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J T Kemshead

Publications and source records attributed to J T Kemshead.

At least 73 records · Page 4Linked to original sources
PubMed1989

Neural cell adhesion molecule (NCAM) is the antigen recognized by monoclonal antibodies of similar specificity in small-cell lung carcinoma and neuroblastoma.

We describe reagents from 2 workshops which had been identified as recognizing the same or very similar antigens based on their tissue reactivity. Examination of their tissue specificity led us to the conclusion that this was similar to the expression of the neural cell adhesion molecule (NCAM). We also describe the use of a transfection-based assay to show that these reagents do recognize NCAM. 3T3 cells were transfected with a full-length clone of human NCAM. Indirect immunofluorescence studies showed binding of all related antibodies to the transfectants, but not to the control 3T3 cells. In addition, biochemical analysis using certain antibodies in the cluster confirm that they detect NCAM in the transfectants. Our study shows the benefits of using workshops to compare monoclonal antibodies and a molecular approach to define the antigens recognized by such reagents.

Antibodies, Monoclonal↗
PubMed1989

Differential susceptibility of HLA class II antigens induced by gamma-interferon in human neuroblastoma cell lines.

Five neuroblastoma cell lines have been examined for the induction of HLA class II antigens by a recombinant gamma-interferon. The expression of HLA-DR and -DP was induced on up to 80% of cells in two of five neuroblastoma cell lines examined (KP-N-SI and KP-N-RT). Low expression of HLA-DR and -DP was induced on the SK-N-DZ line in the presence of recombinant gamma-interferon for 10 days. In contrast HLA-DQ was not induced on any of five neuroblastoma cell lines studied. HLA-DR and -DP antigen induction was reversible, falling to nondetectable levels when interferon was removed from the culture medium. The reinduction of interferon to the culture medium again induced HLA-DR and -DP antigen expression in a fashion similar to that originally observed. These results were confirmed by Northern blot analysis using a probe to HLA-DR alpha mRNA. Recombinant interferon appears to induce HLA class II expression at the level of gene transcription or posttranscription. The results also indicate that HLA-DR, -DP, and -DQ antigens are independently regulated. Treatment of neuroblastoma cell lines with gamma-interferon results in the induction of a differentiated phenotype. Although the cytokine gamma-interferon induces neurofilament expression in some of the cell lines, this was not the case for all lines studied. Thus no correlation could be established between the morphological differentiation and either HLA class II or neurofilament expression. In addition, no correlation between response to recombinant interferon and N-myc amplification was noted. The biological significance of HLA class II expression on neuroblastoma cell lines by gamma-interferon may be related to the differentiation stage of neuroblastoma cells or may enable gamma-interferon-treated neuroblastoma cells to be recognized by cytotoxic T-cells.

Dose-Response Relationship, Drug↗
PubMed1989

Monoclonal antibodies as targeting agents for cytotoxic compounds in vivo: a current assessment.

Monoclonal antibodies have proved useful in the in vitro diagnosis of tumour type. Radiolabelled antibodies have also been investigated as targeting agents for the in vivo diagnosis of tumour metastasis. These studies have revealed the potential of using 'targeting agents' to identify tumours, but in addition have exposed some of the problems associated with the technique. This review describes our experiences using radiolabelled antibodies for the identification and treatment of tumours arising from the neuro-ectoderm. Based on a small number of 4 patients studies, we conclude that there are limitations on the use of radiolabelled antibodies for targeting isotopes to primary tumour masses. In addition, we outline a possible important role for antibodies in targeting therapeutic agents to minimal residual disease and diffuse tumours presenting as micro-metastasis.

Animals↗
PubMed1989

Bone marrow examination in neuroblastoma patients: a morphologic, immunocytochemical, and immunohistochemical study.

Bone marrow examination was performed at the time of diagnosis, before initiation of therapy, and during follow-up of 14 consecutive patients with neuroblastoma who were treated at the National Hospital in Oslo. A total of 30 bone marrow specimens were examined by conventional histology, by immunohistochemistry with selected monoclonal antibodies to neuroblastoma cells (UJ 13A, UJ 167.11, PI 153/3, and A2B5) applied on trephines, and by morphologic evaluation of smears in addition to immunocytochemistry of aspirated bone marrow cells. The study confirmed the value of immunohistochemistry and immunocytochemistry for the detection of bone marrow involvement in neuroblastoma. Immunohistochemistry performed on bone marrow trephines was a slightly better adjunct than immunocytochemistry on aspirated bone marrow cells.

Adrenal Glands↗
PubMed1989

N-myc gene expression and oncoprotein characterisation in medulloblastoma.

Although medulloblastoma and neuroblastoma share many common biological, histological and immunological features, the frequency of N-myc amplification differs markedly between the two tumours. In this study, Southern blot analysis revealed that the N-myc gene was not amplified in any of the nine medulloblastoma samples analysed. In contrast, over-expression of the gene was found in six of 11 samples as determined by immunocytochemistry and/or Western blot analysis, using an antiserum raised against a synthetic peptide representing a sequence unique to the N-myc gene product. The specificity of this reagent was demonstrated by studies on a variety of cell lines expressing N-myc and/or c-myc oncoproteins. Of the 12 medulloblastoma samples collected over a two-year period and analysed in the course of this project, a trend towards longer disease-free survival was noted in the patients having low levels of the N-myc protein in their tumour.

Blotting, Southern↗
PubMed1989

Monoclonal antibody 3F8 recognises the neural cell adhesion molecule (NCAM) in addition to the ganglioside GD2.

The monoclonal antibody 3F8 has been described as binding to the ganglioside GD2. This antibody, of the IgG3 isotype, has been used in immunotherapy, radioimmunolocalisation and targeted radiation therapy. 3F8 was originally observed to have a binding profile similar to two monoclonal antibodies, UJ13A and 5.1.H11, characterised as binding to the neural cell adhesion molecule (NCAM). This observation has also been confirmed using a hetero-antiserum prepared against purified NCAM. The cross-reactivity of 3F8 with NCAM has been confirmed by cross-blocking studies with an anti-NCAM antiserum, and by direct immunoprecipitation and gel electrophoresis. In addition, we show that 3F8 binds to human NCAM from 3T3 fibroblasts transfected with NCAM cDNA constructs. It is possible that the common epitope shared by GD2 ganglioside and NCAM involves sialic acid residues common to both the ganglioside and the glycoprotein.

Adult↗
PubMed1989

Monoclonal antibodies M340 and UJ181.4 recognize antigens associated with primitive neuroectodermal tumours/tissues.

Monoclonal antibodies UJ181.4 and M340 were raised from separate fusions using either human foetal brain or medulloblastoma tissue as immunogens. The antibodies are both of IgG isotype and bind to their target antigens with affinities in excess of 10(-9) M. Both monoclonal antibodies have been shown to bind to primitive neuroectodermal tumours and human foetal brain. Expression of the two antigens is developmentally regulated as no binding is detected on adult brain as determined by a variety of indirect binding assays. The two monoclonal antibodies can be clearly distinguished by their migration in a pH gradient (isoelectric focussing gels). UJ181.4 and M340 clearly recognize two different epitopes, as it is not possible to block the binding of one antibody with an excess of the other. In addition, careful study of the binding profiles of the two reagents suggest that they recognize two distinct antigens, although these have not been biochemically characterized. The reagents have proved particularly useful in both the differential diagnosis of the small round cell tumours of childhood and anaplastic brain tumours. In addition, they have formed part of a panel of reagents used for the immunomagnetic depletion of neuroblasts from bone marrow and have been used for targeting radionuclides to tumour cells in the intrathecal compartment.

Animals↗
PubMed1989

Phenotypic analysis of four human medulloblastoma cell lines and transplantable xenografts.

An extensive panel of monoclonal antibodies (MAb) and monospecific antisera reactive against neuroectodermal-, neuronal-, glial-, and lymphoid-associated antigens, extracellular matrix, HLA, and cell-surface receptors was used to characterize the phenotype of four continuous, karyotypically distinct medulloblastoma cell lines and transplantable xenografts. All four cell lines demonstrated significant reactivity with anti-neuroectodermal-associated MAb. No apparent pattern of reactivity with anti-lymphoid MAb was seen; notably, there was a uniform absence of detectable Thy-1. Review of the complete antibody reactivity profile revealed a dichotomy between lines TE-671 and Daoy and lines D283 Med and D341 Med, which have been previously shown to express neurofilament protein in culture and xenografts, and to exhibit neuroblastic morphological features in biopsy and xenograft tissue sections. TE-671 and Daoy reacted with the MAb directed against tenascin, epidermal growth factor (EGF) receptor, HLA-A,B epitopes, beta 2-microglobulin and 5/8 of the glioma-associated antigens, but did not react with the anti-neurofilament protein (NFP) MAb. D283 Med and D341 Med expressed NFP but did not react with MAb against tenascin, EGF receptor, HLA-A,B epitopes, beta 2-microglobulin or 6/8 and 7/8 (respectively) of the glioma-associated antigens. The observed phenotypic differences provide a conceptual framework for investigating basic differences in the biological behavior of medulloblastoma. Moreover, the subdivisions can be evaluated for prospective value in tissue diagnosis, cerebrospinal fluid cytology and antibody-mediated imaging and therapy.

Animals↗
PubMed1989

Monoclonal antibodies for detecting bone marrow invasion by neuroblastoma.

One hundred and sixty six bone marrow aspirates from children with abdominal neuroblastoma were independently examined for the presence of neuroblastoma cells by conventional haematological staining techniques and by indirect immunofluorescence using one or more of five monoclonal antibodies. Results using the two methods were evaluated by comparison with the results of bone marrow, bone and lymph node biopsy specimens taken at the same time, and in the light of the child's clinical course. One antibody, UJ13A, was found to have 98.5% specificity and 85.7% sensitivity, compared with sensitivities for conventional staining of 50% for aspirate alone and of aspirate or trephine biopsy specimen of 71.4%. The remaining antibodies UJ127/11, UJ223/8, UJ181/4 and UJ167/11, with specificities in the range 94-99%, were found to have sensitivities in the range 47-61%, lower than the sensitivity of conventionally stained aspirate or trephine biopsy specimen. Routine immunofluorescence staining with monoclonal antibody UJ13A should increase the sensitivity of detection of metastatic neuroblastoma.

Abdominal Neoplasms↗
PubMed1988

Schwannian cell differentiation of human neuroblastoma cell lines in vitro induced by bromodeoxyuridine.

In normal development the neural crest gives rise to sympathetic neuroblasts, sensory and autonomic ganglia, as well as Schwann cells. One tumor arising from this tissue is the neuroblastoma (NB), a malignancy of the adrenergic component of the sympathetic nervous system. Recent histological studies have shown that neuroblastomas can present with a schwannian cell component, rich in S100 protein. We have investigated the differentiation of NB cell lines, GOTO and RT-LN-1, into a schwannian cell phenotype using bromodeoxyuridine (BrdU). This agent induced morphological changes in these cell lines. Flat-epithelial cells were identified in the GOTO cell line and both flat-epithelial and neuronal phenotypes were found in the RT-LN-1 cell line. S100 protein (beta-Subunit) was induced in both cell lines after 18-25 days of BrdU treatment as determined by enzyme-linked immunoassay. In addition increase in the beta-subunit of S100 protein was identified in BrdU-treated flat-epithelial cells by indirect immunofluorescence using a monoclonal antibody specific for the beta-subunit of the protein. Cyclic nucleotide phosphodiesterase activity significantly increased in both BrdU-treated NB cell lines, as compared with nontreated cells. However no significant increase of glial fibrillary acidic protein in BrdU-treated cells was found either by enzyme-linked immunoassay or indirect immunofluorescence using a monoclonal antibody to glial fibrillary acidic protein. Thus, cells with Schwann cell characteristics can clearly be identified in the neuroblastoma cell lines after BrdU treatment. Fluorescence-activated cell sorting analysis revealed no quantitative changes in cell membrane antigens recognized by monoclonal antibodies UJ-13A (neuroectodermal associated antigen) and anti-Thy-1 (Thy-1) on BrdU treatment. In contrast, UJ-127-11 (neuroectodermal associated) decreased, and W6/32 and BB7.7 (HLA-ABC) and BBM.1 (beta 2-microglobulin) markedly increased in both BrdU-treated cell lines. No induction of L243 (HLA-DR), B7/21 (HLA-DP), and Genox 3.55 (HLA-DQ) was noted. The increased HLA-ABC (HLA class I) antigen may enable BrdU-treated NB cells to be recognized by cytotoxic T-cells. This may be related to the pathological evidence that NB patients whose tumors are rich in S100 protein have a better prognosis. Further studies on the potential of differentiation agents to induce a phenotypic change, that is associated with an improved prognosis for NB patients, are required.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed1988

A pilot study of 131I monoclonal antibodies in the therapy of leptomeningeal tumors.

A pilot study was performed to investigate the toxicity and therapeutic effect of radiolabeled antibody administered intrathecally in patients with leptomeningeal tumors. Five patients who failed conventional therapy received between 11 mCi and 40 mCi of radiolabeled antibody. The choice of antibody varied depending on the immunophenotype of the tumor. Therapy was well tolerated generally, with minimal acute toxicity. Four of five patients achieved an objective response to treatment that has been sustained for a period varying from 7 months to 2 years. No clinical signs of chronic toxicity have been observed in patients 1 and 2 years after therapy.

Adult↗
PubMed1988

Diagnosis of neuroblastoma metastasis in bone marrow with a panel of monoclonal antibodies.

Neuroblastoma, along with rhabdomyosarcoma, Ewing's sarcoma, and acute lymphoblastic leukemia/lymphoma, is one of the small, round-cell tumors of childhood. All of these malignancies show a propensity to metastasize to bone marrow. Occasionally when the clinical picture is unclear and the tumor is particularly anaplastic, it can be difficult to arrive at a diagnosis by conventional histological and biochemical procedures. In the present study, a panel of nine monoclonal antibodies was used to undertake a detailed analysis of seven bone marrows contaminated with tumor cells: six cases of stage IV neuroblastoma, and one case of stage IV-S neuroblastoma. The antibody profiles obtained were compared with those deduced from the studies of over 20 marrows from patients with acute lymphoblastic leukemia. A comparison of these data with those obtained from the studies of rhabdomyosarcoma and Ewing's sarcoma cell lines and tissues suggests that when high levels of tumor cells are present in the marrow, it is possible to obtain a confident diagnosis of either neuroblastoma or acute lymphoblastic leukemia. In addition, the immunocytological identification of neuroblasts in bone marrow enables accurate staging without histological examination.

Antibodies, Monoclonal↗
PubMed1988

The biodistribution and pharmacokinetics of meta-iodobenzylguanidine in childhood neuroblastoma.

MIBG is generating considerable interest for the treatment of neuroblastoma. This study has investigated the biological variation in handling of the compound in children with neuroblastoma. The biodistribution of the compound has been characterised in children undergoing tracer administrations of 123I and 131I-mIBG. Estimates of hepatic and whole body radiation dose delivery have been made. The results indicate substantial interpatient variation in hepatic dose delivery. This organ may be critical in some patients undergoing targeted radiotherapy with mIBG.

3-Iodobenzylguanidine↗
PubMed1988

Immunoglobulin gene rearrangement and antigenic profile confirm B cell origin of primary cerebral lymphoma and indicate a mature phenotype.

Six cases of primary cerebral lymphoma were immunophenotyped and analysed by Southern blotting to determine the clonality and lineage of these neoplasms. Molecular analysis showed that they were of B cell origin, and the rearrangement of both heavy and light chain immunoglobulins in malignant cells showed that they were monoclonal populations of mature B cells. The characterisation of the genetic configuration of the immunoglobulin genes in these lymphomas is important because the ability to distinguish between primary lymphoma of the central nervous system and other malignant cerebral tumours has important implications for treatment and survival.

Aged↗
PubMed1988

Immunocytochemical detection of tumours of neuroectodermal origin.

Immunocytochemical methods were applied to bone marrow aspirate and cerebrospinal fluid specimens to show cellular reactivity with the monoclonal antibody UJ13A, which recognises an antigen expressed by cells of neuroectodermal origin. The antigen remained stable after air drying and appropriate fixation. In five patients with various neuroectodermal tumours the diagnostic advantages of these techniques were clear; they can be performed even when only very small amounts of diagnostic material are available.

Adult↗
PubMed1988

Neoplastic meningitis from a pineal tumour treated by antibody-guided irradiation via the intrathecal route.

A monoclonal antibody (UJ181.4) was labelled with 131I and given intrathecally to a patient who was critically ill with neoplastic meningitis due to a disseminated pineoblastoma. The target antigen had first been demonstrated on tumour cells by immunocytological testing of cerebrospinal fluid (CSF). As a preparation for therapy, a test dose of 131I-UJ181.4 antibody was given simultaneously with a control antibody labelled with 125I. Good evidence of in vivo immunolocalization was obtained by external gamma counting and by analysis of the radiolabels on centrifuged CSF cells. Specificity ratios of between 10:1 and 20:1 were obtained by these methods. A single relatively small therapeutic dose of 131-I (870 MBq) given by the intrathecal route, resulted in a marked clinical improvement and sustained remission for 22 months.

Antibodies, Monoclonal↗
PubMed1988

A model system illustrating the isolation and enrichment of a rare population of tumour cells in bone marrow.

A model system employing a modified nylon matrix is described for the separation of rare cells titrated into either a leukaemic cell line or normal bone marrow. A 75- to 125-fold enrichment and recovery of the rare cell population was achieved, starting from an initial level of 0.014 to 0.2% of the total population. The rare cell population was identified by pre-labelling with Hoechst 33342, which intercalates into the DNA, and renders cells highly fluorescent. Separation and recovery of cells was totally dependent on the use of a panel of monoclonal antibodies binding to the labelled population. The nylon matrix, precoated with an anti-mouse immunoglobulin, traps the cells coated with monoclonal antibodies, and these can be released simply by gentle manipulation of the matrix. The matrix employed has been shown to not specifically trap committed bone marrow progenitors as determined by CFU-GM, BFU-E and CFU-GEMM assays. The use of this technique should simplify the isolation of rare tumour cells metastasizing to bone marrow.

Affinity Labels↗