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L J Campbell

Publications and source records attributed to L J Campbell.

At least 19 recordsLinked to original sources
PubMed2006

hTERT, the catalytic component of telomerase, is downregulated in the haematopoietic stem cells of patients with chronic myeloid leukaemia.

Telomere shortening is associated with disease progression in chronic myeloid leukaemia (CML). To investigate the biology and regulation of telomerase in CML, we evaluated expression of the telomerase components, its regulators and several telomeric-associated proteins. Quantitative real-time-polymerase chain reaction (PCR) was used to compare gene expression in the CD34+/leukaemic blast cells of 22 CML patient samples to the CD34+ cell population of healthy individuals. hTERT, the catalytic component of telomerase, was downregulated in eight of 12 chronic phase (CP) patients (P = 0.0387). Furthermore, hTERT was significantly downregulated in two of three patients in accelerated phase (AP) and seven of seven patients in blast crisis (BC), P = 0.0017. Expression of hTR and telomeric-associated proteins TEP1, TRF1, TRF2, tankyrase and PinX1 was high in the majority of CP and AP patients. With the exceptions of TEP1 and hTR, expression of these factors was highest in CP and decreased during disease progression. Expression of c-Myc, a positive regulator of hTERT transcription, correlated with hTERT expression and decreased with disease progression, falling below control levels in BC. hTERT levels were increased in CP patients following successful treatment with imatinib, relative to untreated CP patients. We suggest that reduced hTERT expression directly causes the shortened telomeres observed in CML.

Adolescent↗
PubMed2002

The development and evaluation of a three-dimensional ultrasound-guided breast biopsy apparatus.

We have designed a prototype three-dimensional ultrasound guidance (3D USB) apparatus to improve the breast biopsy procedure. Features from stereotactic mammography and free-hand US-guided biopsy have been combined with 3D US imaging. This breast biopsy apparatus accurately guides a needle into position for the sampling of target tissue. We have evaluated this apparatus in three stages. First, by testing the placement accuracy of a needle in a tissue mimicking phantom. Second, with tissue mimicking phantoms that had embedded lesions for biopsy. Finally, by comparison to free-hand US-guided biopsy, using chicken breast phantoms. The first two stages of evaluation quantified the mechanical biases in the 3D USB apparatus. Compensating for these, a 96% success rate in targeting 3.2 mm "lesions" in chicken breast phantoms was achieved when using the 3D USB apparatus. The expert radiologists performing biopsies with free-hand US guidance achieved a 94.5% success rate. This has proven an equivalence between our apparatus, operated by non-experts, and free-hand biopsy performed by expert radiologists, for 3.2 mm lesions in vitro, with a 95% confidence.

Animals↗
PubMed2002

Sequential transformation of t(8;13)-related disease: a case report.

We report a case of an atypical myeloproliferative disorder with t(8;13) that presented as B-lineage acute lymphoblastic leukaemia (B-ALL). Following induction chemotherapy, the disease manifested as chronic myeloproliferative state, which responded to hydroxyurea. Terminally, the disease transformed into acute myeloid leukaemia (AML) with additional chromosomal abnormalities including monosomy 7. To our knowledge, this is the first case of this rare atypical myeloproliferative disorder with t(8;13) that presented as B-ALL and terminally transformed to AML with additional chromosomal abnormalities.

Acute Disease↗
PubMed2001

Deletions of the derivative chromosome 9 occur at the time of the Philadelphia translocation and provide a powerful and independent prognostic indicator in chronic myeloid leukemia.

Chronic myeloid leukemia (CML) is characterized by formation of the BCR-ABL fusion gene, usually as a consequence of the Philadelphia (Ph) translocation between chromosomes 9 and 22. Large deletions on the derivative chromosome 9 have recently been reported, but it was unclear whether deletions arose during disease progression or at the time of the Ph translocation. Fluorescence in situ hybridization (FISH) analysis was used to assess the deletion status of 253 patients with CML. The strength of deletion status as a prognostic indicator was then compared to the Sokal and Hasford scoring systems. The frequency of deletions was similar at diagnosis and after disease progression but was significantly increased in patients with variant Ph translocations. In patients with a deletion, all Ph(+) metaphases carried the deletion. The median survival of patients with and without deletions was 38 months and 88 months, respectively (P =.0001). By contrast the survival difference between Sokal or Hasford high-risk and non-high-risk patients was of only borderline significance (P =.057 and P =.034). The results indicate that deletions occur at the time of the Ph translocation. An apparently simple reciprocal translocation may therefore result in considerable genetic heterogeneity ab initio, a concept that is likely to apply to other malignancies associated with translocations. Deletion status is also a powerful and independent prognostic factor for patients with CML. The prognostic significance of deletion status should now be studied prospectively and, if confirmed, should be incorporated into management decisions and the analysis of clinical trials.

Adult↗
PubMed2000

Chromosome 20 deletions in myeloid malignancies: reduction of the common deleted region, generation of a PAC/BAC contig and identification of candidate genes. UK Cancer Cytogenetics Group (UKCCG).

Deletion of the long arm of chromosome 20 represents the most common chromosomal abnormality associated with the myeloproliferative disorders (MPDs) and is also found in other myeloid malignancies including myelodysplastic syndromes (MDS) and acute myeloid leukaemia (AML). Previous studies have identified a common deleted region (CDR) spanning approximately 8 Mb. We have now used G-banding, FISH or microsatellite PCR to analyse 113 patients with a 20q deletion associated with a myeloid malignancy. Our results define a new MPD CDR of 2.7 Mb, an MDS/AML CDR of 2.6 Mb and a combined 'myeloid' CDR of 1.7 Mb. We have also constructed the most detailed physical map of this region to date--a bacterial clone map spanning 5 Mb of the chromosome which contains 456 bacterial clones and 202 DNA markers. Fifty-one expressed sequences were localized within this contig of which 37 lie within the MPD CDR and 20 within the MDS/AML CDR. Of the 16 expressed sequences (six genes and 10 unique ESTs) within the 'myeloid' CDR, five were expressed in both normal bone marrow and purified CD34 positive cells. These data identify a set of genes which are both positional and expression candidates for the target gene(s) on 20q.

Antigens, CD34↗
PubMed1999

MYC amplification in two further cases of acute myeloid leukemia with trisomy 4 and double minute chromosomes.

We report two cases of trisomy 4 with double minute chromosomes (dmin): one in a woman with acute myeloid leukemia (AML), French-American-British subtype M2, the other in a man with chronic myelomonocytic leukemia. In the former case, many cells without trisomy 4 but with dmin were present, a finding not observed in previously reported cases. In both cases, fluorescence in situ hybridization studies demonstrated the double minutes to be MYC amplicons. Ten cases of AML with trisomy 4 and dmin have now been described; in the five cases investigated, the dmin have been shown to be amplified MYC gene sequences.

Acute Disease↗
PubMed1999

Secondary acute myeloid leukemia with inv(16): report of two cases following paclitaxel-containing chemotherapy and review of the role of intensified ara-C therapy.

Acute myeloid leukemia developing secondary to prior cytotoxic chemotherapy (s-AML) encompasses a range of distinct entities. We report two cases of s-AML with inv(16)(p13q22) who had prior exposure to paclitaxel. Additionally, two previously reported cases of s-AML with inv(16) had prior paclitaxel exposure raising the possibility that the taxanes may predispose to this specific syndrome of s-AML. One of our patients received escalated-dose ara-C chemotherapy, achieving a complete remission (12+ months). We therefore examined the prognosis of previously reported cases of s-AML with inv(16) and analyzed the influence of escalated-dose ara-C (>/=400 mg/m2/day). A total of 25 evaluable cases were identified, with 96% attaining CR independent of ara-C dose. The estimated median remission duration was 40 months and the median survival has not been reached (actuarial 5-year survival 52 +/- 18%). Although not achieving statistical significance, patients treated with escalated dose ara-C (n = 15) had longer remission duration and overall survival than those treated with standard dose ara-C (n = 10) (P = 0.063 and 0.20, respectively). In univariate analysis, younger age, male gender, and the presence of additional cytogenetic abnormalities were associated with a tendency towards adverse outcomes (P< 0.1). Age and gender were equally distributed between ara-C dose cohorts, but more patients treated with standard-dose ara-C had additional cytogenetic abnormalities (P = 0.048). Within the limitations of this retrospective study, this analysis suggests that, similar to de novo AML with inv(16), secondary cases may also potentially benefit from treatment with escalated-dose ara-C. This is consistent with the premise that the underlying molecular defect, rather than the presence of prior cytotoxic drug exposure, may be the most important determinant of disease behavior and chemotherapy responsiveness in AML.

Adenocarcinoma↗
PubMed1999

Report and abstracts of the Sixth International Workshop on chromosome 9.

A meeting on chromosome 9 was held on Tuesday, 27 October 1998 in Denver, with 38 participants (see appendix). Since the last meeting several of the positional cloning efforts on chromosome 9q have come to fruition, and the most detailed discussion was on 9p. Dr Ian Dunham from the Sanger Centre explained the strategy to be used for sequencing chromosome 9, and encouraged collaboration in the preparatory mapping. He indicated that some priority could be given to those regions where people in the field had a strong interest and could identify relevant PAC clones. At this short meeting it was clearly not possible to construct a comprehensive map of chromosome 9, and it was decided that efforts should be made to maintain links to sources of information on the chromosome 9 web page (http:@www.gene.ucl.ac.uk/chr9/). The discussions at the meeting are summarized in four sections: 9p, 9cen-q31, 9q32-9q34 and comparative mapping. Many of the posters presented at the meeting were also presented at the ASHG meeting (28-31 October 1998). They are listed here and are published in The American Journal of Human Genetics, vol. 63 (supplement). Abstracts for posters presented only at this meeting are appended to this report.

Animals↗
PubMed1999

Correlation of cytogenetics, BCR-ABL PCR studies and fluorescence in situ hybridisation (FISH) in adult acute lymphoblastic leukaemia.

BACKGROUND: Philadelphia positive (Ph+) acute lymphoblastic leukaemia (ALL) accounts for 11-29% of adult ALL. Reverse transcriptase polymerase chain reaction (RT-PCR) for the BCR-ABL fusion mRNA has identified patients with the fusion mRNA without cytogenetic evidence of the 9;22 translocation. The reason for discrepancies between cytogenetic and molecular diagnoses is unclear. AIM: Our aim was to study cases of ALL with discordant cytogenetic and RT-PCR results and identify any reasons for such discrepancies. METHODS: Laboratory records were scanned for cases of ALL tested by both RT-PCR and cytogenetics and positive by either for the 9;22 translocation. Fluorescence in situ hybridisation (FISH) was used to study discordant results where a specimen was available. RESULTS: We identified 15 patients with ALL who had both cytogenetic and RT-PCR studies for BCR-ABL. Seven had discordant results; five patients had positive RT-PCR studies with normal (four/five) or abnormal but Ph negative cytogenetics (one/five), and two were Ph+ but RT-PCR negative. FISH, using Vysis LSI bcr/abl translocation probes, showed fused signals in 12% interphase cells but not in metaphase cells in one specimen with normal cytogenetics, and 6% interphase cells in the Ph negative patient with abnormal cytogenetics. This second patient subsequently relapsed with a minor Ph+ cell line derived from the Ph negative line. CONCLUSIONS: These results confirmed the need for both cytogenetics and RT-PCR to identify Ph+ ALL. FISH did not show sub-microscopic rearrangements of BCR-ABL in normal metaphases. Failure to identify the Philadelphia chromosome cytogenetically appeared due rather to Ph+ cells failing to divide.

Adolescent↗
PubMed1997

Frequent loss of heterozygosity in early non-small cell lung cancers at chromosome 9p21 proximal to the CDKN2a gene.

Deletions involving the chromosome 9p21 region have been reported as frequent events in non-small cell lung cancer (NSCLC). To investigate potential tumor-suppressor gene (TSG) loci within the 9p21 region, which also harbors the candidate TSG locus CDKN2a, we studied 32 cases of primary NSCLC for loss of heterozygosity (LOH). Tumor and paired normal lung cells were microdissected from lung tissue imprints and all samples screened using PCR-LOH analysis with 15 9p markers. In addition, 3 NSCLC cell lines and their matched normal lung and tumor DNA were similarly analyzed. LOH at the marker D9S259, which is proximal to the CDKN2a locus, was found most frequently (52%), while LOH at D9S942, the marker closest (5 kb) to the CDKN2a gene, was seen in only 17%. Homozygous loss of markers close to CDKN2a was, however, detected in 2 of the 3 cell lines and one accompanying tumor sample. We propose that a TSG in the region of deletion proximal to the CDKN2a gene within 9p21 may play a significant role in the pathogenesis and progression of NSCLC.

Carcinoma, Non-Small-Cell Lung↗
PubMed1995

Application of interphase cytogenetics to monitor bone marrow transplants.

Chromosomal in situ hybridization (ISH) has extended the scope of cytogenetic analysis to nondividing cells by the use of chromosome-specific probes detected by nonisotopic techniques. This provides a rapid and sensitive method for identifying chromosomes in interphase cells, and is useful in gauging engraftment following bone marrow transplantation, particularly when the number of cells obtained is minimal. We have performed ISH using a Y-heterochromatin-specific probe to monitor patients with malignant hematological disease who have received a sex-mismatched transplant. The results have been compared with those obtained from concurrently performed standard cytogenetic analysis. Host cells were detected by interphase cytogenetics in all patients posttransplant, at times varying from 28-1,825 days, whereas routine analysis detected host cells in only 4 patients, 3 of whom were found to be in relapse. The significance of the persistence of host cells is unknown, but it does not appear to indicate impending relapse.

Adolescent↗
PubMed1995

New translocation t(2;13)(p12;q34) and rearrangement of the MLL gene in a childhood leukemia cell line.

Here we report the case of a 7-month-old boy who presented with biphenotypic acute leukemia, but with leukemia cells of B-cell phenotype present at the time of relapse. Two cell lines were derived from bone marrow specimens obtained at relapse, and immunophenotyping and analysis of antigen receptor gene configuration revealed concordance between the patient's leukemic cells and the cell lines. Cell line PER-377 shows a new chromosomal abnormality, t(2;13)(p12;q34), a molecular rearrangement at chromosome band 11q23 in the absence of a cytogenetically detectable abnormality of this band, and deletion of the genes for IGK.

Biomarkers, Tumor↗
PubMed1994

Homozygous and hemizygous deletions of 9p centromeric to the interferon genes in lung cancer.

Cytogenetic analysis has indicated that deletion of chromosome 9p occurs in a significant number of non-small cell lung and mesothelioma tumors. Using paired oligonucleotide primers, we have undertaken an extensive analysis of 9p markers to determine homozygous and heterozygous loss of marker sequences. Homozygous loss of D9S169 and D9S171, both of which map centromeric to the IFN gene cluster, were noted in three cell lines (27%) and hemizygous deletions of one or both of these loci was found in a further six cell lines (54%). These data suggest the presence of a potential tumor suppressor gene for lung cancer in proximity to D9S169 and D9S171 at 9p21.

Carcinoma, Non-Small-Cell Lung↗
PubMed1994

Localization of a human receptor tyrosine kinase (ETK1) to chromosome region 3p11.2.

We have recently described a human receptor tyrosine kinase (hek) that is expressed by some pre-B and thymic T cell lines, but is not detectable on normal adult human tissues. Gene cloning studies established that hek is a new member of the EPH family of receptor tyrosine kinases. The expression of hek may normally be developmentally regulated and inappropriate expression may contribute to oncogenesis. In the present study, we have used Southern blot analysis of somatic cell hybrids and fluorescence in situ hybridization to localize the hek gene to human chromosome region 3p11.2. Karyotype analysis of the cell lines that over-express hek showed no cytogenetically visible abnormality involving the hek locus.

Animals↗
PubMed1994

The prognostic significance of deletion of the long arm of chromosome 20 in myeloid disorders.

A review of patients with myeloid disorders presenting to a large cytogenetic referral centre over a ten year period was undertaken to assess the clinical relevance of the presence of del(20q) in their malignant karyotypes. Twenty-six patients were identified, four with myeloproliferative disorders (MPD), 15 with myelodysplastic syndromes (MDS) and seven with acute leukemia. The presence of del(20q) in four patients with MPD did not appear to adversely affect survival, with all patients alive 18 to 184 months post diagnosis. However, the 15 patients with MDS had a median survival of only 12 months. Seven of these patients developed acute leukemia including three of four patients with refractory anemia with ringed sideroblasts (RARS). Of the seven patients with acute leukemia de novo and del(20q), six were treated with only two achieving complete remission. The median duration of survival for these seven patients was 5 months. These results, when compared with published survival data from the MIC Cooperative Group, indicated that del(20q) in MDS is associated with a high rate of transformation to acute leukemia and a poor prognosis. In de novo acute leukemia, del(20q) is associated with a poor response to treatment and reduced survival.

Acute Disease↗
PubMed1993

Validating a compendium of goals and objectives for educating CNS students in ambulatory care.

In fall 1990, the Department of Veterans Affairs launched a Pilot Ambulatory Care and Education program that has as its major goal the shift from a traditional inpatient specialty-based focus of patient care and health professional education to a more forward-looking outpatient generalist-based focus of care and education. The generalist and specialist focus of the CNS role has been introduced in this innovative ambulatory care program. Formal and informal educational opportunities for interdisciplinary team members and students abound. This article describes the development and validation of a compendium of goals and objectives for educating CNS students in ambulatory care.

Ambulatory Care↗
PubMed1992

Marrow proliferation and the appearance of giant neutrophils in response to recombinant human granulocyte colony stimulating factor (rhG-CSF).

During a study of recombinant human granulocyte colony stimulating factor (rhG-CSF) administration, 15 patients received twice daily i.v. infusions and nine patients received daily s.c. infusions of rhG-CSF for 5 d prior to cytotoxic therapy, and then a second course subsequent to melphalan administration. There was a striking dose-related neutrophilia and the appearance in the blood of early myeloid cells that express the intercellular adhesion molecule CD54. In addition, giant neutrophils or macropolycytes were observed in the peripheral blood of all patients. These cells were evident on the display of the Technicon H*1 as a population of large peroxidase positive cells, and using Feulgen staining these cells were shown to be tetraploid. Bone marrow kinetics studies performed on Day 4 or 5 indicated an increase in the proportion of bone marrow cells in S phase, G2 and mitosis, reflecting a proliferative response of the marrow. Large myeloid precursors and occasional binucleate promyelocytes were seen in the bone marrows done on Days 14 and 18 but not on Day 5. These findings indicate that administered G-CSF has both quantitative and qualitative effects on myeloid cells in vivo.

Bone Marrow↗