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Biomedical subjects

B L Hillcoat

Publications and source records attributed to B L Hillcoat.

At least 19 recordsLinked to original sources
PubMed1993

Rectal adenocarcinoma with germ cell elements treated with chemotherapy.

A patient with adenocarcinoma of the rectum containing germ cell elements in the form of endodermal sinus tumor and choriocarcinoma is described, believed to be the first such tumor reported in the literature. The serum levels of alpha-fetoprotein and human chorionic gonadotropin were markedly elevated. The source of the markers was localized to the neoplastic tissue by the immunoperoxidase technique. The patient developed extensive hepatic metastases thought to be due to choriocarcinoma for which she received chemotherapy. One wk after commencing treatment a massive fatal hepatic hemorrhage occurred.

Adenocarcinoma↗
PubMed1992

cis-bis(pyridine)platinum(II) organoamides with unexpected growth inhibition properties and antitumor activity.

The platinum(II) organoamides [Pt(NRCH2)2L2] (L = pyridine (py), R = p-HC6F4, C6F5,p-IC6F4,p-CIC6F4,p-C6F5C6F4; L = 4-methylpyridine, R = p-HC6F4) and [Pt(NRCH2CH2NR')(py)2] (R = p-HC6F4, R' = C6F5, p-BrC6F4, or p-MeC6F4) inhibit the growth of murine L1210 leukemia cells in culture with ID50 values for continuous exposure in the range 0.6-2.7 microM. Representative complexes are also active against L1210 cells in 2-h pulse exposures, as well as against the cisplatin-resistant variant L1210/DDP and human colonic carcinoma cell lines HT 29 and BE. Three complexes [Pt(NRCH2)2L2] (R = p-HC6F4, C6F5, or p-IC6F4) have good activity (T/C greater than or equal to 180%) against P388 leukemia in mice, and all other compounds tested are active except when R = p-C6F5C6F4, L = py. Although the molecular basis of the biological activity of these complexes is not known, the observation of good activity for amineplatinum(II) compounds with no hydrogen substituents on the nitrogen donor atoms introduces a new factor in the anticancer behavior of platinum(II) complexes.

Animals↗
PubMed1990

Pharmacokinetic study of doxifluridine given by 5-day stepped-dose infusion.

Doxifluridine (5'-deoxy-5-fluorouridine, 5'-dFUR) metabolism has been reported to be saturable and associated with a fall in clearance of the drug as the dose is increased. The aim of the present study was to determine the disposition of 5'-dFUR and 5-fluorouracil (5-FU) when 5'-dFUR was given as a 5-day infusion, with the infusion rate increased stepwise every 24 h. Measurement of plasma and urinary levels of 5'-dFUR and 5-FU at steady state for each infusion rate enabled the estimation of 5'-dFUR renal (ClR) and nonrenal (ClNR) clearance and 5-FU renal clearance. A total of 28 patients with histologically proven malignancy received 5-day courses of 5'-dFUR ranging in dose from 3.75 to 20 g/m2 per 120 h. The lowest dose given over 24 h was 0.25 g/m2, and the highest was 5 g/m2. Steady-state plasma levels of 5'-dFUR ranged from 167 to 6,519 ng/ml. At these plasma levels there was no evidence of significant saturation of 5'-dFUR metabolism; steady-state plasma levels of 5'-dFUR increased approximately linearly with dose, and nonrenal clearance did not change significantly with dose. There was also no evidence of nonlinearity in 5'-dFUR renal clearance. The mean (+/- SD) ClR of 5'-dFUR was 108.9 +/- 53.6 ml/min per m2 (range, 45.7-210 ml/min per m2), and the ClNR was 728 +/- 181 ml/min per m2 (range, 444-1,119 ml/min per m2). Renal clearance comprised 13% of the total 5'-dFUR clearance. The mean renal clearance of 5-FU was 100.8 +/- 48.6 ml/min per m2 (range, 23.5-198 ml/min per m2). There was considerable interpatient variability in 5'-dFUR renal and nonrenal clearance, even at the same dose level. We concluded that the administration of 5'-dFUR by the infusion method described avoided the saturation of nonrenal elimination processes reported to occur with shorter infusion schedules.

Adult↗
PubMed1990

A phase I study of doxifluridine as a five-day stepped-dose continuous infusion.

Doxifluridine (5'-dFUR) is a prodrug of 5 fluorouracil (5-FU) synthesized in an attempt to improve the therapeutic index compared with 5-FU. In this phase I study, cohorts of three patients were treated by a 5-day continuous infusion with the dose increased daily, total doses ranging from 3.75 g/m2 to 20 g/m2/120 h. Twenty-nine patients received 54 courses (median 2, range 1-4). The dose-limiting toxicities were mucositis (Miller grade 3 in three patients and grade 4 in another) and grade 4 neutropenia and thrombocytopenia in two patients. Other toxicities included nausea, vomiting, and diarrhea, rash, and fever. Neurological toxicity was mild and no cardiovascular toxicity was recorded. Plasma and urine levels of 5'-dFUR and 5-FU were quantitated by high-performance liquid chromatography. Steady-state plasma levels between 167 ng/ml and 6,519 ng/ml were recorded and at these levels there was no evidence of saturation of doxifluridine metabolism. One patient at the maximum tolerated dose of 20 g/m2/120 h had a complete response in a nasopharyngeal carcinoma.

Adult↗
PubMed1989

Metallothionein induction in mouse tissues by cis-dichlorodiammineplatinum(II) and its hydrolysis products.

cis-Dichlorodiammineplatinum(II) (cis-DDP) doubled the amount of metallothioneins (MTs) in the livers and kidneys of BALB/c mice when injected i.p. in a single high dose of 30 mumol/kg (9 mg/kg). Two such doses given 17 h apart increased hepatic MTs 5-fold and also increased the relative rate of incorporation of radiolabelled cyst(e)ine into hepatic MTs. Hydrolysed cis-DDP was more effective than cis-DDP, increasing MT-bound zinc 27-fold and [3H]cysteine incorporation 6-fold in liver while doubling each of these in kidney. The MTs from the livers of mice treated with cis-DDP bound zinc, copper and platinum in ratios of 5:1:0.3, respectively, similar to those in whole liver and its soluble fraction, indicating that MTs do not selectively sequester platinum under these circumstances. The effects of cis-DDP on zinc and copper levels in serum, liver and kidney suggest that induction of MTs by cis-DDP is not mediated by displacement of endogenous zinc. Indirect induction by corticosteroids secreted in a stress response to cis-DDP is also an unlikely cause. cis-DDP, probably in a hydrolysed form, can therefore induce and bind to MTs in normal tissues, particularly when given at repeated high dosage.

Animals↗
PubMed1989

Development of a murine gastric distension model for testing the emetic potential of new drugs and efficacy of antiemetics.

A small animal model for emesis would allow preclinical testing of antiemetics and new drugs. Mice treated with cisplatinum develop stomachs distended with food. This effect is reduced by metoclopramide and parallels the gastric nausea experienced by patients receiving cisplatinum. To assess gastric distension as a more general model for paralleling the human emetic response, groups of five BALB/c mice were given intravenous nitrogen mustard, adriamycin, cyclophosphamide, 5-fluoruracil (5FU), vincristine and intraperitoneal DTIC at doses equivalent to those used clinically (mg/kg mouse = 12 X mg/kg per man). The mice were allowed free access to food pellets and water. At 48 h they were sacrificed and gastric distension quantitated as a ratio of average stomach to body weight. Significant gastric distension occurred with nitrogen mustard, DTIC, adriamycin and cyclophosphamide but not 5FU or vincristine. This parallels the emetic potential of these drugs in humans. Similarly cisplatinum was compared to its analogues, carboplatin and JM40 and produced gastric distension at lower doses than carboplatin. The model was then used to test the antiemetic efficacy of escalating doses of prochlorperazine against cisplatinum induced gastric distension in groups of 10 BALB/c mice. Doses ranged from 2.5 mg/kg. Only a high dose (19.2 mg/kg) significantly reduced the gastric distension. This parallels a clinical dose response relationship recently reported for prochlorperazine and suggests the further potential use of this model.

Animals↗
PubMed1989

Priorities in experimental therapeutics--a surfeit of riches.

Experimental therapeutics plays a key role in determining which areas of basic biological research are developed to see if they can be of use in cancer medicine. The recent expansion in our basic knowledge about biology and cancer makes difficult the choice of what areas should be developed. Six such areas are reviewed and assessed. Several hold the promise of improving the management of cancer. More important, developmental therapeutics itself adds to our basic knowledge of cancer and this in turn may indicate those areas which, if developed, will lead to cure of this disease.

Humans↗
PubMed1989

A dose finding study of prochlorperazine as an antiemetic for cancer chemotherapy.

This phase I study determined the maximum tolerated dose of prochlorperazine when used as an antiemetic prior to cytotoxic chemotherapy. Initially, cohorts of three patients were given prochlorperazine at escalating doses of 0.2, 0.4, 0.6, 0.8, 1.0 and 1.2 mg/kg as an intravenous infusion over 20 min. The maximum tolerated dose was 1.2 mg/kg. The dose-limiting toxicity was hypotension which was reversed by a fluid load. The other major toxicities were extrapyramidal reactions which were dose related. All patients at the 1.2 mg/kg dose reported restlessness while five of six were restless and two of six at 1.0 mg/kg had muscle spasms. Two of seven patients reported restlessness at the 0.8 mg/kg level. Sedation and dry mouth were reported at all dose levels but were more common at higher doses. Prochlorperazine in plasma was assayed by high performance liquid chromatography with electrochemical detection and pharmacokinetics were determined for three patients at the 1.0 mg/kg dose level. The average terminal elimination half life was 7.6 +/- 0.4 h, plasma clearance 27 +/- 5 ml/min/kg and volume of distribution 17.7 +/- 4.5 l/kg. The dose of prochlorperazine recommended for further studies of antiemetic efficacy is 0.8 mg/kg intravenously.

Antiemetics↗
PubMed1989

A randomized trial of cisplatin versus cisplatin plus methotrexate in advanced cancer of the urothelial tract.

One hundred eight patients with recurrent or metastatic transitional cell carcinoma of the urothelial tract were randomized to receive cisplatin (C) 80 mg/m2 on day 1 every 4 weeks, or methotrexate (M) 50 mg/m2 on days 1 and 15 plus C 80 mg/m2 on day 2 every 4 weeks (C + M). Fifty-three eligible patients were randomized to C + M and 55 to C. In the C + M arm, 45% of patients responded (complete response [CR], 9%) and 31% (CR, 9%) in the C arm (P = .18). In the C arm, 20 patients failing or relapsing after C received M. Two patients responded, and four with progressive disease (PD) and one with a previous partial response (PR) showed no change. The median survival was 8.7 months (C + M arm) and 7.2 months (C arm), P = .7. Relapse-free survival was not significantly different, but C + M was associated with a significantly increased time to disease progression (median, 5.0 months, v 2.8 months for C arm). The response of untreated patients (37%) was not different from those with prior treatment (39%). On the C + M arm, 92% of patients and 96% of patients on the C arm received 85% or more of the scheduled C dose. Significantly more grade 3 or 4 hematological toxicity (27% v 2%; P = .01) and mucositis (20% v 0%; P = .0005) occurred in patients on the C + M arm. Although the initial response rates seen on the combination arm look superior, and the time to disease progression is increased, these effects have not translated into a clinically important increase in the duration of survival and were associated with increased toxicity.

Adult↗
PubMed1988

Cisplatin plus VP 16-213 in advanced ovarian carcinoma.

Thirty-five patients with advanced epithelial ovarian carcinoma (24 untreated, 11 previously treated with alkylating agents) were treated with a combination of cisplatin and etoposide (VP16-213). Tumor response (i.e., complete response and partial response) was seen in 16 of the 35 patients (i.e., 46%), with 5 complete responses. The response rate in previously untreated patients was 54%, but only 27% in previously treated patients. The median survival was 42 weeks. The toxicity of this regimen was severe. Twelve patients became severely myelosuppressed, including one septic death while severely neutropenic. Treatment with cisplatin and etoposide produces only average tumor response rates and patient survival, but is associated with severe toxicity. There is no evidence of synergy between cisplatin and VP16 in this study.

Adult↗
PubMed1987

The binding of binuclear platinum(II)-terpyridine complexes to DNA.

The binding of platinum (II)-terpyridine complexes to DNA was studied by using equilibrium dialysis. Optical absorption methods were used to measure the ability of the ligands to aggregate in aqueous buffer. Scatchard plots for the binding of the monomeric [Pt(terpy)SC4H9]+ cation to DNA at I0.01 are curvilinear, concave upwards, suggesting two modes of binding. The association constant decreases at higher ionic strengths, consistent with polyelectrolyte theory, and 1.1 cations are released per bound ligand molecule. The association constants of the binuclear ligands [Pt(terpy)S[CH2]4S(terpy)Pt]2+ and [Pt(terpy)S[CH2]6S(terpy)Pt]2+ are 8 and 23 times larger respectively than the affinity of the monomer. For the latter binuclear derivative the increase may be ascribed to bifunctional reaction. Differential dialysis experiments with DNAs of differing base composition show that [Pt(terpy)SC4H9]+ has a requirement for a single G X C base-pair at the highest-affinity site. However, in the binuclear ligands chromophore specificity is severely compromised. Similar experiments indicate that 9-aminoacridine and selected methylene-linked diacridines show no significant sequence selectivity.

Animals↗
PubMed1987

Pharmacokinetics of unchanged carboplatin (CBDCA) in patients with small cell lung carcinoma.

The disposition of the cisplatin analogue carboplatin was studied in seven patients with small cell lung cancer. Carboplatin 100 mg/m2 was administered without hydration by a 1-h infusion with VP16-213 120 mg/m2 on days 1, 2 and 3 of each course. Plasma and urine collections were made on days 1 and 3 of the first course of treatment. Carboplatin levels in plasma ultrafiltrate and urine were quantitated using a specific and sensitive, high-performance liquid chromatographic assay which involved sample clean-up on a Dowex-2 column prior to injection. Estimates of pharmacokinetic parameters determined using either compartmental or non-compartmental methods were comparable. There was no difference between carboplatin pharmacokinetic parameters determined on days 1 and 3 of treatment. The mean (+/- SD) carboplatin half-life determined from plasma data on day 1 was 105 +/- 30.4 min and was not significantly different from that determined using urinary excretion rate data (107 +/- 51.7 min). Urinary excretion rate plots showed that carboplatin elimination was mono-exponential for up to 14 h after infusion. Total-body clearance was 105 +/- 40.0 ml min-1 m-2, renal clearance 64.3 +/- 44.1 ml min-1 m-2, and volume of distribution 17.3 +/- 4.2 l/m2 on the 1st day of treatment. Of the administered dose, 58.4% +/- 21.2% was recovered in urine over a 24-h period after the start of the infusion. The mean renal clearance of carboplatin was comparable to creatinine clearance. Carboplatin disposition was clearly defined in the patients studied using analytical methodology specific for the unchanged drug.

Adult↗
PubMed1987

Mitomycin and mitoxantrone in previously treated patients with advanced breast cancer.

A total of 56 heavily pretreated patients with advanced breast cancer were treated with the combination mitomycin and mitoxantrone. Partial responses were seen in ten of 56 patients (18%), or ten of 44 (23%) completing two courses, while 18 (32%) had stable disease. Responses were seen in eight patients failing doxorubicin. The median duration of response was 26 weeks, with responders surviving a median of 37 weeks. A total of 59% of the courses were associated with World Health Organization grade 3 or 4 neutropenia (less than 1.0 X 10(9) cells/L). Nausea and vomiting were minimal. Mitomycin and mitoxantrone has activity in heavily pretreated patients with advanced breast cancer.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1987

Randomized, double-blind, cross-over study comparing prochlorperazine and lorazepam with high-dose metoclopramide and lorazepam for the control of emesis in patients receiving cytotoxic chemotherapy.

To further define optimal combinations of antiemetics, high-dose metoclopramide and lorazepam (M+L) were compared with prochlorperazine and lorazepam (P+L) in a randomized, double-blind, cross-over study. Both patient and observer assessments were documented in 66 patients receiving cisplatin and noncisplatin chemotherapy. M+L significantly reduced the severity of vomiting (P = 0.01), duration of vomiting (P = 0.05), and number of vomiting episodes (P = 0.003). Comparing the severity or duration of nausea, M+L and P+L were not significantly different. M+L significantly reduced severity of vomiting (P = 0.005) and number of vomiting episodes (P = 0.03) in the cisplatin subset. The number of vomiting episodes was also reduced in the noncisplatin subset (P = 0.03). When asked to nominate a preferred regimen, 41% of patients preferred P+L, 35% preferred M+L, and 24% rated them equally. M+L was associated with significantly more anxiety and less sedation than P+L. Patient assessments produced similar results to observer assessments but gave a broader understanding of our patients' tolerance to chemotherapy. M+L is a superior regimen in controlling vomiting induced by chemotherapy.

Adult↗
PubMed1986

Binuclear platinum (II)-terpyridine complexes. A new class of bifunctional DNA-intercalating agent.

A series of binuclear DNA-binding ligands was prepared by linking two (2,2':6',2"-terpyridine)platinum(II) moieties via alpha omega-dithiols of the type HS-[CH2]n-SH where n = 4-10. A monomeric analogue was also synthesized. Compounds were characterized by elemental analysis and electronic and n.m.r. spectroscopy. Viscometric measurements with sonicated rod-like DNA fragments and covalently closed circular DNA were performed to investigate the mode of binding of these agents. The ligands with n = 5 and 6 function as bis intercalators and form a single 'base-pair sandwich' in violation of neighbour-exclusion binding. Bifunctional reaction occurs for the ligand with n = 7, whereas the ligands with n = 8 and 10 show a preference for mixed monofunctional/bifunctional binding. The data do not permit definitive assignment of the binding mode of the ligands with n = 4 and 9. All compounds are growth-inhibitory against mouse leukaemia L1210 cells in culture with IC50 values in the range 2-14 microM.

Animals↗
PubMed1985

Phase II trial of VP-16-213 in advanced ovarian carcinoma.

We have reevaluated the effectiveness of VP-16-213 in advanced ovarian carcinoma. Twenty-five patients with measurable disease were treated for 3 days every 2 weeks with an escalating dose of the oral preparation. Twenty-two percent of 23 evaluable patients responded including one complete response. The median duration of response was 20 weeks and median survival 32 weeks. Toxicity was mild. The response rate observed is relatively high in patients pretreated with cis-platinum. VP-16-213 deserves further study, especially in combination with cis-platinum.

Administration, Oral↗