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Biomedical subjects

W R Miller

Publications and source records attributed to W R Miller.

At least 127 records · Page 7Linked to original sources
PubMed1996

Analysis of cAMP RI alpha mRNA expression in breast cancer: evaluation of quantitative polymerase chain reaction for routine use.

A quantitative polymerase chain reaction (PCR) method for determining concentrations of mRNA for the cyclic AMP (cAMP)-binding protein RI alpha, a regulatory subunit of cAMP-dependent protein kinase, was developed using site-directed mutagenic primers and mix-melt PCR. The PCR product for RI alpha mRNA was modified to include an EcoRV restriction site for use as an internal standard. This mutant utilised the same primers as the target mRNA and differed in sequence by only four bases. As only one of these base changes results in a purine/pyrimidine switch the effective change in labelling with [32P]dCTP was less than 0.5%. Reverse transcription of mRNA was performed and quantitative PCR was carried out using fixed levels of mutant RI alpha vs varying amounts of both normal RI alpha sequence of known concentration and unknown samples. Validation of the technique using rigourous quality control established that reverse transcription, determined by incorporation of labelled nucleotides, gave intra- and interassay variations of 16.2 and 9.3% respectively. Using crossover evaluation of cDNA concentrations with cloned RI alpha sequences as controls intra- and interassay variations of 14.3% and 4-8% respectively were obtained. Using compounded errors, the limits of precision for this technique demonstrate that values that are altered by 50% or more represent a true alteration in mRNA levels between samples tested. This value compares favourably to similar values for radioimmunoassays of between 10% and 30% precision. Analysis of a series of patient samples during routine follow-up of treatment demonstrated clear changes in mRNA levels. Using site-directed mutagenesis to establish a quantitative PCR-based assay for expression of mRNA this study demonstrates the potential usefulness and some limitations of quantitative PCR for applications within a clinical biochemistry laboratory. However, based on compounded error, values that vary by less than 50% within assays, and by less than 70% in separate assays could not be clearly separated. Assessment of paired patient samples has demonstrated clear changes in mRNA for the target protein RI alpha. With the use of normal quality control procedures this study has established that the degree of reproducibility of this quantitative PCR technique would allow assessment of mRNA levels for markers of interest in clinical samples in a routine laboratory context.

Base Sequence↗
PubMed1996

Changes in expression of transforming growth factor beta mRNA isoforms in patients undergoing tamoxifen therapy.

Tumour was obtained from 37 patients with oestrogen receptor-positive breast cancer, before and during treatment with tamoxifen, and examined qualitatively and semi-qualitatively for mRNA of the three mammalian TGF-beta isoforms. Levels of TGF-beta isoforms were then correlated with tumour response to tamoxifen, as assessed by monthly ultrasound. A high incidence of expression by each isoform was found in tumour material taken both before and during treatment. Semiquantitative assessment of mRNA showed that in the majority of tumours, expression of TGF-beta s did not change markedly with treatment, i.e. beyond that which might have been caused by method reproducibility and tumour heterogeneity (variations of < 100% between pre- and post-treatment samples). In those displaying significant variation with treatment, expression of TGF-beta 1 and -beta 3 increased or decreased in equal numbers, whereas TGF-beta 2 expression tended to increase with treatment. Subdividing tumours by clinical response revealed no significant association between changes in expression of TGF-beta 1 and TGF-beta 3. There was, however, a significant correlation between changes in expression of TGF-beta 2 and response (P = 0.018). Thus, of 15 responding tumours displaying substantial changes, 11 showed an increase in TGF-beta 2 expression with treatment, whereas none of the non-responding tumours were associated with increased expression. While not providing evidence for a generalised increase in TGF-beta expression with tamoxifen treatment, the present study suggests that response to tamoxifen therapy may be associated with an increase in expression of specific TGF-beta isoforms in some, but not all, tumours.

Aged↗
PubMed1996

Expression of the extracellular matrix protein tenascin in malignant and benign ovarian tumours.

The extracellular matrix protein tenascin (TN) is overexpressed in a number of solid tumours. Thi however, is the first study to examine TN expression in ovarian tumours. TN protein was examined in froze sections of 50 human ovarian tumours by immunohistochemistry. Malignant and borderline tumours showed significantly greater incidence and intensity of stromal staining than benign tumours (P < 0.0001 and P = 0.038 respectively). Seven omental metastases were also examined and showed a strikingly similar protein distribution to their primary tumour counterparts. The expression pattern of different RNA isoforms, created by alternative splicing of the primary transcript, was identified using reverse transcription-polymerase chain reactions (RT-PCR). The smallest TN RNA splice variant (284 bp) was found in all tumours examined, while the appearance of larger molecular weight transcripts (approximately 490 and 556 bp), as major forms, was predominantly limited to malignant tumours, with 9/12 malignant tumours showing this pattern compared with 1/6 benign tumours. These data suggest that malignant ovarian tumours have increased expression of TN compared with benign tumours and this may be associated with induction of specific isoforms.

Female↗
PubMed1996

The prognostic value of epidermal growth factor receptor mRNA expression in primary ovarian cancer.

The expression of mRNA for the epidermal growth factor (EGF) receptor, EGF and transforming growth factor alpha (TGF-alpha) was determined in 76 malignant, six borderline and 15 benign primary ovarian tumours using the reverse transcriptase-polymerase chain reaction and related to clinical and pathological parameters. Of the malignant tumours, 70% (53/76) expressed EGF receptor mRNA, 31% (23/75) expressed EGF mRNA and 35% (26/75) expressed TGF-alpha mRNA. For the borderline tumours, four of six (67%) expressed EGF receptor mRNA, 1/6 (17%) expressed TGF-alpha mRNA and none expressed EGF mRNA. Finally, 33% (5/15) of the benign tumours expressed EGF receptor mRNA, whereas 40% (6/15) expressed EGF mRNA and 7% (1/15) expressed TGF-alpha mRNA. The presence of the EGF receptor in malignant tumours was associated with that of TGF-alpha (P = 0.0015) but not with EGF (P = 1.00), whereas there was no relationship between the presence of EGF and TGF-alpha (P = 1.00). EGF receptor mRNA expression was significantly and positively associated with serous histology (P = 0.006) but not with stage or grade. Neither EGF nor TGF-alpha showed any link with histological subtype or stage. The survival of patients with malignant tumours possessing EGF receptor mRNA was significantly reduced compared with that of patients whose tumours were negative (P = 0.030 for all malignant tumours; P = 0.007 for malignant epithelial tumours only). In contrast, neither the expression of TGF-alpha nor EGF was related to survival. These data suggest that the presence of EGF receptor mRNA is associated with poor prognosis in primary ovarian cancer.

Base Sequence↗
PubMed1996

Prospective evaluation of prognostic factors in operable breast cancer.

In 215 patients with operable breast cancer (T1-T3, N0-1, M0) and no other or previous cancer, presenting to a single breast unit, sufficient tumour was available for the prospective determination of four putative biochemical markers of prognosis: oestrogen receptor (ER) activity, cathepsin D (cath D), epidermal growth factor receptor (EGFR) activity and cyclic AMP-binding proteins (c-AMP-b). There were significant inter-relationships between ER and EGFR (r = -0.26), c-AMP-b and cath D (r = +0.32) and ER and c-AMP-b (r = +0.14). After follow-up (median 36.2 months), a total of 55 recurrences (18 locoregional only) and 35 deaths were recorded. By univariate analysis, up to 10 of 18 biochemical, clinical and histopathological variables of potential prognostic value were significantly related to disease-free interval or death, but by multivariate analysis only oestrogen receptor concentration and node status contributed significantly to risk of both distant recurrence/death; in addition, tumour size made a small contribution to the risk for a distant recurrence only. Only two parameters, tumour grade and ER concentration, were significantly related to risk of locoregional recurrence by univariate analysis, but by multivariate analysis, only tumour grade was important. It is concluded that tumour ER concentration, axillary nodal status and tumour grade remain as the most important prognostic factors in the early years after presentation of operable breast cancer, with a minor influence of tumour size. At this time, the prognostic significance of quantitative measurements of ER concentration, carefully controlled for the quality of both assay and tumour specimen, is probably greater than is generally appreciated. We have yet to identify other factors, which add significantly to the short-term prognostic value of these key features.

Age Factors↗
PubMed1996

How to have a high success rate in treatment: advice for evaluators of alcoholism programs.

Two seasoned alcohol treatment researchers offer tongue-in-cheek advice to novice program evaluators faced with increasing pressure to show high success rates. Based on published examples, they advise: (1) choose only good prognosis cases to evaluate; (2) keep follow-up periods as short as possible; (3) avoid control and comparison groups; (4) choose measures carefully; (5) focus only on alcohol outcomes; (6) use liberal definitions of success; (7) rely solely upon self-report and (8) always declare victory regardless of findings.

Alcoholism↗
PubMed1996

Pharmacokinetics, metabolism and tumour disposition of 8-chloroadenosine 3',5'-monophosphate in breast cancer patients and xenograft bearing mice.

BACKGROUND: 8-Chloroadenosine 3',5'-monophosphate (8-Cl-cAMP) is undergoing phase I clinical trials as an anticancer drug. However, there is debate as to whether it is a prodrug for its 8-Cl-adenosine metabolite. DESIGN: Pharmacokinetics, metabolism and tumour disposition studies have been performed in 7 breast cancer patients receiving continuous infusion (28 day) 8-Cl-cAMP (0.54 or 1.08 mg/kg/day) and tumour biopsies were obtained before and on the last day of infusion. Parallel studies were performed in nude mice bearing the HT29 human colon cancer xenograft after continuous infusion (7 day) of active drug doses (50 or 100 mg/kg/day). RESULTS: Steady state plasma levels (Css) of 8-Cl-cAMP in patients ranged from 0.15-0.72 microM but 8-Cl-adenosine was not detected in plasma. In contrast, 8-Cl-cAMP was not detectable in 3 tumour biopsies but 8-Cl-adenosine was present in 2 samples at high concentrations (1.33 and 2.02 microM). In mice, Css of 8-Cl-cAMP ranged from 3.2-4.6 microM and 8-Cl adenosine was present in plasma only at the higher dose (100 mg/kg/day, peak concentration of 2.3 microM). In the HT29 xenograft, 8-Cl-cAMP levels were considerably lower than in plasma (0.37-1.22 microM) while 8-Cl-adenosine was present at 5.3-21.0 microM and 8-Cl-AMP was found at 11.3-35.7 microM. CONCLUSIONS: The fate of 8-Cl-cAMP in human tumours is characterised by extensive metabolism to products which are not generally observed in plasma. These data raise the possibility that 8-Cl-cAMP is a prodrug for a product of its metabolism in human tumours.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1996

Alcohol, drug use and consequences among Hispanics seeking treatment for alcohol-related problems.

OBJECTIVE: Ethnic differences in alcohol consumption patterns are often reported in general population surveys, but less is known about variation among ethnic groups presenting for treatment. METHOD: Within a larger clinical trial, patterns of drinking, drug use and related problems were compared for Hispanic (n = 102) and non-Hispanic white (n = 104) male (n = 154) and female (n = 52) clients presenting at a public clinic for outpatient treatment of alcohol problems. RESULTS: Relatively few reliable ethnic differences were observed in alcohol /drug use patterns. Non-Hispanic white men reported significantly more pretreatment tobacco use than did Hispanic men (84.7% vs 61.3% of past 90 days). Hispanic women reported significantly fewer legal problems (28.6% vs 83.9%), symptoms of dependence and negative consequences of drinking relative to non-Hispanic white women. Measures of acculturation and acculturative stress failed to differentiate drinking patterns among Hispanic clients. CONCLUSIONS: Within a treatment-seeking sample, Hispanics and non-Hispanics may be more similar with regard to drinking practices than is the case in the general population. High consumption, adverse consequences and dependence symptoms were characteristic of men presenting for alcohol treatment regardless of ethnic identification. In contrast, Hispanic treatment-seeking women had the lowest consumption, adverse consequences and dependence symptoms of all the groups described, and they reported significantly fewer alcohol-related problems and symptoms than did non-Hispanic women.

Acculturation↗
PubMed1996

Meta-analysis of the literature on Alcoholics Anonymous: sample and study characteristics moderate findings.

OBJECTIVE: Reviews of research on Alcoholics Anonymous (AA) have speculated how findings may differ when grouped by client and study characteristics. A meta-analytic review by Emrick et al. in 1993 provided empirical support for this concern but did not explore its implications. This review divided results of AA affiliation and outcome research by sample origin and global rating of study quality. The review also examined the statistical power of studies on AA. METHOD: Meta-analytic procedures were used to summarize the findings of 74 studies that examined AA affiliation and outcome. Results were divided by whether samples were drawn from outpatient or inpatient settings and a global rating of study quality that jointly considered use of subject selection and assignment, reliability of measurement and corroboration of self-report. Efficacy of dividing study results was examined by changes in magnitude of correlations and unexplained variance. RESULTS: AA participation and drinking outcomes were more strongly related in outpatient samples, and better designed studies were more likely to report positive psychosocial outcomes related to AA attendance. In general, AA studies lacked sufficient statistical power to detect relationships of interest. CONCLUSIONS: AA experiences and outcomes are heterogeneous, and it makes little sense to seek omnibus profiles of AA affiliates or outcomes. Well-designed studies with large outpatient samples may afford the best opportunity to detect predictors and effects of AA involvement.

Alcoholics Anonymous↗
PubMed1996

What is a relapse? Fifty ways to leave the wagon.

Binary thinking has often guided research and practice in the addiction field. For example, emphasis has been given to identifying whether an individual is "alcoholic" or not, and the dichotomous judgement that a client is either drinking or abstinent has been used to judge treatment effectiveness. Research on the nature of alcohol problems, however, indicates that they lie along several modestly interrelated continuous dimensions of severity, rather than occurring as a single syndrome qualitatively distinct from normality. Similarly, changes in addictive behaviors in general, and treatment outcomes in particular, are complex phenomena not readily captured by dichotomous classification. The term "relapse" is itself seriously problematic in various ways, and its definition elusive. It represents a somewhat arbitrary binary judgement imposed on the flow of behavior, and carries negative evaluative overtones. A potentially detrimental abstinence violation effect is implicit in the very use of the term "relapse", which thereby may become a self-fulfilling prophecy. Further, it implicitly pathologizes what is in fact a rather common event in the course of behavior change, and embodies an unrealistic and inaccurate conception of how successful change occurs over time. For these reasons, it may be useful in research and clinical practice to abandon the notion of "relapse" and focus instead on terminology that better describes the normal resolution process for addictive behaviors.

Alcoholism↗
PubMed1996

What predicts relapse? Prospective testing of antecedent models.

Predictors of relapse to drinking were examined in a clinical sample of 122 individuals seeking outpatient treatment for alcohol problems. Drinking status and a variety of predictor variables were measured every two months for one year following presentation for treatment. In addition to pretreatment characteristics, potential antecedents of relapse were assessed at each point within five domains: (1) the occurrence of negative life events; (2) cognitive appraisal variables including self-efficacy, alcohol expectancies, and motivation for change; (3) client coping resources; (4) craving experiences; and (5) affective/mood status. Although the occurrence of adverse life events did not predict 6-month relapse, all other domains singly accounted for significant variance in drinking outcomes. Proximal antecedents (from the prior 2-month interval) significantly and substantially improved predictive power over that achieved from pretreatment characteristics alone. When analyzed jointly, these predictors accounted for a majority of variance in 6-month relapse status. A prospective test supported Marlatt's developmental model of relapse, pointing to two client factors as optimally predictive of resumed drinking: lack of coping skills and belief in the disease model of alcoholism.

Adult↗
PubMed1996

Looking forward and back to relapse: implications for research and practice.

In this commentary, the three principal investigators of the Relapse Replication and Extension Project (RREP) reflect on clinical and research implications of study findings from the three collaborating sites. A primary purpose of RREP was to study the reliability and validity of a taxonomy of relapse antecedents originally proposed by Marlatt two decades ago. Under the best of research conditions, with extensive training and practice, it was difficult to achieve reliability of coding with the original three-level system, although with only two levels of classification more reasonable albeit variable reliability was found. Modifications may improve the taxonomy's reliability, but RREP data indicate that a more appropriate strategy is to measure possible antecedents of relapse by continuous scales such as those provided by Annis, Heather and Litman. There is reasonably consistent evidence for two common antecedents of relapse: negative emotional states, and positive emotional states in a social context. Antecedents of relapse show only modest consistency within individuals from one occasion to the next. The causes to which clients attribute relapses may exert a significant effect on future drinking episodes. Stable and internal attributions, such as are commonly associated with a dispositional disease model, may serve to perpetuate relapse. From the RREP studies, the availability of coping skills appears to be a potent protective factor, and ineffective coping a consistent predictor of relapse. Implications for clinical research and practice are considered.

Adaptation, Psychological↗
PubMed1996

Cyclic adenosine 3',5'-monophosphate-binding proteins in human ovarian cancer: correlations with clinicopathological features.

The regulatory subunits of protein kinase A, or cyclic AMP-binding proteins, were measured in a series of 107 human ovarian tumors (89 malignant, 7 borderline, and 11 benign tumors) and related to tumor clinicopathological features and patient survival. Total cyclic AMP-binding protein levels were not significantly different between malignant tumors and either borderline or benign tumors. However, serous tumors showed significantly higher levels of total cyclic AMP-binding proteins than other malignant tumors (P = 0.007). Poorly differentiated tumors also possessed significantly higher levels of binding proteins as compared with well/moderately differentiated tumors (P < 0.01). Retrospective analysis of follow-up data also revealed a significant trend for patients with high tumor cyclic AMP-binding proteins to have poorer survival (P = 0.03). Individual binding proteins were identified by photoaffinity labeling, and the RI (Mr 48,000) protein was expressed as a percentage of total cyclic AMP-binding proteins detected. The percentage of the RI protein was not significantly different among malignant, borderline, or benign pathologies and was not associated with tumor stage, differentiation, or debulk status. The percentage of RI was significantly increased in serous tumors compared to other common epithelial malignancies (P = 0.01). In malignant tumors there was a significant positive correlation between the percentage of the RI protein and total cyclic AMP-binding proteins (P = 0.01). These data indicate that high tumor levels of cyclic AMP-binding proteins are associated with serous histology, poor differentiation, and poor patient survival.

Carrier Proteins↗
PubMed1995

c-erbB growth-factor-receptor proteins in ovarian tumours.

Immunohistochemical expression of EGF-R, c-erbB-2 and c-erbB-3, members of the type-1 family of receptor tyrosine kinases, were investigated in 67 primary ovarian-tumour samples (46 malignant, 8 borderline and 13 benign), and related to tumour clinicopathological features. The incidence of all 3 receptor proteins was highest in overtly malignant tumours. No significant correlations were observed between either EGF-R or c-erbB-3 and clinical parameters such as tumour stage, differentiation or extent of debulking surgery, but c-erbB-2 was significantly associated with several indicators of prognosis, including early stage and good/moderate differentiation in optimally debulked tumours. Multiple expression of c-erbB receptor proteins was also significantly higher in malignant tumours compared with borderline and benign tumours. Early-stage tumours were also more likely to express multiple c-erbB-receptor proteins than were late-stage tumours. Co-expression of EGF-R with c-erbB-2, and c-erbB-2 with c-erbB-3 was significantly greater in malignant tumours than in borderline or benign tumours, and within the malignant tumour group, positive associations were observed between EGF-R and c-erbB-3, also between c-erbB-2 and c-erbB-3. Because of the evidence of increased expression of individual c-erbB proteins as well as multiple expression of this family of growth-factor receptors in malignant ovarian tumours, we hypothesize that stimulation by the appropriate ligands may confer a selective advantage to cells expressing more than one receptor. Increased expression of c-erbB growth-factor receptors in malignancy may mediate increased propensity for tumour development.

Adult↗
PubMed1995

Prevalence estimates of alcohol problems in a Veterans Administration outpatient population: AUDIT vs. MAST.

Prior reports have indicated that the prevalence of alcohol-related problems in VA patients is significantly higher than that found in the general population. Prevalence rates, however, are likely to be affected by the screening instrument employed. A sample of 722 VA outpatients awaiting general medical and urgent care treatment was asked to complete two screening questionnaires: the World Health Organization's AUDIT and the brief MAST. Of 508 completed AUDITs, 55 (11%) scored above the cut-offs of 11 for harmful consumption, and 85 (17%) above the more liberal cut-off score of 8; whereas of 501 completed MASTs, 104 (21%) scored above the cut-off. Differences in identification rates are discussed.

Adolescent↗