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B Angus

Publications and source records attributed to B Angus.

At least 55 records · Page 3Linked to original sources
PubMed1998

Rosetting characteristics of uninfected erythrocytes from healthy individuals and malaria patients.

Rosetting, defined as the binding of two or more uninfected red blood cells (rbc) to an infected rbc, occurs when malarial parasites mature, to trophozoites and schizonts, in the second half of their asexual development. Rosetting is believed to be an important factor in the development of cerebral malaria. In a series of studies to examine the characteristics of the uninfected rbc which contribute to rosetting, the ability of rbc from healthy donors to form rosettes was found to be greater in the cells of group A and B than in those of group O (P = 0.05), and to decrease during storage under blood-blank conditions. Normal rbc exposed for > or = 30 min to quinine, artesunate or artemether (each at 0.25 microgram/ml) in vitro showed significantly decreased rosetting. This effect could not be reversed by extensive washing followed by cultivation for another 24 h in drug-free medium. Mefloquine and pyrimethamine had no effect. Uninfected rbc from patients with uncomplicated or severe falciparum malaria exhibited a lower rosetting ability than rbc from healthy donors (P = 0.01). The rosetting of uninfected rbc of all blood groups from patients with uncomplicated malaria decreased significantly within 2 h of the patients starting treatment with qinghaosu derivatives (artesunate or artemether) and within 8 h of them starting quinine treatment. Similar effects were observed with uninfected rbc from patients with severe malaria after treatment with artesunate but not after quinine. The mechanisms underlying this potentially beneficial effect on rbc adherence are not known.

ABO Blood-Group System↗
PubMed1998

Hodgkin's disease: a population-adjusted clinical epidemiology study (PACE) of management at presentation. Northern Region Lymphoma Group.

Between January 1991 and December 1993, all newly-diagnosed patients with Hodgkin's disease in the Northern Health Region (population 3.08 million) were entered into a prospective population-based (PACE) study to assess the accuracy of staging at diagnosis, and to evaluate treatment and outcome. On histological review, 202 patients were confirmed to have Hodgkin's disease, an incidence of 2.2 per 100,000 per annum. Radiological review revealed that only 12% of patients were staged to recognized guidelines. In early-stage disease, treatment outcome was comparable to published results in Stage IA disease, but disappointing for Stage IIA. This was partly due to inadequate or inaccurate staging. In-built audit in the process was followed by the introduction and implementation of improved guidelines. Of younger patients (15-55 years) with 'poor-risk disease', 75% of the eligible population were entered into the appropriate randomized controlled trial. This intensive treatment has led to improved survival in this group over that which might be expected on four-drug therapy. The results of the randomized trial are not discussed as it is currently ongoing. This combined research/audit programme has resulted in greater standardization of care across a whole region, and confirms that the PACE (population-adjusted clinical epidemiology) approach facilitates the flow of information from research into practice and vice versa.

Adolescent↗
PubMed1998

The role of alternative splicing of the adhesion molecule, CD44, in lymphoid malignancy.

AIM: To investigate the expression of CD44 isoforms containing variant exon 6 (v6) in a well characterised cohort of patients with non-Hodgkin's lymphoma (NHL) and chronic lymphocytic leukaemia (CLL), and to correlate this with phenotype and disease course. METHODS: Cryostat sections of OCT embedded diagnostic nodal material from NHL patients and cryopreserved mononuclear preparations from CLL patients were used as sources of RNA. After reverse transcription, PCR was carried out with amplimers positioned at either side of the variant exon insertion site to amplify all possible CD44 isoforms. Those isoforms containing v6 were identified after Southern blotting and hybridisation with a radiolabelled oligonucleotide. RESULTS: Of 32 NHL samples analysed, 16 did not express CD44 isoforms containing v6, six expressed an isoform containing exon v6 alone, and 10 expressed v6 long isoforms which contained exon v6 in addition to other variant exons. These data did not correlate with lymphoma classification, disease staging, or the presence or absence of extranodal disease. However, those patients expressing v6 long CD44 isoforms had a worse overall survival than those that did not. The plateau of the survival curves was 50% compared with 82%. No v6 long isoforms were detected in the 21 CLL samples investigated. CONCLUSIONS: The expression of v6 long CD44 isoforms is associated with aggressive disease in NHL, independent of grade, stage, or presence of extranodal disease.

Alternative Splicing↗
PubMed1998

New monoclonal antibodies to the T cell antigens CD4 and CD8. Production and characterization in formalin-fixed paraffin-embedded tissue.

We have generated a recombinant protein representing part of the CD4 molecule and a peptide representing an epitope of predicted high antigenicity on the CD8 molecule and employed these to generate mouse monoclonal antibodies using standard hybridoma protocols. The extracellular domain of the CD4 molecule was obtained by reverse transcription of mRNA from peripheral blood lymphocytes followed by polymerase chain reaction. The amplified gene fragment was cloned into an expression vector to allow a histidine-tagged fusion protein to be produced in Escherichia coli. Purified fusion protein was used to immunize mice. The CD8 monoclonal antibody was raised against a peptide consisting of 13 amino acids within the carboxyl-terminal region of the CD8 cytoplasmic domain. The antibodies showed appropriate reactivity on Western blotting. By heat pretreatment, these antibodies have been shown to be highly effective on paraffin-embedded tissue. In normal lymphoid tissue, the expected distribution of CD4 and CD8 lymphocytes was observed. In a series of 16 T cell lymphomas and B cell lymphomas, immunostaining results were compared with those obtained using reagents effective only in frozen tissue. A high degree of correlation was observed. These results suggest that NCL-CD4 and NCL-CD8 may be of value in the characterization of T cell disorders.

Antibodies, Monoclonal↗
PubMed1997

Determination of HLA-A*02 antigen status in Hodgkin's disease and analysis of an HLA-A*02-restricted epitope of the Epstein-Barr virus LMP-2 protein.

There is good evidence for an association between Epstein-Barr virus (EBV) and Hodgkin's disease (HD). In approximately one-third of cases, the EBV genome is detectable in Reed-Sternberg (RS) cells and there is expression of the viral nuclear antigen EBNA-1 and the latent membrane protein LMP-1. Expression of LMP-2 has been demonstrated at the mRNA level, and it is presumed that the protein is expressed alongside LMP-1. The LMP-2 protein is known to contain an epitope presented to cytotoxic T-cells which is restricted through the HLA class I antigen A*0201 in healthy seropositive individuals. Since most HLA-A*02-positive Caucasians are HLA-A*0201-positive, it was hypothesized that HLA-A*02-positive individuals would be under-represented among Caucasians with EBV-associated HD. HLA-A*02 status was determined, using flow cytometry and/or the polymerase chain reaction, for 276 individuals including 176 cases of HD. There was no significant difference between the frequency of HLA-A*02 positivity in HD cases and controls, and between EBV-associated and non-associated cases of HD. The A*02 alleles of 14 cases of EBV-associated HD were further subtyped using nested PCR; all except one case were found to be A*0201-positive. We therefore investigated whether there was any evidence for mutation of the epitope representing amino acids 426-434 of LMP-2a which is restricted through HLA-A*0201. In 10/11 cases the nucleotide sequence encoding this epitope was identical to the published sequence; in the remaining case there was a mutation which would not be expected to alter the conformation of the epitope. Overall, our data suggest that other mechanisms of immune escape must be operative in EBV-associated HD.

Adolescent↗
PubMed1997

The pathological and biological nature of screen-detected breast carcinomas: a morphological and immunohistochemical study.

Traditional and immunohistochemical markers of prognosis were examined in 455 mammary carcinomas derived from breast cancer screening and compared with those of 277 carcinomas presenting symptomatically over the same period. Tumours detected by population screening under the U.K. National Health Service Programme do not differ from those detected by other screening projects, but compared with symptomatic cancers, screen-detected cancers are more likely to be in situ and if invasive, to be smaller, of lower grade, and to have invaded vessels, perineural spaces, and lymph nodes less frequently. Tubular and cribriform types are more often represented in screened patients. Immunohistochemical markers which have been proposed as being related to likely tumour behaviour (epidermal growth factor receptor, c-erbB-2 protein, oestrogen and progesterone receptors, cathepsin D, p53, and retinoblastoma protein) do not distinguish screen-detected from 'clinical' cancers. It is concluded that cancers diagnosed at screening do not differ biologically from those presenting clinically, but are the same lesions detected at an earlier stage of their natural history.

Biomarkers, Tumor↗
PubMed1997

New monoclonal antibodies to oestrogen and progesterone receptors effective for paraffin section immunohistochemistry.

Assessment of oestrogen and progesterone receptors (ER and PgR) in breast cancer is widely used for the prediction of response to endocrine therapy and as a prognostic marker. Cytosolic assays have been replaced in many centres by immunochemical techniques, which have many advantages including applicability to small samples, simplicity, and cost-effectiveness. This study describes the generation and characterisation of two novel murine monoclonal antibodies recognizing ER and PgR, designated NCL-ER-6F11 and NCL-PGR respectively, which are effective in heat-treated formalin-fixed, paraffin-embedded tissue. The antibodies have been characterized by Western blotting and by immunohistochemistry on normal and pathological breast and other tissues. NCL-ER-6F11 has been shown to compare favourably with a currently available ER antibody. These antibodies may prove of value in the assessment of hormone receptor status in human breast cancer.

Antibodies, Monoclonal↗
PubMed1997

CHOP-based chemotherapy is as effective as alternating PEEC/CHOP chemotherapy in a randomised trial in high-grade non-Hodgkin's lymphoma. Scotland and Newcastle Lymphoma Group.

The aim of this study was to test whether survival for patients with high-grade non-Hodgkin's lymphoma (NHL) can be improved with a non-cross-resistant regimen as compared to a CHOP-based regimen. This is a multicentre study comprising 325 adult patients, median age 58 years, with high-grade non-Hodgkin's lymphoma: patients of any age and performance status were eligible provided they were able to receive the drugs in the regimens. Patients were randomised to either B-CHOP-M (bleomycin, cyclophosphamide, doxorubicin, vincristine, prednisolone and methotrexate) or PEEC-M (methylprednisolone, vindesine, etoposide, chlorambucil and methotrexate) alternating with B-CHOP-M. At a median follow-up of 9 years, there was no significant difference in overall survival or disease-free survival between the two arms. Toxicities for the two regimens were equivalent. This study confirms that for relatively unselected patients with high-grade non-Hodgkin's lymphoma, an alternating multidrug regimen does not improve upon the results obtained with B-CHOP-M.

Adult↗
PubMed1997

Alpha interferon gene deletions in post-transplant lymphoma.

Post-transplant lymphoproliferative disorder (PTLD) is a well-recognized complication of organ transplant and has been associated with high mortality using conventional chemotherapy. We have investigated 11 cases of PTLD for alterations to the interferon alpha (IFNA) and p16 genes on chromosome 9p using archival material. 4/9 (44%) cases had deletions of the IFNA genes, in contrast to 1/59 (1.7%) cases of intermediate/high-grade de novo NHL drawn from the same geographical region. PTLD may therefore represent a distinct NHL subgroup exhibiting distinct gene pathology.

Chromosomes, Human, Pair 9↗
PubMed1997

Production and characterization of a new monoclonal antibody effective in recognizing the CD3 T-cell associated antigen in formalin-fixed embedded tissue.

Phenotypic analysis of lymphoproliferative disorders is now considered mandatory for accurate classification which is the basis for optimum patient management. This is presently carried out in most cases using a range of antibodies recognizing B and T-cell antigens effective in paraffin sections, and an antibody to CD 3 is currently a key member of such panels, indicating T-cell phenotype. Current antibodies to CD3 are polyclonal with the inherent disadvantages of this type of reagent compared to monoclonal antibodies. In this study, we have used a recombinant fusion protein representing part of the epsilon subunit of the CD3 molecule to generate a novel monoclonal antibody (NCL-CD3-PS1) effective in paraffin sections. The antibody has been characterized biochemically and by immunohistochemistry using a wide range of normal and pathological tissues. Lineage and phenotype specificity have been supported in our study and results from other laboratories are awaited with interest.

Antibodies, Monoclonal↗
PubMed1997

A novel quantitative immunoassay system for p53 using antibodies selected for optimum designation of p53 status.

AIM: To develop a highly sensitive and specific enzyme linked immunosorbent assay (ELISA) system for analysis of p53 protein in cancer lysates. METHODS: The anti-p53 monoclonal antibodies DO7, 1801, BP53.12, and 421, and anti-p53 polyclonal antiserum CM1 were assessed by immunohistochemistry and western blot analysis to identify those most suitable for determining p53 status of cancer cells. Antibodies with desired characteristics were used to develop a non-competitive sandwich type ELISA system for analysis of p53 expression in cancer cytosols. Using the ELISA, p53 protein concentrations were measured in a small series of breast cancers, and the quantitative values compared with p53 immunohistochemical data of the same cancers. RESULTS: DO7 and 1801 gave the most specific and reliable results on immunohistochemistry and western blot analysis. Using these two antibodies, a non-competitive sandwich type ELISA system was developed to analyse p53 quantitatively. Analysis of the breast cancer series showed a good correlation between immunohistochemistry and the ELISA-tumours were generally positive using both techniques. Discrepancies were noted however: some cancers were immunohistochemically negative but ELISA positive. One explanation for this may be that the ELISA is more sensitive than immunohistochemistry. CONCLUSION: The p53 ELISA system is a non-competitive double monoclonal antibody sandwich method, using DO7 and 1801 which have been shown to be highly specific for p53 protein by immunohistochemistry and western blot analysis. The lower threshold of the assay is 0.1 ng/ml analyte in an enriched recombinant p53 preparation. As p53 is now regarded as a protein associated with prognosis in breast and other cancers, the assay may have clinical applications.

Antibodies, Monoclonal↗
PubMed1997

Overexpression of protein kinase C-alpha and -beta isozymes by stromal dendritic cells in basal and squamous cell carcinoma.

Protein kinase C (PKC) isoenzymes transduce signals from cell surface receptors and thereby regulate important cellular functions in skin including keratinocyte growth and differentiation. Overexpression of individual PKC isoenzymes results in aberrant cell growth and in certain instances tumorigenicity. PKC is implicated in tumour promotion in mouse skin. Abnormal expression of PKC has been reported in several human cancers. We have, therefore, investigated expression of PKC-alpha and -beta in basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) by immunohistochemistry. Sections were stained with specific antibodies to PKC-alpha, PKC-beta, CD1a, T cells, B cells and dermal dendritic cells (factor XIIIa), using an immunoperoxidase technique. PKC-alpha and PKC-beta were not detected in tumour cells in BCCs or SCCs. In SCCs, PKC-beta immunostaining revealed positively stained inflammatory and dendritic cells scattered through the stroma; PKC-alpha immunostaining was essentially negative. In contrast, in BCCs, PKC-alpha+ and PKC-beta+ dendritic and spindle-shaped cells were observed in the stroma, immediately adjacent to the tumour islands. Double-labelling experiments showed that a proportion (approximately 20%) of PKC-beta+ dendritic cells also expressed factor XIIIa. BCCs depend on stroma for growth; PKC regulates expression of type IV collagenase and stromelysin III and interactions between tumour and stroma may be important in determining tumour invasion and metastasis. Therefore, overexpression of PKC-alpha and -beta by stromal dendritic cells in BCCs suggests that PKC activation may be involved in stromal/tumour interactions in these tumours.

Basal Cell Carcinoma↗
PubMed1997

The use of fluorescent in situ hybridization for detection of the t(2;5)(p23;q35) translocation in anaplastic large-cell lymphoma.

BACKGROUND: Anaplastic large-cell lymphoma (ALCL) is a recently recognized, distinctive type of non-Hodgkin's lymphoma characterized by anaplastic large-cell cytology and expression of a member of the TNF-receptor family CD30. A characteristic chromosomal translocation has been identified in ALCL of T-or null-cell lineage which juxtaposes a novel tyrosine kinase (anaplastic lymphoma kinase, ALK) located at 2p23 with the nucleophosmin gene (NPM) at 5q35. A chimeric mRNA transcript is produced, and the translocation results in constitutive expression of a truncated form of the ALK protein, p80. There is controversy concerning whether or not the translocation occurs in Hodgkin's disease. The aim of this study was to develop a methodology for fluorescent in situ hybridization (FISH) to detect the t(2;5)(p23;q35), and to compare the results with conventional cytogenetics, reverse-transcriptase PCR and immunostaining for the p80 protein. PATIENTS AND METHODS: Twenty-five cases of malignant lymphoma (11 ALCL and 14 HD) were studied. Immunohistochemistry was performed to confirm the diagnosis and for analysis of p80 expression. Conventional cytogenetics were analyzed on G-banded metaphase spreads. FISH was performed using whole chromosome paints for chromosomes 2 and 5 on metaphase spreads and YAC probes for interphase nuclei. Reverse-transcriptase PCR using primers for ALK and NPM was used to amplify the translocation breakpoint in extracted mRNA. RESULTS: Among 11 cases of ALCL examined by FISH, the translocation was detected in 4. Two of these cases also had RT-PCR and p80 staining performed, with positive results. Among 7 cases where the t(2;5) was not detected by FISH, 3 cases were examined by RT-PCR with negative results and 4 cases by p80 staining, also negative. The RT-PCR was negative in all 14 cases of Hodgkin's disease, 4 of which were also examined by FISH and found to be negative. CONCLUSION: Fluorescent in situ hybridization is a useful method for detection of the t(2;5)(p23;q35) in anaplastic large-cell lymphoma. The results concur with those of RT-PCR for the chimeric transcript and immunostaining for the p80 protein. The frequency with which the translocation was found was 36% in this small series, and no evidence of the translocation was found in cases of Hodgkin's disease.

Antigens, Neoplasm↗
PubMed1996

Retinoblastoma protein in human breast carcinoma: immunohistochemical study using a new monoclonal antibody effective on routinely processed tissues.

Cyclic phosphorylation/dephosphorylation of the retinoblastoma gene product (pRB) has been found to play a central role in the progression of the normal cell cycle, through modulation of the activity of the E2F family of transcription factors. Mutations of the retinoblastoma gene have been described in a wide variety of human malignancies including carcinomas of the breast. The present investigation reports the production and application of a new monoclonal antibody in an immunohistochemical study of pRB expression in 233 primary breast carcinomas, allowing an assessment of the contribution made by this tumour suppressor gene to tumour development and progression. Overall, there was loss of pRB expression in 21 per cent of breast tumours. Although high-grade tumours were found to lack detectable pRB more frequently than low-grade tumours, the difference did not prove statistically significant. In addition, pRB immunostaining was not related significantly to relapse or survival. No significant correlations were observed between apparent loss of pRB and tumour size, parity, patient lymph-node status, p53, c-erbB-2, c-jun, EGFR or steroid hormone receptor expression. Preliminary findings, however, did suggest a relationship between pRB expression and response to endocrine therapy.

Adult↗
PubMed1996

p53 protein as a prognostic indicator in breast carcinoma: a comparison of four antibodies for immunohistochemistry.

We examined the reactivity of four p53-specific monoclonal antibodies--PAb 1801, p53-BP-12, D07 and CM1--on sections of formalin-fixed tissue collected from 245 breast carcinomas. Immunodetection of p53 varied between 37.6% and 46.6%. The greatest variation was observed among lobular carcinomas and low-grade tumors in which immunodetection varied between 8.3% and 27.3%. In contrast, immunodetection of p53 in invasive ductal carcinomas was subject to a lower degree of variability with between 40.6% and 49.7% of these tumours proving to be positive. In general, we found antibodies PAb 1801 and DO7 to be the most effective in immunolocalising p53. Immunodetection of p53 with each of the four antibodies was found to correlate strongly with tumour grade. In survival analysis, the results gained using antibody PAb 1801 proved to be of greatest statistical significance and to provide the strongest index of prognosis. A significant relationship was observed between immunodetection of p53 with each of the four antibodies and poor responsiveness to endocrine therapy. In addition, relationships were also observed between p53 immunostaining and tumour oestrogen receptor (ER) status as well as c-jun expression. We observed no correlation between abnormalities of the p53 and the Rb gene products or between elevated c-erbB-2 or epidermal growth factor receptor (EGFR) expression and immunodetection of p53.

Adult↗
PubMed1996

c-erb B-2 and p53 expression in breast cancer fine needle aspirates.

The aim of this study was to co-evaluate c-erb B-2 and p53 protein expression in breast cancer fine needle aspirates (FNA) and to compare this with histological variables and the immunohistochemical phenotype of the tumours. Furthermore, we assessed the relationship of c-erb B-2 and p53 immunocytochemical expression to tumour prognostic factors. We examined 124 breast cancer FNAs and 79 matched surgical specimens using the avidin-biotin complex (ABC) and the alkaline phosphatase immunocytochemical techniques. C-erb B-2 immunopositivity was detected in 37.9% of the FNAs, while 31.7% were positive for p53. A statistically significant correlation was observed between p53 negativity and absence of c-erb B-2 immunostaining in the FNAs (P = 0.0007). Smears from infiltrating ductal carcinomas tended to be more frequently positive for p53 (36.7%) than those from lobular carcinomas (11.7%) (P = 0.054). In matched tumour tissues, c-erb B-2 was positive in 16.7% and p53 in 19% of cases. The immunocytochemical results for both c-erb B-2 and p53 were significantly correlated with the immunohistochemical results. There was no correlation between c-erb B-2 and p53 immunostaining, in both FNAs and tissues, and patients menopausal status, tumour size, grade and lymph node status.

Adult↗
PubMed1996

Immunohistochemical expression of endothelial markers in left atrial myxomas: a study of six cases.

Vascular endothelial cells are antigenically heterogeneous and therefore it has been recommended that a range of immunohistochemical markers is employed to show the presence of cells of endothelial origin in surgical pathology. In this study we applied three monoclonal antibodies--to factor VIII-related antigen, JC70 (CD31), QBend 10 (CD34)--and Ulex europaeus agglutinin type 1 lectin (UEA-1), to six consecutive cases of left atrial myxoma. We found that JC70 and QBend 10 consistently stained myxoma cells in all their different growth patterns contrasting with factor VIII-related antigen expression and UEA-1 binding which were restricted to areas which showed morphological evidence of vascular differentiation. These findings suggest that the constituent cells of atrial myxomas show more widespread endothelial differentiation than has previously been recognized and that differences in immunohistochemical staining may reflect the maturation status of these cells.

Adult↗