.

We report on an 81-year-old man with acute myelo-monocytic leukemia (FAB M4) and a long-standing history of psoriasis. Biopsy of psoriatic plaques revealed the coexistence of characteristic histopathologic aspects of psoriasis together with an infiltrate of blasts with features of myelo-monocytes, suggestive of a specific leukemic infiltrate within plaques of psoriasis. Immunohistologic stainings showed positivity of blasts for LN2 (CD74), MT1 (CD43), and lysozyme, consistent with a myeloid lineage of these cells. To the best of our knowledge, this is the first report on the association of psoriasis with myelogenous leukemia. The presence of leukemic cells within psoriatic skin plaques may be explained by non-specific recruitment of recirculating malignant cells to the skin. Alternatively, as psoriasis is an inflammatory disease involving granulocytes among other cell types, it may be hypothesized that leukemic cells retain to some extent their capability to respond to physiologic stimuli and enter the skin in response to specific chemotactic factors.

Aged↗
PubMed1996

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

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

Adolescent↗
PubMed1996

Rarity of microsatellite alterations in acute myeloid leukaemia.

We have analysed samples from 20 patients with acute myeloid leukaemia for microsatellite alterations by comparing constitutional DNA and DNA from leukaemic samples. Twelve microsatellites were amplified by PCR and investigated for novel bands, indicative of microsatellite instability, or for loss of heterozygosity. Out of 215 paired amplifications, no additional bands were observed at any locus in any of the samples analysed and loss of heterozygosity was found only as four loci from three patients. These results suggest that microsatellite alterations are very uncommon in acute myeloid leukaemia.

DNA Repair↗
PubMed1996

Mutational analysis of the p15 and p16 genes in acute leukaemias.

Recently the p16 and related p15 genes have been described as candidate tumour suppressors at chromosome 9p21. These genes have been found to be homozygously deleted at a high frequency in several types of solid tumours and also in acute lymphoid leukaemias. In order to determine whether these genes are more widely involved in haematological malignancies, we have investigated a total of 84 samples that did not have homozygous p16 or p15 deletions from patients with acute lymphoid leukaemia (n=13), acute myeloid leukaemia (n=24) and chronic myeloid leukaemia in blast crisis (n=43) as well as four haemopoietic cell lines. p15 and p16 exon 1 and exon 2 were amplified by polymerase chain reaction (PCR), analysed by single-stranded conformation polymorphism (SSCP) and subsequently by sequencing. Within the p16 gene, a G-->A polymorphism at nucleotide 436 was found in 3/80 (4%) leukaemias and the cell line HL60. This cell line had also a C-->T mutation at nucleotide 232 which causes a premature stop codon. Analysis of the p15 gene revealed a C-->A mutation within the noncoding sequence 27 nucleotides upstream of exon 2 in 10/80 (13%) cases. These data show that inactivation of either the p15 or p16 gene by point mutation is a very uncommon event in acute leukaemias.

Base Sequence↗
PubMed1996

CEOP-IMVP-Dexa in the treatment of aggressive lymphomas: an Austrian multicenter trial.

PURPOSE: This trial evaluated the efficacy, toxicity, and practicability of a new intensive chemotherapy regimen in a multicenter setting of university and community hospitals. PATIENTS AND METHODS: We tested a hybrid protocol of two non-cross-resistant regimens, cyclophosphamide, epirubicin, vincristine, and prednisolone (CEOP) and ifosfamide, etoposide (VP-16), methotrexate, and dexamethasone (IMVP-Dexa) given every fourth week, three to six times according to response, in patients with untreated intermediate- and high-grade non-Hodgkin's lymphoma. Ten Austrian centers entered 81 patients onto this multicenter trial. Eleven patients were excluded. The median age was 55 years. Twenty-six of 70 patients had stage III or IV disease. The distribution among international risk categories low, intermediate-low, intermediate-high, and high was 20%, 34%, 23%, and 23%, respectively. RESULTS: Of 70 eligible patients, 56 (80%) had a complete remission and seven (10%) a partial remission. After a median observation time of 36 months, the estimated time to relapse and overall survival rates are 67% and 72%, respectively. Age and Karnofsky index were the only independent risk factors for survival. Toxicity was primarily hematologic, with a median granulocyte nadir of 0.56 x 10(9)/L. Sixty-seven percent of patients had infections; 25.7% were severe World Health Organization (WHO) grade III or IV. There were three treatment-related deaths. CONCLUSION: CEOP-IMVP-Dexa chemotherapy is safe and feasible on a groupwide basis even when used in community hospitals. Neutropenic infections are the major complications. A 72% 3-year survival rate in patients with intermediate- and high-grade non-Hodgkin's lymphoma warrants further studies. These data are the basis for a randomized trial to compare cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) with CEOP/IMVP-Dexa.

Adolescent↗
PubMed1996

Reconstitution with Philadelphia chromosome-negative recipient haematopoiesis early after allogeneic BMT for CML.

We report a 33-year-old man with Ph chromosome-positive CML who underwent an allogeneic BMT from an unrelated donor. DNA microsatellite studies showed complete donor chimaerism immediately after BMT followed by mixed chimaerism; by day + 45 haematopoiesis was exclusively of recipient origin. Throughout the first year post-transplant all marrow metaphases were Ph negative but with non-clonal rearrangements consistent with autologous recovery. Cytogenetic relapse of leukaemia was first detected 15 months post-transplant. This case is unusual in that non-malignant stem cells of recipient origin survived the transplant and reconstituted haematopoiesis very early after BMT. Later the leukaemic cells reasserted their 'proliferative' advantage.

Adult↗
PubMed1996

Gallium-67-citrate scintigraphy of high-grade T-cell non-Hodgkin's lymphoma.

Scintigraphy with 67Ga-citrate indicated the transition of an orbital pseudotumor into a lymphoma by a distinct increase in 67Ga avidity. The patient initially presented with a pseudotumor in the right orbit that was verified by CT and MRI. It was caused by a chronic reactive lymphocytic inflammation extending from the lacrimal gland. At that time, scintigraphy was negative. Six and a half weeks later, the tumor had not responded to therapy and scintigraphy then showed a striking increase in gallium avidity. Consequently the tumor was excised and histology ultimately revealed a high-grade non-Hodgkin's T-cell lymphoma.

Adult↗
PubMed1996

Deletion analysis of the p16 tumour suppressor gene in phaeochromocytomas.

BACKGROUND AND OBJECTIVES: The molecular pathogenesis of phaeochromocytoma has not yet been fully established. The p16 tumour suppressor gene is often inactivated in a wide variety of primary human malignancies, including tumours of ectodermal origin. We have therefore examined the status of the p16 gene in a series of phaeochromocytomas. DESIGN: We studied tumour and constitutive DNA from 26 phaeochromocytoma patients. Twenty-two cases were of sporadic tumours whereas four patients had a hereditary form of the disease. Four tumours were malignant. We performed a semiquantitative multiplex PCR in which the p16 gene was coamplified with an unrelated sequence as an internal control. Standards were constructed by mixing DNA from cell lines with a known p16 status to simulate various degrees of p16 loss. Deletion of the p16 gene was determined by densitometry, measuring the ratio of intensity of the two resulting bands as an indication of the relative abundance of the two templates in the sample. RESULTS: No homozygous deletion of the p16 tumour suppressor gene was found in any of the phaeochromocytoma samples. CONCLUSIONS: We have demonstrated that the p16 gene is not deleted in sporadic, hereditary, malignant or benign forms of phaeochromocytomas, and therefore probably does not play a role in the pathogenesis of this tumour. However, because of the small number of malignant cases analysed, we cannot exclude a low frequency of p16 deletions in this subset of tumours.

Adolescent↗
PubMed1995

Homozygous deletions of the p16 tumor-suppressor gene are associated with lymphoid transformation of chronic myeloid leukemia.

The p16 gene, also referred to as MTS1, INK4, CDK4I, or CDKN2, at chromosome 9p21 has recently been described as a tumor suppressor that may be involved in a wide range of tumors. We have used a semiquantitative multiplex polymerase chain reaction assay to search for deletions of the p16 gene in 34 patients with chronic myeloid leukemia in blast crisis (CML BC), 19 patients with acute lymphoblastic leukemia (ALL), and 25 patients with acute myeloid leukemia (AML). Homozygous deletions of p16 exons were found in 5 of 10 (50%) patients with CML in lymphoid BC and in 5 (26%) ALL patients, but in only 1 (2%) case with AML. No deletions were found in CML BC of nonlymphoid phenotype. Comparison of chronic phase DNA or remission DNA with acute leukemia DNA in 5 individuals showed that the p16 deletions were acquired and not inherited, directly implicating these lesions in the pathogenesis of the disease. We conclude that functional elimination of the p16 gene, or a closely mapping gene, is involved in a significant number of patients with CML in lymphoid transformation.

Acute Disease↗