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Biomedical subjects

W R Miller

Publications and source records attributed to W R Miller.

At least 109 records · Page 6Linked to original sources
PubMed1997

Endothelin expression and responsiveness in human ovarian carcinoma cell lines.

To elucidate the potential role of endothelins (ETs) as growth regulators in ovarian carcinoma cells in culture, expression of endothelins and their receptors were measured in two ovarian cancer cell lines (PEO4 and PEO14), together with the effect of the exogenous addition of endothelins on the growth of these cell lines in vitro. RT-PCR analysis of mRNA prepared from PEO4 and PEO14 indicated the presence of ET-1 and ET-3 mRNA. Immunoreactive ET-1-like peptide was found in media from cultures of both PEO4 (1.7 +/- 0.4 fmol/10(6) cells/72 h) and PEO14 (20.2 +/- 6.8 fmol/10(6) cells/72 h) cell lines. Radioligand binding studies using 125I-ET-1 and membrane fractions were consistent with PEO4 cells having two receptor sites of either high affinity (Kd = 0.065 nM, Bmax = 0.047 pmol/mg protein) or lower affinity sites (Kd = 0.49 nM, Bmax = 0.23 pmol/mg protein). Studies using membrane fractions of PEO14 cells indicated that this cell line has only a single lower affinity binding site (Kd = 0.56 nM, Bmax = 0.31 pmol/mg protein). However, RT-PCR analysis indicated the presence of mRNA from both ETA and ETB receptors in PEO4 and PEO14 cell lines. Exogenous addition of ETs to PEO4 and PEO14 cells at concentrations of 10(-10)-10(-7)M resulted in specific dose-dependent increases in cell number for ET-1 (with maximum effects at 10(-10) and 10(-9)M for PEO4 and PEO14, respectively) and ET-2 (maximum effects at 10(-8) and 10(-9)M for PEO4 and PEO14, respectively) but not for ET-3. Experiments on the growth of PEO14 cells using BQ123 (ETA-R) antagonist and "antisense" oligonucleotide against the ETA-R, in the absence of exogenous ETs, suggested that immunoreactive ET-1-like material secreted by PEO14 cells can affect their growth in an autocrine manner. These results would be consistent with ET-1 acting as a possible autocrine growth regulator in human ovarian carcinoma cells.

Cell Division↗
PubMed1997

Transforming growth factor-beta isoform expression in human ovarian tumours.

The expression patterns of members of the transforming growth factor-beta (TGF-beta) family were analysed in 96 primary ovarian tumours by RNAse protection assay. mRNA for the three mammalian isoforms, TGF-beta 1, TGF-beta 2 and TGF-beta 3, was detected in 46, 66 and 66% of 74 malignant tumours, respectively, with the predominant patterns of expression being either dual or triple co-expression. TGF-beta II receptor expression, detected by reverse-transcription PCR, was present in 92% malignant tumours. Expression patterns were similar between malignant, borderline and benign tumours, although TGF-beta 1 incidence was reduced in benign tumours. In malignant tumours, the incidence of TGF-beta 1 expression was less than that of either TGF-beta 2 (P = 0.02) or TGF-beta 3 (P = 0.0014), while in both malignant and borderline tumours, TGF-beta 2 and TGF-beta 3 tended to be co-expressed. Aneuploid tumours were more likely than diploid tumours to express multiple rather than single forms of TGF-beta (P = 0.018). The incidence of TGF-beta 1 expression was reduced in PR-moderate/rich (PR > 20 fmol/mg protein) relative to PR-negative/poor tumours (P = 0.048), while TGF-beta 3 expression was increased in ER-moderate/rich (ER > 20 fmol/mg protein) tumours compared to ER-negative/poor tumours (P = 0.0012). Expression of TGF-beta 3, but not TGF-beta 1 or TGF-beta 2, was associated with advanced stage disease (P = 0.014) and, in the malignant group, reduced survival (P = 0.02) with a hazard ratio of 2.6. These data suggest a possible role for TGF-beta 3 in the progression of ovarian cancer.

Disease Progression↗
PubMed1997

The expression of Ki-S1 and BCL-2 and the response to primary tamoxifen therapy in elderly patients with breast cancer.

Ki-S1, a marker of proliferation, and bcl-2, the gene product of which is an antagonist of apoptosis, have been measured in 51 ER-positive primary breast cancers before and during tamoxifen treatment and then related to clinical response. Both markers were detected in the majority of tumours before treatment and, quantitatively, initial expression of Bcl-2 protein, but not Ki-S1, was significantly related to the percentage reduction in tumour volume as assessed by ultrasound. Staining for both markers was lower in post treatment samples than in those taken prior to treatments, but concordant decreases in staining indices were seen in only 11 of the 51 tumours. The results demonstrate, using clinical material, that the response to tamoxifen may involve changes in proliferation and/or susceptibility to cell-death.

Aged↗
PubMed1997

Tamoxifen induced apoptosis in ZR-75 breast cancer xenografts antedates tumour regression.

The ZR-75-1 ER positive breast cancer cell line, xenografted in female nude mice, has been used to determine the effect of tamoxifen on cell proliferation (as measured by mitosis) and cell death (as evidenced by apoptosis and necrosis). After 2 days treatment, there was a significant rise in apoptosis (p < 0.05), whereas a fall in mitosis was not apparent until 7 days (p < 0.05). Furthermore there was an increase in the apoptotic:mitotic ratio on day 7 (p < 0.05). These changes antedated tumour regression, which did not reach not significance until day 14. Tamoxifen did not increase necrosis (which significantly decreased in treated tumours once they had regressed (p < 0.01). In contrast tamoxifen treatment of xenografted MDA-MB-231 ER-negative breast cancer cells produced no significant effects on growth, apoptosis, or mitosis. This study presents clear evidence for tamoxifen inducing apoptosis in ZR-75-1 xenografts (but not MDA-MB-231 tumours). Since changes in apoptosis and mitosis antedate tumour regression, their assessment may provide the potential by which to predict tumour response to tamoxifen therapy.

Animals↗
PubMed1997

Why psychologists should treat alcohol and drug problems.

Because of the prevalence of substance abuse in general clinical populations, it is important for psychologists to have knowledge and skill in this area. Psychologists also have special expertise to offer in the assessment and treatment of alcohol/drug problems. Current evidence indicates that (a) alcohol/drug problems generally obey ordinary behavioral principles and processes, (b) substance abuse frequently occurs within a broader cluster of psychological problems, (c) the treatment approaches most strongly supported by outcome research are fundamentally psychological in nature, (d) cognitive-behavioral principles are of demonstrable value in motivating change in alcohol/drug use, and (e) clinical skills and styles (e.g., empathy) commonly included in the training of psychologists are important determinants of favorable treatment outcomes with substance use disorders. These factors in the context of changing health care indicate that psychologists should play an increasing role in assessing and treating addictive behaviors.

Alcohol-Related Disorders↗
PubMed1997

BRCA1 5382insC mutation in sporadic and familial breast and ovarian carcinoma in Scotland.

A restriction site-generating polymerase chain reaction (RG-PCR) assay was developed to detect the BRCA1 5382insC mutation that has been reported in multiple, apparently unrelated breast/ovarian carcinoma families. The assay has been used to screen tumour DNA from 250 breast cancer patients (aged 19-86 years) and from 80 ovarian cancer patients (aged 25-90 years) in a local population of patients with no known family history. Altogether, 0/80 (0%) ovarian and 1/250 (0.4%) breast tumour DNAs were found to have the 5382insC mutation. The sole positive case was a 26-year-old woman (BC185) with no known family history. One of the reasons for carrying out this analysis was that the 5382insC mutation had previously been shown to segregate with the disease in a very large Scottish 'West Lothian' kindred having breast/ovarian carcinoma. To investigate whether this apparently isolated case and the known family might be related, haplotypes for the markers D17S855, D17S1322, D17S1323 and D17S1327 were analysed. The mutant haplotype in the large kindred was identical to that reported in all other 5382insC mutation families for all markers with the exception of D17S1327. This implies that there has been a recombination event at the telomeric end of common ancestral haplotype in this family. Since the isolated case we identified carries the 'complete' common haplotype, it is unlikely that she is closely related to the West Lothian family.

Adult↗
PubMed1997

The reliability of Form 90: an instrument for assessing alcohol treatment outcome.

OBJECTIVE: Project MATCH is a randomized clinical trial consisting of five outpatient and five aftercare units at nine sites. Of importance in this multisite trial examining the efficacy of client-treatment matching was the cross- and within-site reliability of the structured interview used to assess alcohol treatment outcomes, the Form 90. Evaluation of the reliability of Form 90 is the subject of this article. METHOD: The reliability of Form 90 was evaluated in two test-retest studies. The cross-site reliability study consisted of 70 paired test-retest interviews conducted by different interviewers. Clients for this study were recruited from inpatient, outpatient and college settings. The within-site reliability study had a total of 108 paired test-retest interviews, with 54 of the retests conducted by different interviewers and 54 by the same interviewer. Clients for this study were most often presenting for alcohol treatment at the nine sites and were selected to be representative of the larger Project MATCH sample. RESULTS: Good-to-excellent reliability was found for all key summary measures of alcohol consumption and psychosocial functioning, and most frequently used illicit drugs had moderate reliability. No decay in consistency of self-reported drinking was found at more distal points from dates of test-retest interviews. Application of 68% confidence intervals for primary alcohol consumption measures suggests that trained researchers and clinicians can obtain consistent information regarding client drinking. CONCLUSIONS: Form 90 appears to be a reliable instrument for alcohol treatment assessment research when interviewers have received careful training and supervision in its use.

Adult↗
PubMed1997

Are reconstructed self-reports of drinking reliable?

When follow-up interviews are missed, researchers sometimes try to reconstruct the data that would have been obtained by asking clients to recall the missed interval when they are interviewed at a later point. Are such data reliable? The reliability of remote reconstruction was estimated by asking 57 participants in a clinical trial to recall their drinking for the 12-month follow-up interval when interviewed, on average, 33 weeks later. These reports were obtained after delays averaging 231 days. These reconstructed reports were compared with the same clients' self-reports obtained during the 12-month interview. Reconstructed data were found to be reasonably accurate estimates of clients' reports at the time of original interview on global alcohol use variables including percentage of drinking days and total volume of consumption. No systematic bias was found for over-reporting or under-reporting at the point of reconstruction. However, on some variables (e.g. total drinks consumed), clients on average reported more drinking at the reconstruction period than during the initial interview. Discrepancies between initial and reconstructed reports were found to be unrelated to the length of delay in the second interview or to client characteristics.

Adult↗
PubMed1997

Regulation of aromatase activity within the breast.

Local oestrogen biosynthesis within the breast can be highly variable, in vitro aromatase activity both in breast cancers and mammary adipose tissue displaying over a 40-fold range between the highest and lowest levels. Evidence is presented to show that: (i) transcriptional activity may influence oestrogen biosynthesis within breast cancers in that both aromatase mRNA and STAT nuclear binding are correlated positively to in vitro aromatase activity; (ii) the local presence of cancer may enhance aromatase activity in particulate fractions and primary fibroblast cultures from mammary adipose tissue; (iii) tumour extracts and breast cyst fluids may induce aromatase in cultured fibroblasts, the active principles responsible for these effects being incompletely defined (although the combination of interleukin (IL)-6 and its soluble receptor dramatically enhances aromatase activity, it is unclear whether this particular cytokine system can account for the stimulatory effects of breast extracts and fluids); (iv) the aromatase activities in both breast cancer and adipose tissues are susceptible to classical aromatase inhibitors such as aminoglutethimide and 4-hydroxyandrostenedione (and to newer inhibitors such as CGS16949 and CGS20267 at low nanomolar concentrations) but reduced sensitivity to 4-hydroxyandrostenedione may be observed in certain breast cancers. These findings may have important implications for the development and progression of hormone-dependent cancers within the breast.

Adipose Tissue↗
PubMed1997

Intercessory prayer in the treatment of alcohol abuse and dependence: a pilot investigation.

OBJECTIVE: To conduct a pilot study of the effect of intercessory prayer on patients entering treatment for alcohol abuse or dependence. DESIGN: In addition to standard treatment, 40 patients admitted to a public substance abuse treatment facility for treatment of alcohol problems who consented to participate were randomized to receive or not receive intercessory prayer (double-blind) by outside volunteers. Assessments were conducted at baseline, 3 months, and 6 months. RESULTS: No differences were found between prayer intervention and nonintervention groups on alcohol consumption. Compared with a normative group of patients treated at the same facility participants in the prayer study experienced a delay in drinking reduction. Those who reported at baseline that a family member or friend was already praying for them were found to be drinking significantly more at 6 months than were those who reported being unaware of anyone praying for them. Greater frequency of prayer by the participants themselves was associated with less drinking, but only at months 2 and 3. CONCLUSION: Intercessory prayer did not demonstrate clinical benefit in the treatment of alcohol abuse and dependence under these study conditions. Prayer may be a complex phenomenon with many interacting variables.

Adult↗
PubMed1997

Where to publish? Some considerations among English-language addiction journals.

A search and survey of specialty periodicals in the addiction field identified 35 English-language scientific journals that publish unsolicited research manuscripts. Among these, the typical addiction journal publishes a variety of types of articles in one of many different citation and referencing formats, releases four issues per year to about 1000 subscribers, annually receives more than 100 manuscripts for scientific review, and accepts 53 of them to be published without payment of an author fee. Together these 35 addiction journals publish over 1700 new articles each year. Addiction journals vary widely in acceptance rates, ranging from 26% to 95%, and averaging 53%. For better or worse, these journals offer ample opportunity for the reporting of scientific data in the addiction field.

Humans↗
PubMed1997

Changes in messenger RNA expression of protein kinase A regulatory subunit ialpha in breast cancer patients treated with tamoxifen.

RNA for protein kinase A regulatory subunit Ialpha (RIalpha) has been measured in tumors from 32 breast cancer patients before and during primary treatment with tamoxifen. Values in pretreatment specimens were significantly higher in tumors subsequently responding to treatment as compared with those not (P = 0.004 by Mann-Whitney U test). Furthermore, whereas levels fell with treatment in 16 of the 24 responding tumors, they did not in any of the 8 tamoxifen-resistant tumors (and indeed rose in 6 cases). These results suggest that measurement of RIalpha mRNA may help in identifying endocrine-dependent breast cancers and provide further evidence of the involvement of the protein kinase A system in response and resistance to tamoxifen treatment.

Aged↗
PubMed1996

Effect of Matrigel on the tumorigenicity of human breast and ovarian carcinoma cell lines.

The effect of Matrigel, a solubilised tissue basement membrane extract, has been investigated on the tumorigenicity of 3 breast (MCF-7, T47D and MDA.MB.231) and 5 ovarian [PEO1, PEO1 cDDPr, PEO4, PEO14 and OV(hyg)CAR3] carcinoma cell lines. In the absence of Matrigel, the PEO14 and MDA.MB.231 cell lines produced take rates of 30% and 50%, respectively, while the other cell lines either did not develop or only occasionally developed as tumours. With Matrigel, 100% take rates were achieved for 7 of the 8 cell lines (MCF-7, T47D, MDA.MB.231, PEO1, PEO1 cDDPr, PEO4 and PEO14); in the remaining cell line [OV(hyg)CAR3] 2/6 (33%) tumours grew. Xenografts established with Matrigel could be transferred into recipient animals and grown in the absence of Matrigel, suggesting that Matrigel is necessary only for initial establishment of tumours. Furthermore, cells which had been re-established from a T47D xenograft and then inoculated into mice without Matrigel showed a take rate greater than that of the original cell line but less than that of the xenograft. In conclusion, Matrigel has proven to be extremely useful in establishing a variety of cell lines as xenografts.

Animals↗
PubMed1996

Solid-phase extraction and high-performance liquid chromatographic determination of tamoxifen and its major metabolites in plasma.

Tamoxifen (TAM) is a triphenylethylene anti-oestrogen, commonly used in the treatment of breast cancer. Patients receiving tamoxifen therapy may experience both de novo and acquired resistance. As one of the mechanisms for this may be extensive peripheral bio-transformation of tamoxifen, there has been considerable interest in the pharmacokinetics and metabolism of tamoxifen. A reversed-phase high-performance liquid chromatography separation has been developed to determine the levels of tamoxifen and its major metabolites in human plasma. The method is highly sensitive (2 ng/ml) and selective for tamoxifen, cis-tamoxifen (CIS), 4-hydroxytamoxifen (4-OH) and desmethyltamoxifen (DMT). A micro Bondapak C18 10 microns column (30 cm x 3.9 mm I.D.) was used, with a mobile phase of methanol-1% triethylamine at pH 8 (89:11, v/v). Sample preparation was carried out using a C2 (500 mg sorbent, 3 ml reservoirs) solid phase extraction method, and extraction efficiencies were approximately 60% for TAM and its metabolites. Accuracy and precision, as determined by spiking plasma samples with a mixture of tamoxifen and its metabolites, ranged from 85-110% (+/- 5-10%) at 1 microgram/ml, 101-118% (+/- 8-20%) at 0.1 microgram/ml and 111-168% (+/- 43-63%) at 0.01 microgram/ml. Results from 59 patients show mean values of 54 ng/ml for 4-OH; 190 ng/ml for DMT; 93 ng/ml for TAM and 30 ng/ml for CIS (detected in three patients only). This methodology can be applied routinely to the determination of TAM and its metabolites in plasma from patients undergoing therapy.

Antineoplastic Agents, Hormonal↗
PubMed1996

Elevation of protein kinase A and protein kinase C activities in malignant as compared with normal human breast tissue.

Because of their central role in the transduction of extracellular signals, protein kinases A (PKA) and C (PKC) are critical enzymes in the control of cellular proliferation and differentiation. We have measured the catalytic activity of PKA and PKC, as well as the regulatory subunit expression for PKA, in paired samples of normal and malignant breast tissue from 13 patients with breast cancer. Paired non-parametric (Wilcoxon) analysis revealed significantly higher values for both basal (P = 0.0002) and total (P = 0.0002) PKA catalytic activity in malignant compared with normal breast in all 13 paired tissue samples. Expression of both R1- and RII-PKA regulatory subunits were also higher in malignant tissue from 12 (P = 0.0005) and 9 (P = 0.01) of the 13 pairs, respectively. However, the degree of RI-subunit overexpression in malignant tissue was greater than that of the RII-subunit, as demonstrated by an increase in the RI/RII subunit ratio in 10 of the 13 paired samples (P = 0.017). Total PKC catalytic activity was elevated in 11 of the 13 malignant tissue specimens when compared with corresponding normal breast tissue (P = 0.01). This was accounted for by an increase in Ca(2+)-dependent PKC activity (P = 0.01), there being no significant increase in Ca(2+)-independent PKC activity. These data suggest that the activities of both PKA and PKC signalling pathways are intrinsically higher in malignant compared with normal breast tissue and these may therefore represent targets for interventive treatment of breast cancer.

Adult↗
PubMed1996

Aromatase activity and CYP19 gene expression in breast cancers.

The aromatase enzyme complex is responsible for the conversion of C19 androgens to oestrogens. Aromatase expression in oestrogen-responsive breast cancers may be an important mechanism of autocrine regulation in tumour growth. To evaluate whether aromatase cytochrome P450 (P450arom) transcript levels within breast tumours were correlated to the enzyme activity, a specific competitive reverse transcription-polymerase chain reaction (RT-PCR) was developed. In this reaction, a 32 base-deleted complementary RNA was used as internal standard. In vitro aromatase activity was measured by either the tritium release assay or characterization of oestrogen fractions. Results indicate that there is a positive correlation between P450arom transcript levels and enzyme activity, but the relationship does not reach statistical significance. Therefore, whereas aromatase mRNA quantification may be an option by which to monitor the potential of tumour to synthesize oestrogens, it will not accurately reflect enzyme activity in a minority of tumours. Preliminary evidence was obtained in a tumour with low enzyme activity and a high P450arom transcript level for the presence of an endogenous aromatase inhibitor. This study highlights the necessity to characterize factors involved in the regulation of aromatase activity in such tumours.

Aromatase↗