Surgery (RMH) - Research Publications
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ItemReport of a workshop on standardization of selective cultures for normal and leukaemic cells.(Springer Science and Business Media LLC, 1977-04)
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ItemMOLECULAR AND BIOLOGICAL PROPERTIES OF A MACROPHAGE COLONY-STIMULATING FACTOR FROM MOUSE YOLK SACS(ROCKEFELLER UNIV PRESS, 1978)A colony-stimulating factor (M-CSF) has been partially purified and concentrated from mouse yolk sac-conditioned medium (YSCM). M-CSF appeared to preferentially stimulate CBA bone marrow granulocyte-macrophage progenitor cells (GM-CFC) to differentiate to form macrophage colonies in semisolid agar cultures. By comparison, colony-stimulating factor (GM-CSF) from mouse lung-conditioned medium (MLCM) stimulated the formation of granulocytic, mixed granulocytic-macrophage, and pure macrophage colonies. Mixing experiments indicated that both M-CSF and GM-CSF stimulated all of the GM-CFC but that the smaller CFC were more sensitive to GM-CSF and that the larger CFC were more sensitive to M-CSF. Almost all developing "clones" stimulated initially with M-CSF continued to develop when transferred to cultures containing GM-CSF. In the converse situation, only 50% of GM-CSF prestimulated "clones" survived when transferred to cultures containing M-CSF. All clones initially stimulated by M-CSF or transferred to cultures stimulated by M-CSF contained macrophages after 7 days of culture. These results suggest that there is a population of cells (GM-CFC) that are capable of differentiating to form both granulocytes and macrophages, but, once these cells are activated by a specific CSF (e.g. M-CSF), they are committed to a particular differentiation pathway. The pattern of CFC differentiation was not directly related to the rate of proliferation: cultures maximally stimulated by M-CSF produced mostly macrophage colonies, but the presence of small amounts of GM-CSF produced granulocytic cells in 30% of the colonies. Gel filtration, polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate, and affinity chromatography with concanavalin A-Sepharose indicated that M-CSF from yolk sacs was a glycoprotein with an apparent molecular weight of 60,000. There was some heterogeneity of the carbohydrate portion of the molecule as evidenced by chromatography on concanavalin A-Sepharose.
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ItemThe junction-associated protein AF-6 interacts and clusters with specific EPH receptor tyrosine kinases at specialized sites of cell-cell contact in the brain(ROCKEFELLER UNIV PRESS, 1999-01-25)The AF-6/afadin protein, which contains a single PDZ domain, forms a peripheral component of cell membranes at specialized sites of cell-cell junctions. To identify potential receptor-binding targets of AF-6 we screened the PDZ domain of AF-6 against a range of COOH-terminal peptides selected from receptors having potential PDZ domain-binding termini. The PDZ domain of AF-6 interacts with a subset of members of the Eph subfamily of RTKs via its COOH terminus both in vitro and in vivo. Cotransfection of a green fluorescent protein-tagged AF-6 fusion protein with full-length Eph receptors into heterologous cells induces a clustering of the Eph receptors and AF-6 at sites of cell-cell contact. Immunohistochemical analysis in the adult rat brain reveals coclustering of AF-6 with Eph receptors at postsynaptic membrane sites of excitatory synapses in the hippocampus. Furthermore, AF-6 is a substrate for a subgroup of Eph receptors and phosphorylation of AF-6 is dependent on a functional kinase domain of the receptor. The physical interaction of endogenous AF-6 with Eph receptors is demonstrated by coimmunoprecipitation from whole rat brain lysates. AF-6 is a candidate for mediating the clustering of Eph receptors at postsynaptic specializations in the adult rat brain.
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ItemEditorial(Elsevier, 1994-01-01)
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ItemEVALUATION OF TUMOR AND TISSUE DISTRIBUTION OF PORPHYRINS FOR USE IN PHOTODYNAMIC THERAPY(CHURCHILL LIVINGSTONE, 1992-03)A range of pure, monomeric porphyrins were synthesised and their localising capacities compared to HpD and Hp at 6 h and 24 h post injection in the mouse C6 intracerebral glioma model as well as in normal brain, skin, muscle, kidney, spleen, liver, lung and whole blood. The partition coefficients were examined between PBS and 2-octanol over the pH range 7.4-6.6 and pH profiles were established. A parabolic relationship was observed between log (porphyrin tumour concentration) at pH 7.4, with maximal tumour localisation at log (partition coefficient), pi, of approximately zero. Porphyrins with side chains with nett cationic character also exhibited up upward (parabolic) dependence on pi for most tissues studied, with maximal porphyrin localisation at pi of 0-0.5. In contrast, those porphyrins with nett anionic character exhibited a downward (negative) parabolic trend for all eight tissues studied, with minimal porphyrin localisation at pi of approximately zero. Four porphyrins (4, 11, 12, 13) exhibited similar or better tumour localisation than HpD, and two (11 and 12) offer promise as lead compounds for the design of improved porphyrins for use in PDT.
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ItemEVALUATION OF A MORPHOLINOTHIOLPORPHYRIN FOR USE IN PHOTODYNAMIC THERAPY(STOCKTON PRESS, 1994-09)The photonecrotic effectiveness of a morpholinothiolporphyrin derived from haematoporphyrin was measured in an animal model of cerebral glioma. The dose administered was 20 mg kg-1 and the laser dose varied from 0 to 200 J cm-2. The tumour necrosis was at least as good as that of HpD, and this therapeutic response may be attributed to the targeting of specific 'photopotent' subcellular sites.
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ItemEvaluation of porphyrin C analogues for photodynamic therapy of cerebral glioma(NATURE PUBLISHING GROUP, 1996-02)A series of monomeric porphyrins (2-8) based on porphyrin C (1) have been tested as sensitisers for photodynamic therapy (PDT) of cerebral glioma using the in vitro/in vivo C6 intracerebral animal tumour model. The in vivo screening, consisting of cytotoxicity, phototoxicity (red light) and subcellular localisation studies, revealed two sensitisers (porphyrin 7, molecular weight 863 Da and porphyrin 8, molecular weight 889 Da), which had greater photoactivity than porphyrin C and similar photoactivity to haematoporphyrin derivative (HpD) although at a 5-fold higher dose than HpD. Both sensitisers showed intracellular localisation to discrete organelle sites and exhibited considerably less 'dark' cytotoxicity than HpD. The kinetics of uptake of porphyrins 7 and 8 was studied in the mouse C6 glioma model as well as in biopsy samples from normal brain, liver, spleen and blood. Maximal drug uptake levels in tumour occurred 9 and 6 h after intraperitoneal injection for 7 and 8 respectively, at which time the tumour to normal brain ratios were 15:1 and 13:1 respectively. The effect of PDT using porphyrin 7 activated by the gold metal vapour laser tuned to 627.8 nm was studied in Wistar rats bearing intracerebral C6 glioma. At a drug dose of 10 mg porphyrin 7 kg-1 body weight and laser doses of up to 400 J cm-2 light, selective tumour kill with sparing of normal brain was achieved, with a maximal depth of tumour kill of 1.77+/-0.40. mm. Irradiation following a higher drug dose of 75 mg porphyrin 7 kg-1 body weight resulted in a greater depth of tumour kill, but also significantly increased the likelihood and extent of necrosis in normal brain.
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ItemOVEREXPRESSION OF MULTIPLE ONCOGENES RELATED TO HISTOLOGICAL GRADE OF ASTROCYTIC GLIOMA(CHURCHILL LIVINGSTONE, 1992-07)The expression of the c-erbB-1, c-myc, Ha/N-ras and c-fos oncogenes was investigated in 62 astrocytomas of low, intermediate and high grades by immunogold silver histochemistry. Elevated expression of c-erbB-1 was observed in 95%, 48% and 86% of low, intermediate and high grade tumours respectively, c-myc in 5%, 33% and 76% respectively, Ha/N-ras in 0, 43% and 71% respectively and c-fos in 55%, 48% and 52% respectively. Controls included normal brain and tumour sections immunoreacted with pre-immune serum or with antisera absorbed with synthetic peptides. Analysis of co-overexpression revealed that low grade tumours co-overexpressed a maximum of two of these genes, intermediate grade tumours a maximum of three of these genes, while co-overexpression of all four genes was observed in some high grade tumours. Co-overexpression of c-erbB-1 and c-fos was frequently observed in low grade astrocytomas and may be predictive of non-progression. On the other hand, there was a statistically significant increase in the number of tumours overexpressing Ha/N-ras or c-myc with increasing grade of tumour, suggesting that overexpression of these two oncogenes may be indicative of progression.