Biomedical subjects

Matthew S Mayo

Publications and source records attributed to Matthew S Mayo.

46 records · Page 3Linked to original sources

PubMed2002

African American smokers interested and eligible for a smoking cessation clinical trial: predictors of not returning for randomization.

PURPOSE: Recruitment is often the rate-limiting step in conducting clinical trials among ethnic minorities. Little is known about participants who consent and enroll into a trial, but do not return for randomization. Why participants fail to return for randomization is largely unknown. METHODS: We compared 287 enrolled African American smokers who did not return for randomization, to the 500 who returned and were randomized to participate in a clinical trial for smoking cessation in African Americans. Analyses were conducted to identify variables associated with not returning for randomization. RESULTS: Univariate comparisons found the nonrandomized group to be significantly different from those randomized. Logistic regression showed younger age, less readiness to quit, having been proactively recruited, lacking a regular source of health care, believing that they will be smoking in 6 months, less church attendance, and a lower literacy level to be jointly related with not returning for randomization. CONCLUSIONS: African American participants who did not return for randomization into a clinical trial were different from those who did. Better understanding of these factors may allow researchers to target recruitment efforts resulting in enhanced accrual in clinical trials and increased efficiency.

Adult↗

PubMed2002

Factors associated with success of the extreme drug resistance assay in primary breast cancer specimens.

The extreme drug resistance (EDR) assay has not been widely studied in the setting of non-metastatic breast cancer. We evaluated the feasibility of performing the assay in 144 primary breast tumor specimens from two institutions by determining the rate of successful tumor culture for assays, number of drugs evaluated per assay, and time from tumor biopsy to receipt of results. We also sought to determine factors that are associated with assay success. An exploratory analysis was performed to detect possible associations between estrogen receptor (ER), progesterone receptor (PR) and HER2/NEU over-expression and extreme drug resistance demonstrated by the assay for specific chemotherapeutic agents. Of 144 tumor specimens submitted, tumor was successfully cultured for assay in 101(70%) of cases. A median of five drugs was evaluated per assay (range 2-9). Results were obtained in a median of 8 days (range 2-29). Young age, high tumor grade, PR negativity, and higher tumor submission weight were predictive for a successful assay. EDR was observed in 7-15% of tumors to doxorubicin, cyclophosphamide, 5-fluorouracil (5FU) and mitoxantrone, but EDR to paclitaxel was observed in 35%. Extreme drug resistance to 5-FU was associated with negative ER and PR status. There was a trend toward association between EDR to paclitaxel and HER2/NEU over-expression. The EDR assay may be successfully performed in the majority of tumors, and assay results are available in a timely fashion such that adjuvant treatment drug selection could be guided by results. These results may be helpful for designing possible future trials that evaluate the assay's role in adjuvant chemotherapy selection.

Age Factors↗

PubMed2002

Patients' views on smoking cessation and tobacco harm reduction during drug treatment.

Efforts to help smokers in drug treatment quit smoking have met with little success. To explore barriers to quitting and interest in tobacco harm reduction we conducted focus groups and interviews among 78 patients from five Methadone Maintenance Treatment (MMT) sites. Measures included a written survey and open-ended questions on (a) motivation for quitting, (b) what quit methods worked and what didn't work, and (c) interest in smoking reduction and nicotine maintenance as an alternative to complete cessation. Discussions were audiotaped, transcribed, and coded using computer-based qualitative software; our interobserver reliability was 83%. Successful quitters used in general a combination of quit methods such as prayer, nicotine gum, keeping busy, quitting 'one day at a time,' nicotine patches, deep breathing, and avoidance of triggers. Nicotine craving, rather than withdrawal, was cited as the biggest challenge to staying quit. Some current smokers feared quitting smoking would divert them from their goal of quitting illicit drug use or tapering off MMT. Current smokers were interested in smoking reduction as an alternative to quitting; however, those who had tried but failed to reduce smoking preferred complete cessation. Nicotine maintenance was favored by only a few participants with major health problems who didn't hold out hope for quitting. Findings suggest combination pharmacotherapy could help patients control withdrawal and acute episodes of craving. Patients have a number of skills from coping with illicit drug dependence that are useful in combating nicotine dependence. Behavioral methods and short-term pharmacotherapy to help patients reduce tobacco exposure should be explored.

Adult↗

PubMed2002

Participation of African Americans in a smoking cessation trial: a quantitative and qualitative study.

African Americans (AAs) have been considered a hard to reach research population. In a clinical trial of bupropion for smoking cessation, failure to return for randomization was concerning during the initial phase of recruitment. There were three study goals: to review the research on clinical trial participation barriers, to use quantitative analyses to identify differences between randomized (n = 66) and non-randomized (n = 54) participants, and to use focus groups and interviews (2 groups and 2 interviews, 17 participants) to elicit participation barriers and suggestions for participation enhancement. Randomized participants were older (44.1 vs. 37.6; p = 0.0019), predominately female (81.8% vs. 63.0%; p = 0.0201), more likely to have some college (33.3% vs. 16.7%; p = 0.0380), and less likely to be employed full time (32.4% vs. 53.7%; p = 0.0347). Randomized participants reported higher motivation to quit smoking (8.3 vs. 7.3; p = 0.0083) and higher confidence to quit (8.2 vs. 7.3; p = 0.0357). A logistic regression model specified age, gender, and motivation to quit, as predictors of randomization. Focus groups identified transportation, lack of readiness to quit, inadequate reminders, and employment conflicts as barriers to participation. Knowledge of differences between those who return for enrollment and those who do not may be used to increase AA enrollment in clinical trials.

Adult↗

PubMed2002

A phase II breast cancer chemoprevention trial of oral alpha-difluoromethylornithine: breast tissue, imaging, and serum and urine biomarkers.

PURPOSE: A double-blind randomized Phase II chemoprevention trial of alpha-difluoromethylornithine (DFMO) was conducted in a group of women at high risk for development of breast cancer. DFMO is an irreversible inhibitor of ornithine decarboxylase, the limiting enzyme of polyamine synthesis that is often up-regulated in breast cancer. EXPERIMENTAL DESIGN: Study entrants were required to have random periareolar fine-needle aspiration cytology prior to entry that exhibited hyperplasia or hyperplasia with atypia, as well as a mammogram and clinical breast exam judged as not suspicious for breast cancer and no clinical hearing loss. Subjects were randomized to 6 months of oral DFMO (0.5 g/m(2)/day) or placebo, followed by repeat fine-needle aspiration and biomarker assessment. The main study end point was an improvement in cytologic pattern. RESULTS: Of 119 subjects entered, 96% completed the study and were evaluable for the main study end point. A modest reduction (28%) in average total urine polyamines was obtained in the DFMO group, but there was no reduction in the spermidine:spermine ratio. There was no difference in cytologic improvement between DFMO and placebo. Likewise, there was no difference between DFMO and placebo for the secondary end points of breast molecular marker changes (immunocytochemical expression of proliferating cell nuclear antigen, p53, and epidermal growth factor receptor), mammographic breast density, serum insulin-like growth factor I: insulin-like growth factor binding protein 3 ratio, adverse events, quality of life indices, or subsequent cancer development. CONCLUSIONS: DFMO at a dose level of 0.5 g/m(2)/day administered for 6 months does not modulate breast risk biomarkers tested in this study.

Administration, Oral↗

PubMedDate not supplied

Sustained-release bupropion for smoking cessation in African Americans: a randomized controlled trial.

CONTEXT: African Americans disproportionately experience greater smoking attributable morbidity and mortality. Few clinical trials for smoking cessation in African Americans have been conducted, despite a different profile of both smoking and quitting patterns. OBJECTIVE: To compare a sustained-release form of bupropion hydrochloride (bupropion SR) with placebo for smoking cessation among African Americans. DESIGN, SETTING, AND PARTICIPANTS: Randomized, double-blind, placebo-controlled trial conducted from February 11, 1999, to December 8, 2000, of 600 African American adults treated at a community-based health care center. Volunteers, who smoked 10 or more cigarettes per day were recruited by targeted media and health care professionals. INTERVENTION: Participants were randomly assigned to receive 150 mg of bupropion SR (n = 300) or placebo (n = 300) twice daily for 7 weeks. Brief motivational counseling was provided in-person at baseline, quit day, weeks 1 and 3, end of treatment (week 6), and by telephone at day 3 and weeks 5 and 7. MAIN OUTCOME MEASURES: Biochemically confirmed 7-day point prevalence abstinence at weeks 6 and 26 following quit day. RESULTS: Using intention-to-treat procedures, confirmed abstinence rates at the end of 7 weeks of treatment were 36.0% in the bupropion SR group and 19.0% in the placebo group (17.0 percentage point difference; 95% confidence interval, 9.7-24.4; P<.001). At 26 weeks the quit rates were 21.0% in the treatment and 13.7% in the placebo groups (7.3 percentage point difference; 95% confidence interval, 1.0-13.7; P =.02). Those taking bupropion SR experienced a greater mean reduction in depression symptoms at week 6 (2.96 [9.45] vs 1.13 [8.84]) than those taking placebo, and after controlling for continuous abstinence, those taking bupropion SR also gained less weight than those taking placebo. CONCLUSIONS: Bupropion SR was effective for smoking cessation among African Americans and may be useful in reducing the health disparities associated with smoking.

Adult↗

PubMedDate not supplied

WISP-2 gene in human breast cancer: estrogen and progesterone inducible expression and regulation of tumor cell proliferation.

WISP-2 mRNA and protein was overexpressed in preneoplastic and cancerous cells of human breast. Statistical analyses show a significant association between WISP-2 expression and estrogen receptor (ER) positivity. In normal breast, the expression was virtually undetected. The studies showed that WISP-2 is an estrogen-induced early response gene in MCF-7 cells and the expression was continuously increased to reach a maximum level at 24 h. The estrogen effect was inhibited by a pure antiestrogen (ICI 182,780). Human mammary epithelial cells, in which WISP-2 expression was undetected or minimally detected, responded to 17beta-estradiol by upregulating the WISP-2 gene after transfection with ER-alpha, providing further evidences that WISP-2 expression is mediated through ER-alpha. Overexpression of WISP-2 mRNA by estrogen may be accomplished by both transcriptional activation and stabilization. MCF-7 cells exposed to progesterone had a rapid but transient increase in WISP-2 expression, and PR antagonist RU38486 blocked this mRNA induction. In combination with estradiol, progesterone acted as an antagonist inhibiting the expression of WISP-2 mRNA. Moreover, disruption of WISP-2 signaling in MCF-7 cells by use of antisense oligomers caused a significant reduction in tumor cell proliferation. The results are consistent with the conclusion that WISP-2 expression is a requirement for breast tumor cells proliferation.

Adult↗

PubMedDate not supplied

Cancer cluster investigations: use of a hybrid approach in a rural county.

A rural community expressed concern about a perceived excess of kidney and pancreatic cancer coupled with contamination of drinking water with atrazine, benzene, ethylene dibromide, and nitrate. Incidence and mortality for these two cancers were compared to what might be expected. A literature review was conducted for risk factors for kidney and pancreatic cancer as well as for the effects of the above 4 chemicals on these 2 cancers. Interviews with cases or surrogates ascertained chemical and risk factor exposures for these 2 cancers. Chemical exposures found in the public drinking water supply were evaluated as to their carcinogenicity. Hospital cases were compared to cases in the cancer registry. No statistically significant increases in kidney and pancreatic cancer incidence or mortality were found. The major risk factor found in the literature for these 2 cancers was smoking. Most of the cases were smokers and the chemicals found in the drinking water were not found to pose a risk for these 2 cancers. This approach provided considerable information, suggested prevention options and additional research, and is recommended for responding to cancer cluster concerns originating in the community (reactive approach). A proactive approach to cancer cluster surveillance and research was also used and is recommended for state or large local health departments.

Cluster Analysis↗

PubMedDate not supplied

Brain cancer in a residential area bordering on an oil refinery.

Both in response to community concerns about brain cancer related to an oil refinery and in order to more fully understand the etiology of primary site brain cancer (glioma), a highly focused cancer cluster investigation was conducted. The components included: (1) a literature review of occupational exposures in the petroleum refining and petrochemical industries, (2) comparisons between observed and expected cases, (3) comparisons between mean age at diagnosis and median survival time and (4) interviews concerning exposures of cases. Evidence from the literature review revealed little, if any, effect of petroleum refinery or petrochemical exposure on the risk for brain cancer. There was no statistically significant increase in the number of brain cancer cases in the community (observed = 12, expected = 9.46, standardized mortality ratio = 1.27). There was no statistically significant decrease in mean age at diagnosis or median survival time among those most exposed. Reports of exposure from the case interviews were highest for eating processed meats (98.5%), dental X-rays (96.6%), dog ownership (91.2%) and swimming (80.3%). There were no major occupational exposures identified. It seems unlikely that petrochemicals are involved in any significant way in the etiology of most brain cancers (gliomas). A follow-up case-control study should focus primarily on those risk factors mentioned frequently by the cases.

Brain Neoplasms↗

PubMedDate not supplied

Baseline characteristics and recruitment strategies in a randomized clinical trial of African-American light smokers.

PURPOSE: This study describes the design, recruitment, and baseline data of the first smoking-cessation clinical trial for African-American light smokers, Kick It at Swope II (KIS-II). DESIGN: KIS-II was a randomized trial testing the efficacy of nicotine gum (vs. placebo gum) in combination with counseling (motivational interviewing or health education). SETTING: This study was conducted at an urban community-based clinic serving predominantly lower-income African-Americans. SUBJECTS: African-Americans who smoked 1 to 10 cigarettes per day were eligible. Of 1933 individuals screened, 1012 (52%) were eligible and 755 (75%) were enrolled in the study. MEASURES: Baseline assessment included smoking history and psychometric measures. ANALYSIS: The majority of participants were women (67%) with a mean age of 45.1 years (SD = 10.7). Participants smoked on average 7.6 cigarettes (SD = 3.21) per day, had a mean exhaled carbon monoxide level of 13.9 ppm (SD = 8.9) and a mean serum cotinine level of 244.2 ng/mL (SD = 154.4), and reported high levels of motivation and confidence to quit smoking. CONCLUSION: African-American light smokers were motivated to stop smoking and to enroll in a smoking-cessation program. Characteristics of our sample suggest African-American light smokers are an appropriate group for inclusion in smoking-cessation interventions.

Adult↗