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Biomedical subjects

J A Bridgewater

Publications and source records attributed to J A Bridgewater.

9 recordsLinked to original sources
PubMed1999

Management of non-epithelial ovarian tumours.

Ovarian tumours of non-epithelial origin are less common than those of epithelial origin but must be distinguished from these as their natural history and management differ. As these tumours are rare, histological review by an expert in the field is essential. There have been no randomised trials to outline the management of these tumours and therefore this paper represents a review of descriptive data. Non-epithelial ovarian tumours, which represent approximately 50% of all ovarian tumours and approximately 25% of malignant ovarian tumours, are outlined. Lymphomas and metastatic tumours should be treated the same as when found in other sites and will not be discussed further.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1999

Comparison of standard and CA-125 response criteria in patients with epithelial ovarian cancer treated with platinum or paclitaxel.

PURPOSE: To assess CA-125 as a measure of response in patients treated with paclitaxel. PATIENTS AND METHODS: One hundred forty-four patients treated with paclitaxel derived from four different trials and 625 patients treated with platinum from two trials were analyzed using precisely defined 50% and 75% reductions in CA-125. The standard and CA-125 response rates to paclitaxel and platinum were compared. In addition, we analyzed individual patient groups in which there was a difference in response according to the two response criteria. RESULTS: Patients with stable disease as determined by standard criteria who were treated with platinum and responded according to CA-125 criteria have an improved median progression-free survival compared with patients with stable disease who did not respond according to CA-125 criteria (10.6 v 4.8 months; P<.001). Standard and CA-125 response rates for patients treated with platinum (58.93% v 61.31%, respectively) and paclitaxel (30.65% v 31.67%, respectively) were very similar, as were rates of false-positive prediction of response by CA-125 (platinum 2.2% and paclitaxel 2.9%). Responders to paclitaxel had a significantly improved progression-free survival compared with non-responders by both standard criteria (median progression-free survival, 6.8 v 2.5 months; P<.001) and CA-125 criteria (median progression-free survival, 6.8 v 3.4 months; P<.001). CONCLUSION: Forassessing activity of therapy for ovarian cancer, these data show that precise 50% or 75% CA-125 response criteria are as sensitive as standard response criteria. We propose that they may be used as a measure of response in lieu of or in addition to standard response criteria in clinical trials involving epithelial ovarian cancer. Sensitivity is maintained whether patients are treated with platinum or paclitaxel.

Antineoplastic Agents↗
PubMed1997

The bystander effect of the nitroreductase/CB1954 enzyme/prodrug system is due to a cell-permeable metabolite.

The bystander effect is an important part of tumor kill using gene-directed enzyme prodrug therapy (GDEPT). Recently, we have described a novel enzyme prodrug system using bacterial nitroreductase and the prodrug CB1954 (NTR/CB1954). We demonstrate here the presence of a cell-permeable cytotoxic activity in the conditioned growth medium of nitroreductase (NTR)-transduced cells treated with CB1954 and show that its appearance corresponds to the appearance of two metabolites of CB1954 previously identified (Friedlos et al., 1992). The degree of bystander effect and the degree of transferred cytotoxicity correlates with the level of NTR enzyme expression. Two other prodrugs for NTR show little bystander killing and do not produce detectable cell permeable metabolites. The elucidation of the mechanism of the bystander effect may allow the more effective use of NTR/CB1954.

3T3 Cells↗
PubMed1995

Expression of the bacterial nitroreductase enzyme in mammalian cells renders them selectively sensitive to killing by the prodrug CB1954.

A recombinant retrovirus encoding E. coli nitroreductase (NTR) was used to infect mammalian cells. NIH3T3 cells expressing NTR were killed by the prodrug CB1954, which NTR converts to a bifunctional alkylating agent. Admixed, unmodified NIH3T3 cells could also be killed. In contrast to the Herpes simplex virus (HSV) thymidine kinase (TK)/ganciclovir(GCV) enzyme/prodrug system, NTR/CB1954 cell killing was effective in non-cycling cells. Co-operative killing was observed when cells expressing both NTR and TK were treated with a combination of CB1954 and GCV. NTR expression in human melanoma, ovarian carcinoma or mesothelioma cells also rendered them sensitive to CB1954 killing. These data suggest that delivery of the NTR gene to human tumours, followed by treatment with CB1954, may provide a novel tumour gene therapy approach.

3T3 Cells↗
PubMed1995

The histological and immunohistochemical changes in the skin of patients with melanoma who develop changes in skin pigmentation following immunotherapy.

The histological and immunocytochemical appearances of skin with altered pigmentation from two patients receiving chemoimmunotherapy for melanoma were examined. In both patients, there was a clinical response to treatment coincident with depigmentation of skin and hair. Skin biopsies showed extensive infiltration with CD8+ and CD4+ lymphocytes rather than CD57+ in the depigmented areas suggestive of a specific MHC-related cytotoxic T-cell activity against melanocytes. In keeping with this, MHCII expression was markedly up-regulated. These observations suggest the development of a simultaneous anti-tumour and anti-melanocyte immune response stimulated by chemoimmunotherapy, possibly against the same or similar antigens.

Adult↗
PubMed1993

Malignant phaeochromocytoma and hypercalcaemia.

We describe a case of hypercalcaemia secondary to recurrent malignant phaeochromocytoma. Parathyroid-related protein (PTHrp 1-86) immunoreactivity was identified in plasma and PTHrp was identified by immunocytochemistry in tumour tissue.

Adrenal Gland Neoplasms↗