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Biomedical subjects

D W Miles

Publications and source records attributed to D W Miles.

At least 55 records · Page 3Linked to original sources
PubMed1993

Activity of type IV collagenases in benign and malignant breast disease.

Using zymography and computer assisted image analysis, we have measured the levels of type IV collagenases in biopsies from normal breast, and benign and malignant breast disease. The 92 kDa form was present in three of 11 cases of normal/benign disease, three of nine grade I tumours, four of 12 grade II tumours, but 11 of 11 grade III tumours. Mean levels were higher in grade III tumours (P < 0.0001). When the levels of 72 kDa collagenase and its active 62 kDa form were considered together, there was no difference between the benign and malignant cases (P = 0.55), but the amount of active enzyme, considered as a proportion of the 62 + 72 kDa forms, was significantly higher in malignant disease (P = 0.003). There was also a trend towards a higher proportion of active enzyme with increasing tumour grade (P < 0.0001). In situ hybridisation and immunohistochemistry studies showed that that mRNA and protein for the 92 kDa enzyme was primarily found in the tumour stroma. mRNA for the 72 kDa enzyme was also found in stromal areas. This study demonstrates a clear relationship between production of Type IV collagenases and malignant breast disease. Inhibitors of these enzymes may be of value in preventing metastatic disease.

Breast↗
PubMed1992

Induction of soluble tumour necrosis factor receptors during treatment with interleukin-2.

Interleukin-2 (IL-2) treatment induces other cytokines such as tumour necrosis factor (TNF) TNF may mediate some of the anti-tumour activity of IL-2, but conversely, may contribute to its dose limiting toxicities. Cleaved extracellular domains of the p55 and the p75 TNF receptors (sTNF-R1 and R2) bind to and inhibit the biological activity of TNF in vitro, but may also act as carrier molecules. We have assayed TNF and sTNFR-1 and 2 in the plasma of advanced cancer patients, before and during treatment with IL-2. Plasma levels of TNF in 22 patients were not significantly different from 25 normal controls, but levels of sTNFR-1 and sTNFR-2 were higher (P < 0.001). Levels of TNF and both its soluble receptors were significantly increased in 13 patients receiving IL-2 therapy. Maximum induced levels of sTNFR-1 and sTNFR-2 correlated closely with maximum induced levels of TNF (P < 0.001), but peak levels of sTNFR-1 and two were achieved 24-48 h after peak TNF. Levels of TNF and sTNF-Rs did not correlate with toxicity. Treatment with IL-2 leads not only to induction of TNF but also soluble binding proteins at levels which may modulate its biological activity.

Breast Neoplasms↗
PubMed1991

Activity and toxicity of carboplatin and iproplatin in relapsed high-grade glioma.

A total of 15 patients with relapsed high-grade glioma were treated with carboplatin (400 mg/m2) or iproplatin (300 mg/m2). All had received previous radiotherapy, and 12 had previously undergone chemotherapy. One of the ten patients treated with carboplatin and one of the five treated with iproplatin achieved a partial remission as determined by repeat computerised tomographic (CT) scan. Myelosuppression was considerable, as three patients developed grade IV neurotoxicity, which was fatal in one case. Although carboplatin and iproplatin showed activity against malignant glioma, the study was closed because of unacceptable toxicity.

Adult↗
PubMed1991

High-dose epirubicin as primary chemotherapy in advanced breast carcinoma: a phase II study.

A total of 40 patients with metastatic breast cancer were treated with 120 mg/m2 i.v. epirubicin every 3 weeks for a maximum of 10 cycles. Nine achieved a complete response and 17 showed a partial response, for an objective response rate of 65% (95% confidence interval, 47%-83%); the median duration of response was 7 months (range, 1-15 months) and median survival amounted to 13 months (range, 2-20 months). Leucopenia (grade 2 or 3) was seen in 14 patients on day 21 of the cycle. A subset of nine patients underwent blood counts on day 10, when all had marked neutropenia (less than 1 x 10(9)/l). Other toxicity was frequent and included nausea/vomiting (80%), alopecia (95%) and stomatitis (35%). Five patients showed a significant fall in cardiac output, but this reverted to normal after treatment. Epirubicin should have a role in the development of high-dose regimens for the treatment of advanced breast cancer.

Adult↗
PubMed1991

Intensive weekly chemotherapy for good-prognosis patients with small-cell lung cancer.

A weekly, intensive chemotherapy regimen has been used to treat 70 patients with small-cell lung cancer (SCLC). Forty-five patients had limited disease (LD) and 25 extensive disease (ED) with good prognostic features. The regimen consisted of cisplatin 50 mg/m2 intravenously (IV) day 1 and etoposide 75 mg/m2 IV days 1 and 2, alternating weekly with ifosfamide 2 g/m2 IV day 8 and doxorubicin 25 mg/m2 IV day 8, for a total of 12 weeks. Dose modifications were made according to defined hematologic criteria. Responding patients with limited disease subsequently received mediastinal radiotherapy. Overall response to chemotherapy was 91% with a complete response (CR) rate of 50%. Forty-five patients with limited disease (LD) achieved an overall response rate of 91% with a CR rate of 51%, and 25 patients with extensive disease (ED) achieved an overall response rate of 92% with a CR rate of 48%. Median survival for the whole group was 54 weeks (LD, 58 weeks; ED, 42 weeks). Hematologic toxicity was predictable, without the wide fluctuations in WBC count seen in conventional 3-weekly regimens. In all, one quarter of treatment courses were delayed, most frequently because of leukopenia. Dose reductions were required in 63% of cases. The average delivered dose intensity was calculated and shown to be 73% of projected. Nonhematologic toxicity was mild with nausea and vomiting being the most common. This weekly schedule of chemotherapy has proved to be active and well tolerated and is currently being compared with conventional 3-weekly chemotherapy in a randomized study.

Adult↗
PubMed1990

Mitomycin, ifosfamide and cisplatin in non-small-cell lung cancer.

Chemotherapy with mitomycin C, ifosfamide and cisplatin (MIC) is reported to produce responses of 56% and 69% in inoperable non-small-cell lung cancer (NSCLC). We evaluated the regimen in 45 similar patients who received up to six courses of 6 mg/m2 mitomycin C, 3 g/m2 ifosfamide, and 50 mg/m2 cisplatin every 3 weeks. In all, 18 patients had limited disease (LD) and 27 had extensive disease (ED). A total of 18 patients responded (40%), 9/18 with LD and 9/27 with ED; there were 4 complete responders. The median duration of response was 25 weeks, and median survival was 32 weeks (range, 2-96 weeks). Toxicity was moderate. Nausea and vomiting were controlled with i.v. dexamethasone and high-dose metoclopramide. Other toxicities included myelosuppression and alopecia. This study confirms that MIC is one of the most active regimens for treatment of NSCLC, with acceptable toxicity.

Adult↗
PubMed1989

Intensive chemotherapy with autologous bone marrow transplantation for small-cell lung cancer.

Since 1980, 75 patients with small-cell lung cancer (SCLC) have been entered into four consecutive studies of high-dose chemotherapy using autologous bone marrow transplantation (ABMT) to assist haematological recovery. In the first study, 25 patients were treated with cyclophosphamide (160-200 mg/kg) as the sole chemotherapy; in the second (26 patients), the cycle of high-dose cyclophosphamide (with or without 800-1,200 mg/m2 etoposide) was repeated as induction treatment. In the first study, response was high [14 complete responses (CR), 7 partial responses (PR)] but was not increased by repeating the cycle (15 CR, 8 PR), and survival was slightly worse in the second trial. In the third study, 15 patients were treated with doxorubicin, vincristine and etoposide for two cycles and then with 200 mg/kg cyclophosphamide. Although high-dose cyclophosphamide increased the complete response rate, the additional responses were short-lived. In the final study, an attempt was made to increase the initial CR rate by combination chemotherapy using carboplatin (400-600 mg/m2), etoposide (120 mg/m2 x 4) and either high-dose cyclophosphamide (40 mg/kg x 4) or melphalan (140 mg/m2). Although all nine patients responded, none underwent a CR. The long-term survival (up to 7 years) does not appear to be different from that in comparably selected cases treated with conventional chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1984

Plasma C-peptide levels identify insulin-treated diabetic patients suitable for oral hypoglycaemic therapy.

Plasma C-peptide levels were measured fasting and 2 h after an oral glucose load in 37 insulin-treated diabetic patients to assess their clinical value in identifying any noninsulin-dependent diabetic patients. All subjects were changed from insulin to oral hypoglycaemic therapy and followed for 3 months. Twenty patients (group A) completed the trial without requiring insulin and 17 (group B) required restabilization on insulin due to deteriorating metabolic control. Fasting and 2 h C-peptide levels were significantly higher in group A (0.11 +/- 0.09 and 0.17 +/- 0.12 nmol/l; mean +/- S.D.) compared with group B (0.02 +/- 0.03 and 0.02 +/- 0.03 nmol/l) (p less than 0.002 and p less than 0.002). The fasting C-peptide levels at 3 months (0.28 +/- 0.14 nmol/l) were also significantly higher than the fasting levels at the beginning of the study (p less than 0.002). Fasting and 2-h glucose levels were lower in group A (11.0 +/- 3.7 and 17.6 +/- 5.2 mmol/l) than in group B (14.4 +/- 6.2 and 23.1 +/- 5.9 mmol/l; p less than 0.05 and 0.02, respectively). The differences in glycosylated haemoglobin and fasting glucose levels at the start of the study and after 3 months of oral therapy were not statistically significant. Although C-peptide values overlapped in groups A and B, they were of greater value in identifying patients suitable for oral therapy than any single clinical criterion, and thus may help in identifying insulin-treated diabetic patients who may be treated with oral therapy without deterioration in metabolic control.

Adult↗
PubMed1982

Biochemical and biophysical approaches to improving the anticancer effectiveness of Ara-adenine.

Ara-C at very low dosage has been reported to decrease the host toxicity of ara-AMP or ara-A in combination with 2'-deoxycoformycin, a potent adenosine deaminase inhibitor, while increasing the toxicity to intracerebral L1210 leukemia. The possibility of increasing the selectivity of ara-A by prior administration of ara-C is explored. The importance of deoxynucleoside kinases, some of which may be cancer-induced, in obtaining selective anticancer effects is discussed. The possibility of a conformational basis for the differing degrees of selectivity and activity of various novel arabinosyl nucleosides is evaluated. The levels of cyclic nucleotides, which have opposing effects on leukemia, may possibly be manipulated to interfere with the growth of cancer cells. Approaches to minimizing major metabolic distortions, such as the progressive accumulation of dATP associated with the use of potent adenosine deaminase inhibitors and which limit the therapeutic effects of ara-A, are proposed.

Adenosine Deaminase Inhibitors↗
PubMed1981

Optical activity and electronic absorption spectra of some simple nucleosides related to cytidine and uridine: all-valence-shell molecular orbital calculations.

The circular dichroism and electronic absorption of three simple model systems for cytidine and uridine have been measured to 190 nm. The molecular spectral properties (excitation wavelengths, oscillator strengths, rotational strengths, and polarization directions) and electronic transitional patterns were investigated by using wave functions of the entire nucleoside with the goal of establishing the reliability of the theoretical method. The computed electronic absorption quantities were shown to be in satisfactory agreement with experimental data. It was found that the computed optical rotatory strengths of the B2u and E1u electronic transitions and lowest observed n-pi transition are in good agreement with experimental values. Electronic transitions were characterized by their electronic transitional patterns derived from population analysis of the transition density matrix. The theoretical rotational strengths associated with the B2u and E1u transitions stabilize after the use of just a few singly excited configurations in the configuration interaction basis and, hypothetically, are more reliable as indicators of conformation in pyrimidine nucleosides related to cytidine.

3-Deazauridine↗
PubMed1981

Salbutamol and cardiac arrhythmias.

A study was carried out in 7 patients with chronic obstructive airways disease to investigate the possibility of serious cardiovascular effects after the intravenous infusion of salbutamol. Patients received salbutamol starting at 5 micrograms/min and increasing gradually to 20 micrograms/min. There results of blood gas analysis showed that all but one of the patients were hypoxic and there was evidence of improved ventilation at the end of the first hour of infusion in most, with a mean reduction of 0.43 kPa in PaCO2. The patients' ECGs were monitored continuously before and during the infusion. There was an increase in mean heart rate, but not significant arrhythmias clearly provoked by salbutamol were seen. It is concluded that these findings indicate that any cardiovascular risks with parenteral salbutamol are negligible.

Aged↗
PubMed1980

Calculations of the circular dichroism of adenosine derivatives constrained in the syn form.

The rotational strengths of the four longer wavelength transitions, B(2u), B(1u), and the two E(1u), of adenosine derivatives constrained in the syn form have been investigated theoretically and experimentally. The theory combines a complete neglect of differential overlap version S (CNDO/S) description of the base with a generalized bond exciton method by means of a matrix method. Rotational strength wheels for these transitions showing the rotational strength as a function of the glycosidic rotational angles are presented and sector rules discussed. Similar sector rules are predicted for purine nucleoside derivatives containing the 6-amino substituent, regardless of heteroatom content at positions 1 or 3 of the base. The sector rules for the B(2u) rotational strength of purine nucleosides lacking the 6-amino substituent are strongly influenced by aza substitution. The circular dichroism spectra of 3-deazaadenosine, 8-(alpha-hydroxyisopropyl)-adenosine, and other purine nucleosides having a strong preference for the syn conformation are presented and compared with the theoretical results.

Journal Article↗
PubMed1979

Conformation of nucleosides: circular dichroism study on the syn-anti conformational equilibrium of 2-substituted benzimidazole nucleosides.

The solution conformations of 2-substituted derivatives of 1-(beta-D-ribofuranosyl)benzimidazole have been determined by circular dichroism spectroscopy in aqueous solutions. It is shown that analogs with methyl, amino, or methylamino substituents at position 2 of the benzimidazole ring (position 8 of the purine ring) have predominantly anti conformations, whereas analogs with chloro, aza, methoxy, or methylmercapto substituents have predominantly syn conformations. The preferred solution conformations of the benzimidazole nucleosides and analogous purine nucleosides are compared. The results demonstrate that the replacement of nitrogen by carbon at position 3 of the purine ring of purine (beta) nucleosides leads to important conformational consequences, which are strengthened or neutralized by substituents at position 8 of the purine ring.

Benzimidazoles↗
PubMed1979

Interferon induction: a conformational hypothesis.

The ability of polynucleotides or polynucleotide duplexes such as poly(I).poly(C) to induce interferon production is proposed to depend on the existence of certain stable glycosidic orientations. It appears that a slight increase in instability of 1--3 kcal/mole (1 cal = 4.184 J) in the conformational regions near 20 degrees, 80 degrees, and 160 degrees leads to a loss of potency with respect to interferon induction. Thus, it is proposed that, for a polynucleotide to exist in the overall conformation necessary for interferon induction, stability of glycosidic orientations near 20 degrees, 80 degrees, and 160 degrees may be necessary to confer flexibility and activity on polynucleotide structures. This proposed conformational triad of stable conformational regions essential to interferon induction is based on the results of conformational energy calculations of the glycoside rotational profiles of adenosine, 7-deazaadenosine, inosine, and 7-deazainosine, as well as the conformational properties of other purine nucleoside analogs, and on inferences derived from calculations about the conformational effect in polynucleotides of removing the 2'-OH group.

Adenosine↗