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Biomedical subjects

R T Oliver

Publications and source records attributed to R T Oliver.

At least 73 records · Page 4Linked to original sources
PubMed1997

Testis cancer.

Although the concept that transplacentally acting estrogen-mimicking chemicals damage fetal germ cells is still the most favored hypothesis to explain the link between declining sperm counts and rising testis cancer, there has been increasing recognition that other mechanisms may be contributing. With reports confirming the association between a sedentary lifestyle and rising incidence of testis cancer and a fourfold increased relative risk of delay in conception of more than 3 months found for those driving a vehicle for more than 3 hours a day, there is increasing recognition that heat may be one of the most important cofactors. The role of p53 in heat-mediated damage and deficiency of heat shock protein response of germ cells and germ cell cancer are providing increasing interest in the search for molecular mechanisms to explain the unique chemosensitivity of this group of tumors. Perhaps the most controversial report was the finding of mutations insufficient to block apoptosis in 67% of tumor p53 genes using a RNA-SSCP analysis, when only a quarter of them had mutations identified by conventional DNA sequencing. The acceptance that immunosuppression, whether HIV- or chemically induced, increases risk of germ cell cancer by 20 to 50 times that in the general population is perhaps the most important final confirmation of the immune-surveillance hypothesis, although there is no evidence as yet that it seriously worsens the chance of long-term cure in these patients. Further progress is being reported on the use of high-dose chemotherapy and stem-cell transplants, although the risks of treatment-related mortality still restrict its use to second line treatment. The problem of patient consent to the increasing range of options for early-stage disease is something highlighted from reports over the past year that will undoubtedly be an important issue in the future.

Biomarkers, Tumor↗
PubMed1997

Randomized trial of bleomycin, etoposide, and cisplatin compared with bleomycin, etoposide, and carboplatin in good-prognosis metastatic nonseminomatous germ cell cancer: a Multiinstitutional Medical Research Council/European Organization for Research and Treatment of Cancer Trial.

PURPOSE: This prospective randomized multicenter trial was designed to evaluate the efficacy of carboplatin plus etoposide and bleomycin (CEB) versus cisplatin plus etoposide and bleomycin (BEP) in first-line chemotherapy of patients with good-risk nonseminomatous germ cell tumors. PATIENTS AND METHODS: Between September 1989 and May 1993, a total of 598 patients with good-risk nonseminomatous germ cell tumors were randomized to receive four cycles of either BEP or CEB. In each cycle, the etoposide dose was 120 mg/m2 on days 1, 2, and 3, and the bleomycin dose was 30 U on day 2. BEP patients received cisplatin at 20 mg/m2/d on days 1 to 5 or 50 mg/m2 on days 1 and 2. For CEB patients, the carboplatin dose was calculated from the glomerular filtration rate to achieve a serum concentration x time of 5 mg/mL x minutes. Chemotherapy was recycled at 21-day intervals to a total of four cycles. RESULTS: Of patients assessable for response, 253 of 268 (94.4%) of those allocated to receive BEP achieved a complete response, compared with 227 of 260 (87.3%) allocated to receive CEB (P = .009). There were 30 treatment failures in the 300 patients allocated to BEP and 79 in the 298 allocated to CEB (log-rank chi 2 = 26.9; P < .001), which led to failure-free rates at 1 year of 91% (95% confidence interval [CI], 88% to 94%) and 77% (95% CI, 72% to 82%), respectively. There were 10 deaths in patients allocated to BEP and 27 in patients allocated to CEB (log-rank chi 2 = 8.77; P = .003), which led to 3-year survival rates of 97% (95% CI, 95% to 99%) and 90% (95% CI, 86% to 94%), respectively. CONCLUSION: With these drug doses and schedules, combination chemotherapy based on carboplatin was inferior to that based on cisplatin. This BEP regimen that contains moderate doses of etoposide and bleomycin is effective in the treatment of patients with good-prognosis metastatic nonseminoma.

Adult↗
PubMed1996

Long-term follow-up of gonadotrophin-releasing hormone analog treatment for recurrent endometrial cancer.

To test the antitumor effect of gonadotrophin-releasing hormone (GnRH) analogs, 32 consecutive patients with recurrent endometrial cancer that had progressed through conventional treatments were entered into an open observational trial of treatment with this class of compounds. Patients recruited had progressive, symptomatic, and measurable disease. Treatment was with monthly subcutaneous injections of GnRH analog. Measurements of gonadotrophins, sex hormones, and tumor dimensions were made together with repeat biopsy when possible to assess response to treatment. An objective response was seen in nine patients (28%, 95% CI 13-43%). Responses were seen within the first 2 months of treatment and included pelvic as well as distant sites of recurrence. Significantly greater response rates were seen in previously irradiated sites when compared with nonirradiated sites of recurrence (0.01 > P > 0.001). There was no significant difference between the response in patients with G3 lesions compared with patients with G1/G2 lesions (P > 0.5). Response did not correlate with previous progestogen exposure. No evidence of disease flare or drug toxicity was observed. GnRH analogs have a significant and durable antitumor effect in recurrent endometrial cancer which warrants further examination in comparison with progestogens.

Adult↗
PubMed1996

Testis conservation studies in germ cell cancer justified by improved primary chemotherapy response and reduced delay, 1978-1994.

OBJECTIVE: To investigate the need for the continued encouragement of early diagnosis of germ cell cancer of the testis, in view of the prevailing cure rate of 95%. PATIENTS AND METHODS: The study comprised a retrospective review of 453 unselected and previously untreated patients referred to one centre between 1978 and 1984, comparing the delay from first symptoms with the histological diagnosis. RESULTS: With a delay of < 30 days, 20% of patients had overt metastases at presentation and if the delay was > 4 months. 55% had metastases (chi-squared trend = 15.9, P < 0.001); 18% of Stage-1 patients under surveillance with a delay of < 30 days relapsed, compared with 38% of those with a delay of > 4 months. During the period 1978-1983, 16% of patients were seen after a delay of < 60 days, during the period 1984-1988 the proportion was 22% and during 1989-1994, 31% (chi-squared trend = 8.2, P < 0.004). There was a non-significant trend for a more prolonged delay in those aged < 21 years and > 40 years. Thirty-two patients had chemotherapy with the primary tumour in situ; at orchidectomy, 13 of 18 had no viable malignancy and four of five with viable malignancy also had drug-resistant metastases. Fourteen did not undergo orchidectomy; within a median follow-up of 9 years, one developed a second (histologically different) tumour after 12 years. The outcome of preliminary attempts to use neoadjuvant chemotherapy with or without partial orchidectomy for patients with tumours in a solitary testis is discussed. CONCLUSION: These findings clearly justify the continued encouragement of early diagnosis, possibly best performed as part of an extended educational programme of genital health at puberty. The long-term potential for testis conservation should be explored initially in tumours in a solitary testis.

Adult↗
PubMed1996

Testicular cancer.

The rising rate of germ cell cancer of the testis over the past decade has been demonstrated to be occurring predominantly in the younger age group (15 to 19 years) in association with earlier onset of puberty and earlier onset of regular sexual activity. Chemicals and viruses, with their atrophogenic effect, remain the main candidates for inducing the final common pathway of tumor development and clonal evolution, ie, gonadotropin-driven mitosis in spermatogonia. The possibility of different genetic mechanisms regulating susceptibility and resistance to these two extreme causes of gonadal atrophy in families is raised by the failure of a genome screen in a series of sibling pairs with testicular cancer to identify a single significant linkage group. Studies demonstrating high levels of non-mutated p53 protein and rapid induction of apoptosis by chemotherapy provide a new insight into the cause of the exquisite chemosensitivity of these tumors. Durable responses to paclitaxel and in vitro activity in response to temezolamide provide further evidence of the plethora of agents that work against these tumors, although no new first-line therapeutic approaches have been reported recently. The most important clinical trial studied good-risk patients and demonstrated that to gain the benefit of reducing treatment time from 12 to 9 weeks it is essential to retain bleomycin in the BEP (bleomycin, etoposide, and cisplatin) regimen. The final new idea to emerge recently comes from a series of papers on management of primary tumors in patients with a solitary testis and the possible use of organ-conserving surgery plus postoperative radiation. Another study did suggest it might be possible to use preoperative chemotherapy in those wishing to retain spermatogenesis.

Adolescent↗
PubMed1996

Comparison of immunological changes between subcutaneous and intravenous route of administration of IL-2 in cancer patients.

The effects of the route of administration of interleukin 2 (IL-2) on the immunological parameters of patients with various malignancies were investigated. The percent mean values for IL-2 receptor (Tac) positive cells among mononuclear cells in patients receiving IL-2 subcutaneously (5 cases) or intravenously (6 cases) were 7 and 7%, respectively. The corresponding values of post-IL-2 treatment peak were 18 and 16%. Similarly, the values for class II antigen expressing cells were 12 and 16% and 25 and 26%. In no case the difference between the values for the subcutaneous or the intravenous route reached significance. Using the 51Cr release assay, the mean percent killing activity of IL-2-activated mononuclear cells against Daudi tumour target cells for the subcutaneously and the intravenously treated groups were 27 and 14% and the corresponding values for the post-IL-2 treatment peak were 59% (p > 0.05) and 69% (p > 0.05), respectively. The similar values using K562 tumour as target were 17 and 8%, and the corresponding values for post-treatment peak were 55% (p > 0.05) and 23% (p > 0.05). In all cases the cytotoxic values for the post-IL-2 treatment were significantly greater than the pre-IL-2 values. The mean (+/- SD) values for serum beta2-m levels for 6 subcutaneously and 5 intravenously IL-2-treated patients were 6.5 +/- 4.6 and 5.7 +/- 3.4 mg/l (p > 0.05). The corresponding values for post-IL-2 (15 days) were 9.1 +/- 3.4 and 9.9 +/- 5.1 mg/1, respectively. These results demonstrate that there is no significant difference in the immunological parameters in cancer patients receiving IL-2 via subcutaneous or intravenous routes and provide further support for the current trend for clinical trials to concentrate on outpatients subcutaneous administration.

Biomarkers↗
PubMed1996

Defective expression of adhesion molecules on human bladder tumour and human tumour cell lines.

The pattern of expression of cell adhesion molecules, i.e., leucocyte function associated antigen 3 (LFA-3) and intercellular adhesion molecule 1 (ICAM-1) on human bladder tumour biopsy specimens was investigated. Attempts were also made to study the pattern of induction of these molecules by established human cell lines in response to cytokines. The results indicated that 15 of 25 tumour biopsy specimens were negative for ICAM-1, and amongst the remaining 10, only 1 showed strong positivity, whilst LFA-3 was expressed in 21 of 23 cases. Unlike LFA-3, the pattern of ICAM-1 expression on established tumour cell lines was different in that there were 7 of 21 cases showing positive staining. The parallel investigation of ICAM-1 and major histocompatibility complex class II antigen expression on bladder tumours showed that in 11 of 18 cases, there was a concomitant expression or complete absence of these molecules. In the remaining 7, there were 6 cases where only class II expression was observed. Exposure of cell lines to interferons alpha or gamma had no effects on LFA-3 expression. In contrast, interferon gamma induced ICAM-1 on all the eight lines with constitutive ICAM-1 expression, whereas interferon alpha upregulated only 2 of these 8 lines. The mean +/- SD values for ICAM-1 expression on the eight inducible lines were 617 +/- 406 cpm before and 943 +/- 471 cpm (p = 0.001) after interferon gamma stimulation. The pattern of ICAM-1 inducibility of a bladder cell line Fen to interferon remained unchanged following transfection of a beta2-microglobulin gene and correction of cell surface HLA class I antigens. These results indicate that there was a significant minority of bladder tumours and tumour cell lines with abnormal cell adhesion molecule expression. In some cases, the abnormality in cell lines could not be corrected by cytokine stimulation. It is possible that these abnormalities may play a critical role in the overall tumour strategy for escape from immunological detection.

Biopsy↗
PubMed1996

Accurate quantitative analysis of cellular proteins using a computerised scanning-aided dot blot technique.

The aim of this study was to use a dot blot technique (DB) aided by a computerised scanning programme (CSDBT) to assess expression of cellular proteins in various tumour cell lines. Two groups of proteins, i.e. major histocompatibility complex (MHC) Class I and cell adhesion molecules (e.g. ICAM-1) were investigated. The constitutive expression of Class I antigens was measured and found to vary for different tumour lines. Exposure of SKV14 (SV40 transformed epithelial cells) and 5637 lines (bladder) to interferons (IFN) alpha or gamma resulted in upregulation of Class I antigens. IFN gamma, but not IFN alpha, induced ICAM-1 on all the lines studied. Thus, the stimulatory indices (SI) for Class I antigens in the case of SKV14, J82 (bladder) and 5637 lines after IFN gamma and IFN alpha stimulation were 2.02, 1.77, 4.68 and 1.65, 1.36, 2.08 respectively. The corresponding values for ICAM-1 were 1.65, 1.87, 3.43 and 1.75, 1.0, 0.96. In all the cases, the P values (using a paired t-test), except ICAM-1 for IFN alpha-stimulated J82 cells, were below 0.05. Following exposure of cells to combinations of drugs and IFN alpha, the percentage inhibition for Class I and ICAM-1 in the case of SKV14 and 5367 lines in the presence of cycloheximide (10 micrograms/mL) were 82%, 85% and 57%, 45% respectively. The corresponding values for indomethacin (10 micrograms/mL) were -23%, -52% and -20%, -24%. In all cases, the P values (using a paired t-test) were below 0.05. To our knowledge this is the first report describing a computerised scanning programme for assessing the presence of cellular proteins. The results were consistent with those obtained by radiobinding and immunocytochemistry. This simple and sensitive approach highlighted two important issues: (a) that it can be used to detect minor changes, under various conditions, of cellular proteins whether cytoplasmic or otherwise; and (b) that the accuracy of the measurements was enhanced by the use of computer scanning.

Biomarkers, Tumor↗
PubMed1995

Super-sensitive epithelial cell line and colorimetric assay to replace the conventional K562 target and chromium release assay for assessment of non-MHC-restricted cytotoxicity.

Using colorimetric MTT assay the susceptibility of a newly established bladder epithelial cell line, Fen cells was compared with conventional target cells, i.e., K562 and Daudi and other epithelial lines for investigation of non-specific killing activity (NK/LAK) of effector cells previously activated with interleukin-2 (IL-2). The results showed that Fen cell line was more sensitive than K562 and Daudi targets and this was seen whether the effector cells were IL-2-activated or not. The percent killing of effector cells from nine normal donors against Fen, K562 and Daudi targets at effector/target (E/T) ratio of 10/1 after IL-2 activation were 63.4 +/- 7.3, 42.6 +/- 4.3 (p = 0.0001) and 38.6 +/- 5.1 (p = 0.0001) respectively. The corresponding values for inactivated effector cells at 50/1, E/T ratio were 44.8 +/- 9.0, 25.1 +/- 8.3 (p = 0.0001) and 24.4 +/- 9.4 (p = 0.0001) indicating exquisite sensitivity of Fen cells to NK/LAK killing. The susceptibility of Fen cells was found to increase by pre-treatment of target cells with interferons (IFN). Thus the percent killing of untreated, IFN-alpha (1000 U/ml), beta (2000 U/ml) and gamma (100 U/ml) treated cells were 52%, 64% (p = 0.005), 70% (p = 0.001) and 67% (p = 0.001) respectively. These results indicated that Fen cells were more susceptible to NK/LAK killing than the conventional K562 and Daudi target cells. These results and the epithelial origin of Fen cells indicate that this cell line might prove to be a more realistic system to replace the conventional approach for assessment of NK/LAK activity in patients with cancer of epithelial origin.

Cell Death↗
PubMed1995

Epidermal growth factor-induced protection of tumour cell susceptibility to cytolysis.

Using radiobinding, transfection and colorimetric assays, the biological significance of epidermal growth factor (EGF) and its receptor on established human tumour cell lines was investigated. The intensity of class I major histocompatibility antigen (MHC) and EGF receptor (EGFR) expression on 20 tumour cell lines was investigated and showed no direct correlation (coefficient of correlation r = 0.43 and P = 0.06). furthermore, transfection of the beta 2-microglobulin gene into a class I negative bladder tumour cell line, resulting in the re-expression of fully assembled cell surface class I antigens, did not result in alteration of EGFR expression. However, there was an inverse correlation between the intensity of EGFR expression and the stimulatory response of cells to exogenously added EGF. The per cent inhibitions of cell proliferation by EGF at 100 ng/ml for A431 (highest EGFR expressor) and Scaber (lowest EGFR expressor) were 37 and -7%, respectively. The results also showed that cell lines isolated from testis tumours positive for epithelial markers (using pan keratin antibody LP34 as an epithelial marker), expressed significantly lower EGFR levels than cell lines from bladder tumours. The expression of EGFR receptor was not modulated by interferons (IFN-alpha and -gamma and only a minor effect with IFN-beta) or active supernatant containing a mixture of cytokines. Whilst the pretreatment of tumour cells with IFNs resulted in a significant increase in the susceptibility of tumour cells to interleukin-2-activated peripheral blood mononuclear cells, EGF treatment resulted in their protection. Thus, the per cent killing at an effector:target ratio of 20:1 for untreated cells and EGF (100 ng/ml), IFN-alpha (1000 U/ml), -beta (2000 U/ml) and -gamma (100 U/ml) were 53%, 33% (P = 0.004), 64% (P = 0.004), 69% (P = 0.001) and 66% (P = 0.001), respectively. These results indicate the complex interactions between EGF and EGFR and their relevance in modifying tumour cell behaviour. The hypothesis that the resistance to cytolysis of tumour cells induced by EGF stimulation may be a factor in the accelerated tumour growth seen in patients after traumatic tissue damage is discussed.

Cell Death↗
PubMed1995

Accelerated cisplatin-based chemotherapy for advanced bladder cancer.

The toxicity and efficacy of accelerated cisplatin, vincristine and methotrexate was assessed in patients with advanced urothelial carcinoma. 30 consecutive patients were entered into a phase II trial and treated with cisplatin, vincristine and methotrexate given every 10 days (MOPq10) for four cycles, followed by two further cycles at 21 day intervals. Five complete responses and 14 partial responses were observed (overall response rate 63%; 95% confidence interval 45-78%). The median progression-free survival was 7.5 months (range 1.8-28) and the median overall survival 10.5 months (range 2.36). Toxicity was moderate with no treatment-related deaths. It is concluded that although the overall survival is still disappointing, the toxicity is less with the protocol than reported with methotrexate, vinblastine, doxorubicin and cisplatin (M-VAC) or escalated M-VAC (E-MVAC) and the time on treatment is shorter. MOPq10 provided palliative benefit to two-thirds of patients with advanced transitional cell carcinoma including those in their eighth decade.

Adult↗