Search PubMed⌕ Search

Biomedical subjects

R R Love

Publications and source records attributed to R R Love.

At least 37 records · Page 2Linked to original sources
PubMed1996

Toxicity evaluation of difluoromethylornithine: doses for chemoprevention trials.

This intergroup trial was developed to determine the toxicity of relatively low doses of difluoromethylornithine (DFMO) administered to humans for 1 year. The goal was to find an appropriate DFMO dose for use in human chemoprevention trials. Patients with resected superficial bladder cancers were studied. Following stratification, they were randomized to daily DFMO doses of 0.125, 0.25, 0.5, or 1.0 g/day for a planned period of 1 year. Patients were followed closely for evidence of drug toxicity. Seventy-six patients were evenly randomized (19 per group) to receive each dose of DFMO. Forty-nine patients received DFMO for more than 200 days while 35 received the drug for > or = 350 days. No substantial drug-related toxicity was observed at any dose. DFMO doses of > or = 1 g/day for periods up to 1 year appear to be without significant toxicity in most patients. This dose range may be appropriate for use in future human cancer chemoprevention trials.

Antineoplastic Agents↗
PubMed1995

Assessing breast self-examination.

BACKGROUND: Women practice breast self-examination (BSE) according to their own schedule and skill. This variation in how BSE is performed has complicated the interpretation of studies of BSE efficacy and utilization. METHODS: We compared two methods commonly used to assess BSE competency, self-report of practice and ability to detect lumps in a model, among 81 women participating in a controlled toxicity trial of tamoxifen. Subjects were postmenopausal, were under 65 years of age, and had a history of breast cancer within the past 10 years but were currently free of disease. Women were asked to describe their usual BSE practice and were assigned a score (0-10) based on the number of recommended techniques and positions mentioned. Subjects were then instructed to examine a silicone breast model embedded with lumps (HealthEdCo) and to report any abnormalities. RESULTS: Overall proficiency was low by both measures. No significant correlation (r = 0.16, P = 0.15) was found between the two measures of proficiency. Higher correlations were observed among older women and among those practicing BSE monthly. CONCLUSIONS: This study suggests that the two techniques are not comparably evaluating BSE proficiency. Further, both of these methods are likely to be poor measures of true BSE practice.

Aged↗
PubMed1995

Thyroid function test changes with adjuvant tamoxifen therapy in postmenopausal women with breast cancer.

PURPOSE: While tamoxifen has been shown to alter concentration of many hormones and their binding globulins, there have been conflicting results regarding its effects on thyroid function tests. We sought to clarify these effects by studying subjects in a controlled clinical trial. PATIENTS AND METHODS: We evaluated a subset of postmenopausal women who had participated in a longitudinal, double-blind, randomized, placebo-controlled toxicity study of tamoxifen 10 mg orally, twice daily. There were 14 subjects in both the tamoxifen and placebo groups. Measurement of thyroid-binding globulin (TBG), thyroxine uptake (T-Uptake), thyroxine (T4), and thyroid-stimulating hormone (TSH), and an indirect estimate of the free T4 index (FTI), were made for each subject before and after 3 months of treatment. RESULTS: For T-Uptake, T4, and TBG, there were significant increases in the mean change from baseline to 3 months in the tamoxifen group compared with the placebo group (P = .02, .0001, and .003, respectively), while there were no significant changes in the measured TSH and in the calculated FTI. CONCLUSION: We conclude that tamoxifen therapy in postmenopausal women results in increased TBG, with secondary increases in measured T-Uptake and T4 following. However, TSH and FTI levels are unchanged, and treated women remain eumetabolic.

Breast Neoplasms↗
PubMed1995

Clinical review 70: Approaches to the prevention of breast cancer.

In the face of an apparently increasing incidence of postmenopausal breast cancer, and with frustratingly limited gains in treatment, significant possibilities for widespread prevention of breast cancer must be vigorously explored. However, progress with this approach has been painfully slow, and the multifactorial etiology of breast cancer development is most responsible for this delay. The challenges in our approaches are to recognize the major differences between treatment and prevention and to demand a comprehensive biological rationale, an absence of serious toxic effects and likely long-term acceptability to women of interventions coming to definitive clinical trial.

Breast Neoplasms↗
PubMed1995

Are clinicians intervening with their patients who smoke? A "real-world" assessment of 45 clinics in the upper Midwest.

OBJECTIVE: To determine the level of intervention provided by primary care physicians to individuals who smoke. SETTING: 45 primary care clinics throughout the upper Midwest. PATIENTS: 6,086 men and women (M:F = 1:2), ages 50 to 68, who sought medical care at any one of the 45 primary care clinics and completed two questionnaires regarding preventive medical services received during the previous 3 years (1990-1993). RESULTS: Of patients who smoke, 92% reported that their clinician had asked about their smoking status. Additionally, 86% reported being informed at their clinic of the dangers of tobacco use. A smaller percentage of individuals (60.1%) reported being explicitly advised on how to quit, and fewer still (27.2%) reported being referred to a stop smoking program. CONCLUSIONS: While most clinicians inquire about their patients' smoking status and recommend they quit, there currently exists a deficiency in the translation of these recommendations into concise, explicit instructions on how to quit. By increasing the frequency of clinicians giving specific advice about how to quit, the overall success rate of the public health campaign against tobacco use will be greatly enhanced.

Aged↗
PubMed1994

Effect of tamoxifen on lumbar spine bone mineral density in postmenopausal women after 5 years.

BACKGROUND: Because adjuvant tamoxifen citrate is given to women with early-stage breast cancer for long periods, it is important to know how it affects risk factors for osteoporotic bone fractures, particularly since rates of bone fracture increase rapidly with age in postmenopausal women. In a 2-year randomized placebo-controlled toxicity study in 140 subjects, we demonstrated that tamoxifen was associated with preservation of bone mineral density (BMD), a major risk factor for fractures, in the lumbar spine. METHODS: Five years after entry on this study we reexamined 62 of the original subjects with lumbar spine BMD and serum osteocalcin measurements. These were women available for study because they had not suffered major illnesses and had continued to receive (1) tamoxifen or (2) the no-tamoxifen regimen that they had originally been randomized to receive for the entire 5 years. RESULTS: For lumbar spine BMD at baseline, the 30 subjects in the long-term tamoxifen group and the 32 subjects in the long-term no-tamoxifen group were not significantly different (P = .26). During the first 2 years of follow-up, the 30 subjects in the long-term tamoxifen group showed the same BMD pattern as the entire 70-patient tamoxifen cohort, and similarly the 32 subjects in the long-term no-tamoxifen group showed the same pattern as the entire 70-patient cohort who received placebo. Five-year mean BMD measurements for each long-term follow-up group showed no significant changes from their respective 2-year levels. However, 5-year BMD measurements between the two groups differed (tamoxifen group, +0.8%; placebo group, -0.7%) (P = .06), and the mean regression lines for the changes in BMD over 5 years differed significantly between the two groups (P = .0005). Adjustment for differences in body mass index, reported exercise, and calcium supplementation between these two groups did not change these results. Osteocalcin levels, also comparable at baseline in the two groups, were significantly lower in tamoxifen-treated subjects at 5 years (P = .0005). CONCLUSIONS: While remodeling of bone may be lower, resorption of lumbar spine bone mineral is also lower, and tamoxifen preserves BMD in the lumbar spine over 5 years of treatment in postmenopausal women. Over longer periods, this preservation of BMD might be expected to be associated with lower fracture rates.

Bone Density↗
PubMed1994

Effects of tamoxifen on cardiovascular risk factors in postmenopausal women after 5 years of treatment.

BACKGROUND: Adjuvant tamoxifen therapy for breast cancer has been given for a period of several years. Cardiovascular diseases increased in incidence rapidly in women older than 60 years. Favorable changes in cardiovascular risk factors have been seen with 2 years of tamoxifen therapy, and lower rates of myocardial infarction and of hospitalization for heart disease have been observed in tamoxifen-treated women. PURPOSE: We sought to evaluate changes in risk factors for cardiovascular diseases in postmenopausal women after therapy with tamoxifen for 5 years. METHODS: Five years after their initial entry in a 2-year randomized, placebo-controlled toxicity study, we re-examined 62 of the original 140 disease-free, axillary node-negative postmenopausal breast cancer patients. These 62 patients were women available for study because they had not suffered major illness and had continued on either the tamoxifen or no-tamoxifen regimen to which they had been originally randomly assigned for the entire 5 years. Patient and control blood samples were analyzed for total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol and subfractions, triglycerides, apolipoprotein AI, apolipoprotein B, lipoprotein(a), fibrinogen, glucose, and platelets. RESULTS: At base line for all measurements except atherogenic lipoprotein [lipoprotein(a)], the 30 long-term tamoxifen recipients and the 32 long-term no-tamoxifen recipients were not significantly different. After 5 years, levels of total serum cholesterol (P < .001), LDL cholesterol (P < .001), and lipoprotein(a) (P = .001) were significantly lower, and apolipoprotein AI levels were significantly higher (P < .001) in the tamoxifen-treated group compared with the no-tamoxifen group. Apolipoprotein B levels increased to a greater extent in the no-tamoxifen than in the tamoxifen group (P < .001). After 5 years, fibrinogen level decrease and triglyceride level increases in the tamoxifen group compared with the no-tamoxifen group were of borderline statistical significance and HDL cholesterol levels were not different in the two groups. CONCLUSION: Favorable changes in lipid, lipoprotein, and fibrinogen levels seen early in tamoxifen therapy in postmenopausal women persist with treatment of 5 years. IMPLICATIONS: The types and magnitude of changes in cardiovascular risk factors seen here with tamoxifen are similar to a certain extent with those seen with estrogen supplements. Further risk-factor and ethnic-group data are needed to estimate the magnitude of expected benefits of tamoxifen treatment on incidence of heart disease.

Blood Glucose↗
PubMed1994

Cancer prevention through health promotion. Defining the role of physicians in public health.

In recent years a major focus in the delivery of cancer prevention services has been on the actions of physicians in ambulatory care practice. Whereas delivery of these services has increased markedly, it is likely that physician actions overall are not producing expected measurable benefits to whole populations. The level and quality of prevention services will be increased through greater local consensus regarding cancer prevention goals, better organization to provide these services more efficiently, and improved health education in clinics. But the greatest challenge is to increase access for all Americans to these services. Access to health services is not only a medical problem. Social problems of unemployment, poverty, and limited education significantly influence access to services and good health in poorly understood ways. While encouraging direct approaches to addressing social problems in the medical community, the agenda for the future in cancer prevention must be concerned with facilitating a public health community responsibility attitude among physicians and with fostering development of hospital/community/physician partnerships in which community organizations have significant ownership. Overall public health indices in cancer can improve only with greater attention to access and the broad societal issues of preventive medicine.

Health Promotion↗
PubMed1994

Protein S and protein C level changes with adjuvant tamoxifen therapy in postmenopausal women.

Tamoxifen citrate is a synthetic antiestrogen that provides survival benefit when given as adjuvant treatment in postmenopausal women with breast cancer. Venous thrombophlebitis may complicate tamoxifen treatment at a rate of approximately one per 800 treatment-years. To explore the possible procoagulant effects associated with tamoxifen therapy we evaluated changes in protein S and C activity levels in 58 postmenopausal women with surgically resected breast cancer who were disease-free and participating in a double-blind, placebo-controlled, randomized toxicity study of tamoxifen. The changes in protein C activities for the tamoxifen group (mean level = 113%) compared to those in the placebo group (mean level = 115%) were not significant (p = 0.45). Protein S activity levels increased while protein C activity levels decreased from baseline at 24 months in both tamoxifen and placebo groups. We conclude that the possible thrombophlebitis-promoting effect of tamoxifen in postmenopausal women is unlikely to be explained on the basis of protein S and protein C activity level changes.

Breast Neoplasms↗
PubMed1994

Prevention of breast cancer in premenopausal women.

While all-inclusive complete models for breast cancer development are not available, four concepts are likely to be critical to creation of well-grounded breast cancer prevention efforts: 1) step-by-step progressive development, 2) involving multiple factors, 3) over several years, and 4) during a long period of which the process may be reversible. Interventions to prevent breast cancer must have a comprehensive biological rationale, an absence of serious toxic effects, and long-term acceptability by women. Prophylactic mastectomy may be beneficial in some women, but identification of individuals at very high risk for breast cancer remains elusive. At present, greater attention to four manipulable risk factors is appropriate: radiation, smoking, alcohol, and lactation. Clinical trials are in the process of studying a synthetic retinoid (4-hydroxyphenylretinamide), tamoxifen, and a low-fat diet. Other breast cancer prevention strategies in various phases of preclinical trial evaluation include: pseudopregnancy, an "ideal" combination oral contraceptive, luteinizing hormone-releasing hormone (LHRH) agonist oophorectomy, modification of estrogen metabolism, suppression of ornithine decarboxylase induction, and manipulation of growth factors.

Adult↗