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Matthew S Mayo

Publications and source records attributed to Matthew S Mayo.

At least 37 records · Page 2Linked to original sources
PubMed2005

Self-efficacy and motivation to quit during participation in a smoking cessation program.

The associations between failure to quit and posttreatment self-efficacy and motivation were examined among 600 African American smokers enrolled in a randomized trial testing the efficacy of bupropion for smoking cessation. Participants also received brief motivational counseling and were followed for 6 months. Baseline levels of self-efficacy and motivation for all participants were high (8.2 and 8.5 on a 10-point scale, respectively). Longitudinal analyses indicated that smokers who failed to quit were less likely than quitters to report high self-efficacy and motivation from posttreatment to follow-up. However, examination of mean self-efficacy and motivation scores at posttreatment and follow-up revealed that smokers continued to sustain high self-efficacy and motivation. Mean self-efficacy and motivation scores differed by less than 1 point from baseline levels, even though the majority of participants failed to quit smoking. Results suggest that unsuccessful participation in a smoking cessation program does not meaningfully reduce smokers' self-efficacy and motivation to quit.

Adult↗
PubMed2005

Factors associated with BMI, weight perceptions and trying to lose weight in African-American smokers.

This study examined sociodemographic, behavioral and psychosocial factors associated with BMI, weight perceptions and trying to lose weight among African-American smokers (N=600, M=44.2 years, 70% female). Sixty-eight percent of the sample were overweight or obese (sample BMI M=28.0, SD=6.7). Three separate, simultaneous multivariable regression models were used to determine which factors were associated with BMI, weight perceptions and trying to lose weight. Poorer health, female gender and high-school education or higher were significantly associated with higher BMIs (p<0.05). Being female (OR=5.8, 95% CI=3.6-9.3) and having a higher BMI (OR=0.6, 95% CI=0.5-0.6) was associated with perception of overweight and smoking more cigarettes per day (OR=1.0, 95% CI=1.0-1.1), and perceiving oneself as overweight (OR=14.1, 95% CI=8.2-24.2) was associated with trying to lose weight. Participants somewhat underestimated their BMI in their weight perceptions. Those who perceived themselves as overweight were more likely to be trying to lose weight; therefore, increasing participant awareness of actual BMI status may lead to improved weight-control efforts in African-American smokers. Several expected associations with outcomes were not found, suggesting that BMI and weight constructs are not well-understood in this population.

Adult↗
PubMed2004

Breast cancer chemoprevention phase I evaluation of biomarker modulation by arzoxifene, a third generation selective estrogen receptor modulator.

PURPOSE: Arzoxifene, a new selective estrogen receptor modulator with strong breast antiestrogen activity and absence of uterine agonist activity, was explored as a potential chemoprevention agent. We performed a multi-institutional evaluation of arzoxifene in women with newly diagnosed ductal carcinoma in situ or T1/T2 invasive cancer. EXPERIMENTAL DESIGN: In a Phase IA trial, 50 pre- or postmenopausal women were randomized to 10, 20, or 50 mg of arzoxifene daily in the interval between biopsy and re-excision or were enrolled as no-treatment controls. In a Phase IB trial, 76 postmenopausal women were randomized to 20 mg of arzoxifene versus matched placebo. Serum specimens collected at entry and at re-excision were assayed for various hormones and growth factors. Tissue from biopsies (estrogen receptor + and/or progesterone receptor +) and re-excision specimens was evaluated immunohistochemically for proliferation (Ki-67 by MIB-1 and proliferating cell nuclear antigen) and other biomarkers. RESULTS: In both trials, increases in serum sex hormone binding globulin were noted, as were decreases in insulin-like growth factor (IGF)-I and the IGF-I:IGF binding protein-3 ratio (P < 0.007 versus control/placebo). For 45 evaluable women in Phase IA, decreases in proliferation indices were more prevalent for arzoxifene (particularly 20 mg) than for controls. For 58 evaluable women in Phase IB, a decrease in estrogen receptor expression for arzoxifene was observed compared with no change with placebo (P = 0.0068). However, decreases in proliferation indices for arzoxifene were not statistically different from placebo, perhaps due to a confounding effect of stopping hormone replacement therapy before entry. CONCLUSION: Given the favorable side effect profile and the biomarker modulations reported here, arzoxifene remains a reasonable candidate for additional study as a breast cancer chemoprevention agent.

Anticarcinogenic Agents↗
PubMed2004

Bayesian sample size calculations in phase II clinical trials using informative conjugate priors.

A number of researchers have discussed phase II clinical trials from a Bayesian perspective. A recent article by Tan and Machin focuses on sample size calculations, which they determine by specifying a diffuse prior distribution and then calculating a posterior probability that the true response will exceed a prespecified target. In this article, we extend these sample size calculations to include informative prior distributions using various strategies that allow researchers with both optimistic and pessimistic priors direct involvement in the sample size decision making. We select the informative priors via multiple methods determined by the mean, median or mode of the conjugate prior. These cases can result in varying sample sizes.

Bayes Theorem↗
PubMed2004

Predictors of smoking cessation among African-Americans enrolled in a randomized controlled trial of bupropion.

OBJECTIVES: Identification of individual characteristics that predict successful smoking cessation treatment has been limited to studies with mostly white participants. This study identifies factors that predict successful quitting among African-Americans participating in a smoking cessation trial. METHODS: Twenty-one baseline variables were analyzed as potential predictors from a double-blind placebo-controlled, randomized trial that used bupropion SR for smoking cessation among 600 African-American smokers. Chi-square tests, two sample t tests, and multiple logistic regression procedures were employed to identify predictors of 7-day abstinence among the 535 participants who completed the 7-week medication phase. RESULTS: Univariate predictors of cessation were receiving bupropion (P < 0.0001), not smoking menthol cigarettes (P = 0.0062), smoking after 30 min of waking (P < 0.0001), older age (P = 0.0085), smoking fewer cigarettes per day (P = 0.0038), and lower cotinine levels (P = 0.0002). Logistic regression identified three significant independent predictors. Participants who received bupropion treatment were more than twice as likely to quit smoking at the end of treatment compared to participants who received placebo (OR = 2.62; 95% CI = 1.77-3.88, P < 0.0001), while smoking within 30 min of waking (OR = 0.40; 95% CI = 0.25-0.62, P < 0.0001) and higher salivary cotinine levels at baseline (OR = 0.799; 95% CI = 0.629-0.922, P < 0.0001) reduced the likelihood of quitting. CONCLUSIONS: This is the first report identifying predictors of smoking cessation among African-Americans participating in a clinical trial. Results indicate that, aside from bupropion treatment, various indicators of addiction were the strongest predictors. While this is similar to findings among white smokers, thresholds of addiction may need to be adjusted for African-American smoking patterns. Additional studies focused on diverse populations are needed to improve treatment approaches and to identify population-specific factors that are important for treatment-matching approaches.

Adult↗
PubMed2004

Mammography facility characteristics and repeat mammography use among Medicare beneficiaries.

BACKGROUND: The goal of this study was to examine mammography facility characteristics and explore how such characteristics may impact repeat mammography use. METHODS: Mammography facility characteristics were obtained through a mailed a 21-item survey to Kansas mammography facilities. Medicare mammography claims were used to calculate facility-specific repeat mammography rates. Administrative data included female Kansas beneficiaries aged 65 years and older (N = 39,035) with a baseline mammogram during 1999. Beneficiaries with a mammography claim 12-18 months after their baseline mammogram were deemed to have had a repeat mammogram. RESULTS: Completed surveys were received from 90% (N = 79) of the 97 facilities serving >10 beneficiaries. Most facilities were in rural communities (58%), had an on-site radiologist (58%), and mailed mammography reminders to patients (63%). Extended hours of operation and the acceptance of self-referrals were uncommon (33% and 37%, respectively). Few facilities employed a quality improvement team (33%) or measured annual patient return rates (18%), but many measured patient satisfaction (57%). Of the beneficiaries, 61% had a repeat mammogram during the subsequent 12-18 months (range, 0% to 84%). Facilities notifying primary care providers of patients due for mammograms had higher repeat mammography rates. Multiple regression analyses found that higher repeat mammography rates were associated with facilities that accepted self-referrals, measured patient satisfaction, were in urban areas, and served a larger proportion of white beneficiaries. CONCLUSION: Mammography facility characteristics and repeat mammography rates vary widely. Although modifiable facility characteristics that may influence repeat mammography need additional study, results from this study indicate that mammography facilities are an opportunistic arena for quality improvement endeavors.

Adult↗
PubMed2004

Association of platelet-derived growth factor-B chain with simian human immunodeficiency virus encephalitis.

Chemokines and cytokines play a critical role in HIV infection, serving both to modulate virus replication and to recruit target cells to the site of infection. Platelet-derived growth factor (PDGF), a mitogen and chemoattractant for a wide variety of cells, is secreted by macrophages. Since macrophages are the target cells for lentiviral infection in the brain and PDGF is a known inducer of macrophage chemoattractant protein-1 (MCP)-1, a potent chemokine closely associated with HIV encephalitis, we investigated the association of PDGF-B chain (PDGF-B) with encephalitis in macaques caused by simian human immunodeficiency virus (SHIV), a chimera of HIV and SIV. Northern blot analysis confirmed elevated expression of PDGF-B chain mRNA in the brains from encephalitic macaques. Validation of these in vivo studies was confirmed in rhesus macrophage cultures infected with SHIV(KU2) in which we demonstrated heightened expression of PDGF-B chain mRNA. Nuclear run-off analysis established transcriptional up-regulation of PDGF-B chain in virus-inoculated macrophage cultures. Reciprocally, addition of exogenous PDGF enhanced virus replication and MCP-1 expression in these cells. Inhibition of virus replication by tyrosine kinase inhibitor, STI-571, and by PDGF-B antisense oligonucleotides confirmed the specificity of the PDGF effect. Relevance of these findings was confirmed by analysis of archival brain tissue from SHIV encephalitic and non-encephalitic macaques for PDGF-B chain expression. PDGF-B chain protein expression was observed in the virus-infected cells in microglial nodules in the brains of SHIV-encephalitic macaques.

Animals↗
PubMed2004

The prevalence of Barrett's esophagus and erosive esophagitis in patients undergoing upper endoscopy for dyspepsia in a VA population.

The purpose of this study was to establish the prevalence of Barrett's esophagus and erosive esophagitis in a group of patients undergoing upper endoscopy for dyspepsia. Computerized endoscopy records were retrospectively evaluated to identify patients who underwent upper endoscopy for dyspepsia. Objective findings were recorded, including the presence of Barrett's esophagus, erosive esophagitis, and peptic ulcer disease. Among 264 patients, Barrett's esophagus was found in 16 (6.1%). The mean length of Barrett's was 2.0 cm, and the majority (81.3%) was short segment. Erosive esophagitis was found in 62 patients (23.%), and peptic ulcer disease was found in 25 patients (9.5%). Approximately 30% of patients undergoing endoscopy for dyspepsia had esophageal lesions. The prevalence of Barrett's in this population was 6%. Based on these results, a trial of acid suppression may benefit a third of patients with dyspepsia. Current screening practices for Barrett's in reflux patients alone may need to be reevaluated.

Adult↗
PubMed2004

Development of a culturally relevant body image instrument among urban African Americans.

OBJECTIVE: To validate a culturally relevant body image instrument among urban African Americans through three distinct studies. RESEARCH METHODS AND PROCEDURES: In Study 1, 38 medical practitioners performed content validity tests on the instrument. In Study 2, three research staff rated the body image of 283 African-American public housing residents (75% women, mean age = 44 years), with the residents completing body image, BMI, and percentage body fat measures. In Study 3, 35 African Americans (57% men, mean age = 42) completed body image measures and evaluated their cultural relevance. RESULTS: In Study 1, 97% to 100% of practitioners sorted the jumbled figures into the correct ascending order. The correlation between the body image figures and the practitioners' weight classifications of the figures was high (r = 0.91). In Study 2, observers arrived at similar ratings of body size with excellent consistency (alpha = 0.95). Ratings of body image were strongly correlated with participant BMI (r = 0.89 to 0.93 across observers and 0.81 for all participants) and percentage of body fat (r = 0.77 to 0.89 across observers and 0.76 for all participants). In Study 3, body image ratings with the new scale were positively correlated with other validated figural scales. The majority of participants reported that figures in the new body image scale looked most like themselves and other African Americans and were easiest to identify themselves with. DISCUSSION: The instrument displayed strong psychometric performance and cultural relevance, suggesting that the scale is a promising tool for examining body image and obesity among African Americans.

Adult↗
PubMed2004

ADH1B*1, ADH1C*2, DRD2 (-141C Ins), and 5-HTTLPR are associated with alcoholism in Mexican American men living in Los Angeles.

BACKGROUND: The aim of the present study was to use a candidate gene approach to identify the genetic risk factors for alcoholism in Mexican Americans residing in the Los Angeles area. The genes selected include alcohol metabolizing genes and neurotransmitter genes, which have been shown in the literature to be associated with alcoholism in other ethnic groups. METHODS: Thirteen allelic variants from seven genes were evaluated for their role in alcoholism using alcoholic (n = 200) and nonalcoholic (n = 251) Mexican Americans. Those polymorphic sites include alcohol dehydrogenase (ADH1B, ADH1C), aldehyde dehydrogenase (ALDH2), cytochrome P-450 2E1 (CYP2E1) TaqI, DraI, RsaI, dopamine D2 receptor (DRD2) TaqI A, B, intron 6, exon 7, -141C Ins/Del, serotonin transporter (5-HTTLPR), and GABAA receptor beta3 subunit (GABRbeta3). RESULTS: The results demonstrate that Mexican Americans have extremely low allele frequency for both ALDH2*2 and ADH1B*2 and a relatively high frequency of ADH1C*2 and CYP2E1 c2 alleles. ADH1B*1, ADH1C*2, DRD2 (-141C Ins), and 5-HTTLPR were associated with alcoholism in Mexican Americans (p < 0.05). DRD2 Ins was associated with alcoholism in those alcoholics who carried the ADH1B*2 or ADH1C*1 protective alleles (p = 0.032 in genotype level and p = 0.015 in allele level). DRD2 TaqI A and B alleles were associated with early age of onset for drinking (p = 0.016 for TaqI A1 and p = 0.049 for TaqI B1 allele). CONCLUSIONS: Together, the data reveal unique genetic patterns in Mexican Americans that may be in part responsible for the heightened risk for alcoholism and alcohol-associated health problems in this population.

Adult↗
PubMed2004

Detection of cardia intestinal metaplasia: do the biopsy number and location matter?

BACKGROUND AND AIM: Presence of intestinal metaplasia in the gastric cardia (cardia intestinal metaplasia, CIM) has been reported in 5-34% of patients undergoing upper endoscopy and is a topic of interest given the rising incidence of cancer in this location. The aim of this article is to determine the prevalence of CIM in biopsies obtained from two separate locations within the gastric cardia. METHODS: Patients presenting to the endoscopy unit for upper endoscopy for any symptoms were invited to participate in the study. The biopsy protocol included: eight biopsies from the gastric cardia, four from upper cardia (forceps across the squamocolumnar junction), four from lower cardia (within 1 cm of upper cardia), and four each from the gastric body and antrum. All cardia biopsies were stained with hematoxylin and eosin (H&E) and alcian blue at pH 2.5 for the presence of goblet cells and the body/antrum biopsies were stained with Steiner silver stain for Helicobacter pylori detection. In patients testing negative for H. pylori by histology, a serology test was performed. RESULTS: Sixty-five patients have been evaluated by this protocol; median age 54 yr (range: 34-81 yr), 63 males, 53 Caucasians, and 12 African Americans. The detection of CIM was as follows: upper cardia only, 7, both upper and lower cardia, 5, and lower cardia only, 7. Thus, CIM was detected in 12 patients (18%) in the upper cardia biopsies, in 12 patients (18%) in the lower cardia; overall prevalence of CIM was 29% (19 patients). Fifty-eight percent of CIM patients tested positive for H. pylori by either histology or serology. The addition of serology allowed for the detection of eight additional H. pylori-positive CIM patients. CONCLUSIONS: The prevalence of CIM in this study was similar (18%, four biopsies) at each location; however, if both locations were considered (eight biopsies), the prevalence increased to 29%. Thus, CIM prevalence may vary depending on the number of biopsies obtained as well as on the location of biopsies. Use of additional testing detects more patients who are H. pylori positive and should be performed if association of CIM with H. pylori is contemplated. Future endoscopic studies of the gastric cardia should specify the location of biopsies, the number of biopsies obtained, and the tests used to diagnose H. pylori.

Adult↗
PubMed2003

Does menthol attenuate the effect of bupropion among African American smokers?

BACKGROUND: African Americans have higher tobacco-related morbidity and mortality and are more likely to smoke menthol cigarettes than their white counterparts. This study examined differences between African American menthol and non-menthol smokers in smoking characteristics and cessation. METHODS: The study sample consisted of 600 African American smokers enrolled in a clinical trial that assessed the efficacy of sustained-release bupropion for smoking cessation. Menthol (n = 471) and non-menthol (n = 129) smokers were compared on smoking-related characteristics and abstinence rates at 6 weeks and 6 months. RESULTS: Menthol smokers were younger (41.2 versus 52.9 years), more likely to be female (73.7% versus 56.6%) and more likely to smoke their first cigarette within 30 minutes of waking up (81.7% versus 69.8%) compared to non-menthol smokers (all P < 0.01). Cigarette taste (50% versus 40%, P = 0.054) was rated non-significantly higher by menthol smokers. Seven-day point-prevalence abstinence from smoking at 6 weeks were 28% and 42% (P = 0.006) and at 6 months were 21% and 27% (P = 0.21) for menthol and non-menthol smokers, respectively. At 6 weeks follow-up, stepwise logistic regression revealed that among those younger than 50 years, non-menthol smokers were more likely to quit smoking (odds ratio = 2.0; 95% CI = 1.03-3.95) as were those who received bupropion (odds ratio = 2.12; 95% CI = 1.32-3.39). CONCLUSION: African American menthol smokers had lower smoking cessation rates after 6 weeks of treatment with bupropion-SR, thereby putting menthol smokers at greater risk from the health effects of smoking. Lower overall cessation rates among African Americans menthol smokers may partially explain ethnic differences in smoking-related disease risks.

Adult↗
PubMed2003

Duration of television watching is associated with increased body mass index.

OBJECTIVE: To assess the effect of television viewing on subsequent change in body mass index (BMI=kg/m(2)) percentiles (BMI%) in adolescence. STUDY DESIGN: Data were drawn from the California Teen Longitudinal Survey of adolescents 12 to 17 years old with baseline assessment in 1993 and follow-up in 1996. Self-reported height and weight were used to calculate BMI and derive age-specific and sex-specific BMI%. Hours of television watched per day were obtained at baseline (BTV). The relations of BTV and BMI percentiles both at baseline and after 3 years were assessed with linear regression modeling. RESULTS: Of 2223 adolescents (52% male, 68% white), 5.85% (n=130) were overweight (BMI > or =95th percentile) at baseline and 5.40% (n=120) at follow-up. Mean BTV was 2.85 (SD, 1.98). In adjusted models, with each additional hour of BTV, the baseline BMI% increased by.9, and the follow-up BMI% increased by.47. Adolescents who watched more than 2 hours of television a day were twice as likely to be overweight at follow-up as adolescents who watched < or =2 hours. CONCLUSIONS: Television viewing leads to a subsequent increase in BMI percentiles and overweight. Efforts to decrease overweight should consider interventions to reduce television time.

Adolescent↗
PubMed2003

Successful recruitment of minorities into clinical trials: The Kick It at Swope project.

Ethnic minorities are often underrepresented in clinical trials, and their recruitment can challenge researchers. Developing and communicating effective and efficient recruitment strategies may help researchers enroll more minorities into research studies. Kick It at Swope was a double-blind, randomized trial that evaluated bupropion for smoking cessation among 600 adult African Americans who smoked 10 or more cigarettes a day. Proactive recruitment strategies (in-person appeals by study staff and health care providers) and reactive recruitment strategies (disseminating information that asked people to call a study hotline) were implemented sequentially in an additive fashion over 16 months. Resulting patterns of recruitment are described and the two phases are compared based on their relative effectiveness, efficiency, and cost. More enrollees were recruited in the reactive phase (n=534) than in the proactive phase (n=66). Those recruited in the reactive phase were more likely to be eligible (OR=4.8) and more likely to be enrolled (OR=4.2) than those recruited in the proactive phase. Participants recruited in the reactive phase reported significantly higher levels of education and income, better health, and significantly lower indicators of depression and life hassles, compared with those recruited in the proactive phase. The reactive recruitment phase was less expensive than the proactive recruitment phase (22 US Dollars/enrollee vs. 159 US Dollars/enrollee). Reactive recruitment strategies added to multiple proactive clinic-based recruitment strategies were more effective, more efficient, and less costly than proactive recruitment alone. Close monitoring combined with the use of multiple recruitment methods and flexible recruitment plans can lead to successful, efficient, and low-cost recruitment of minorities into clinical trials.

Adult↗
PubMed2003

Gastric function in the elderly: effects on absorption of ketoconazole.

The authors studied effects of age-related changes in gastric function on absorption of ketoconazole. Eighteen men and women age 65 years or older swallowed 200 mg ketoconazole on two occasions, once as tablets with water and once as tablets crushed in acidic juice. The sequence was randomly determined. Gastric pH was measured by radiotelemetry and gastric emptying rate by radiolabeled technetium with a gamma camera. Plasma ketoconazole was assayed by high-performance liquid chromatography (HPLC). Subjects with gastric pH less than or equal to 4.5 absorbed ketoconazole equally well from intact tablets and tablets crushed in acid. When pH was 5.0 or higher, ketoconazole was absorbed well from acid-crushed tablets but not from intact tablets. Gastric emptying was shown to be rapid in all subjects. Since the prevalence of such hypoacivity is approximately 5% in the elderly, and other parameters of gastric function are usually normal, impaired absorption of drugs such as ketoconazole should be uncommon with normal aging.

Administration, Oral↗
PubMed2002

A comparison of prognostic tumor markers obtained on image-guided breast biopsies and final surgical specimens.

BACKGROUND: This study was initiated to determine whether tumor markers obtained on image-guided breast biopsy specimens provide accurate prognostic information for women with invasive breast cancer. METHODS: Prognostic tumor markers on preoperative image-guided biopsy and final surgical specimens were compared in 44 patients with invasive breast cancer. RESULTS: Progesterone receptor (PR) discordance was 18%. In 87% of PR discordant cases, the image-guided biopsy was positive and the final specimen was negative (P = 0.03). Tumor grade was discordant in 36% of patients Discordance for estrogen receptor (ER) = 2%; MIB-1 = 18%; Her2/neu = 9%; EGFR = 10%; p53 = 9%; and bcl-2 = 0%. The discordance for these markers was random and did not reach statistical significance. CONCLUSION: Image-guided core needle biopsies provide reliable information for the majority of prognostic tumor makers. A positive progesterone receptor is significantly more likely to be determined by core biopsy rather than the final surgical specimen. Tumor grade should be based upon the final surgical specimen whenever possible.

Aged↗