Search PubMed⌕ Search

Biomedical subjects

A B Miller

Publications and source records attributed to A B Miller.

At least 55 records · Page 3Linked to original sources
PubMed2001

Risk factors for injuries and falls among adults with developmental disabilities.

The present study was designed to identify risk factors for injuries including falls and non fall-related injuries among adults with developmental disabilities. The following variables were examined as potential risk factors: age, gender, level of intellectual disability, health, seizures, ambulatory status, adaptive and maladaptive behaviours, use of antipsychotic drugs, and type of residential setting. The subjects were 268 adults with developmental disabilities > or = 30 years of age. A total of 30 participants (11%) were reported to have injuries. Over 50% of injuries were caused by falls. Individuals who had a higher frequency of seizures, had more destructive behaviour and used antipsychotic drugs had the highest risk of injuries. A sub-analysis of fall-related injuries indicated that individuals who were > or = 70 years of age, ambulatory and had a higher frequency of seizures had the highest risk of injurious falls. Adaptive behaviour, destructive behaviour and physical health were positively related to non-fall-related injuries. Individuals with developmental disabilities who have better health and greater adaptive behaviour may be more active, and therefore, at an increased risk of non-fall-related injuries.

Accidental Falls↗
PubMed2001

Intermediate histological effect markers for breast cancer.

The evidence that ductal carcinoma of the breast (DCIS) is an obligate precursor of invasive breast cancer and thus qualifies as an intermediate effect marker in chemoprevention research is reviewed. Much of the evidence on the natural history of DCIS has been derived from the era before the introduction of mammographic screening. Thus it may not be applicable in the present situation when women are likely to be under mammographic surveillance in chemoprevention trials. Further, the data that are becoming available from breast screening trials suggest that at least over follow-up periods now exceeding a decade, detection and treatment of DCIS has no impact on subsequent incidence of breast cancer. Although there are some indications that other biomarkers of malignancy are expressed similarly in DCIS and invasive cancer of similar grade, this evidence may not be sufficient to allow exclusive reliance on DCIS as an intermediate-effect marker in chemoprevention research.

Biomarkers, Tumor↗
PubMed2000

An international evaluation of the cancer-preventive potential of sunscreens.

The IARC convened a working group of experts in Lyon, France, on 10-18 April, 2000, to evaluate the cancer-preventive activity of sunscreens and to compile the fifth volume of the IARC Handbooks of Cancer Prevention. The working group concluded that the topical use of sunscreens reduces the risk of sunburn in humans and that sunscreens probably prevent squamous-cell carcinoma of the skin when used mainly during unintentional sun exposure. No conclusion can be drawn about the cancer-preventive activity of topical use of sunscreens against basal-cell carcinoma and cutaneous melanoma. Use of sunscreens can extend the duration of intentional sun exposure, such as sunbathing. Such an extension may increase the risk for cutaneous melanoma. The working group warned against relying solely on sunscreens for protection from UV radiation.

Basal Cell Carcinoma↗
PubMed2000

Canadian National Breast Screening Study-2: 13-year results of a randomized trial in women aged 50-59 years.

BACKGROUND: Screening for breast cancer with mammography in women aged 50 years or more has been shown to reduce mortality from breast cancer. However, the extent to which mammography contributes to the reduction of mortality in women who also undergo physical examination of the breasts is not known. This study was designed to compare breast cancer mortality following annual screening consisting of two-view mammography and physical examination of the breasts with mortality following annual screening by physical examination only. Breast self-examination was taught to all participants. METHODS: This trial randomly and individually assigned 39 405 women aged 50-59 years, recruited from January 1980 through March 1985, to one of the study arms. The women were followed by record linkage with the Canadian National Cancer Registry and National Mortality Database to December 31, 1993, and by active follow-up of breast cancer patients to June 30, 1996. RESULTS: Randomization achieved virtually equal distribution of demographic and breast cancer risk variables. At the first annual screen, 21% of the cancers found by mammography alone (in the mammography plus physical examination group) were 20 mm or more in size compared with 46% of those found by physical examination in the mammography plus physical examination group and 56% in the physical examination-only group. The corresponding percentages for screens 2-5 were 10%, 42%, and 50%, respectively. Screening detected 267 invasive breast cancers in the mammography plus physical examination group compared with 148 in the physical examination-only group. By December 31, 1993, 622 invasive and 71 in situ breast carcinomas were ascertained in the mammography plus physical examination group, and 610 and 16 were ascertained in the physical examination-only group. At 13-year follow-up, with 107 and 105 deaths from breast cancer in the respective groups, the cumulative rate ratio was 1.02 (95% confidence interval = 0.78-1.33). CONCLUSION: In women aged 50-59 years, the addition of annual mammography screening to physical examination has no impact on breast cancer mortality.

Breast Neoplasms↗
PubMed2000

Pooled analysis of prospective cohort studies on height, weight, and breast cancer risk.

The association between anthropometric indices and the risk of breast cancer was analyzed using pooled data from seven prospective cohort studies. Together, these cohorts comprise 337,819 women and 4,385 incident invasive breast cancer cases. In multivariate analyses controlling for reproductive, dietary, and other risk factors, the pooled relative risk (RR) of breast cancer per height increment of 5 cm was 1.02 (95% confidence interval (CI): 0.96, 1.10) in premenopausal women and 1.07 (95% CI: 1.03, 1.12) in postmenopausal women. Body mass index (BMI) showed significant inverse and positive associations with breast cancer among pre- and postmenopausal women, respectively; these associations were nonlinear. Compared with premenopausal women with a BMI of less than 21 kg/m2, women with a BMI exceeding 31 kg/m2 had an RR of 0.54 (95% CI: 0.34, 0.85). In postmenopausal women, the RRs did not increase further when BMI exceeded 28 kg/m2; the RR for these women was 1.26 (95% CI: 1.09, 1.46). The authors found little evidence for interaction with other breast cancer risk factors. Their data indicate that height is an independent risk factor for postmenopausal breast cancer; in premenopausal women, this relation is less clear. The association between BMI and breast cancer varies by menopausal status. Weight control may reduce the risk among postmenopausal women.

Adult↗
PubMed2000

A geminivirus replication protein interacts with the retinoblastoma protein through a novel domain to determine symptoms and tissue specificity of infection in plants.

Geminiviruses replicate in nuclei of mature plant cells after inducing the accumulation of host DNA replication machinery. Earlier studies showed that the viral replication factor, AL1, is sufficient for host induction and interacts with the cell cycle regulator, retinoblastoma (pRb). Unlike other DNA virus proteins, AL1 does not contain the pRb binding consensus, LXCXE, and interacts with plant pRb homo logues (pRBR) through a novel amino acid sequence. We mapped the pRBR binding domain of AL1 between amino acids 101 and 180 and identified two mutants that are differentially impacted for AL1-pRBR interactions. Plants infected with the E-N140 mutant, which is wild-type for pRBR binding, developed wild-type symptoms and accumulated viral DNA and AL1 protein in epidermal, mesophyll and vascular cells of mature leaves. Plants inoculated with the KEE146 mutant, which retains 16% pRBR binding activity, only developed chlorosis along the veins, and viral DNA, AL1 protein and the host DNA synthesis factor, proliferating cell nuclear antigen, were localized to vascular tissue. These results established the importance of AL1-pRBR interactions during geminivirus infection of plants.

Antigens, Polyomavirus Transforming↗
PubMed2000

Leukemia in electric utility workers: the evaluation of alternative indices of exposure to 60 Hz electric and magnetic fields.

BACKGROUND: Epidemiological studies have inconsistently demonstrated a positive relationship between magnetic and/or electric fields and leukemia. Although exposure to both 60 Hz electric and magnetic fields can be characterized in many ways, to date, risk assessment has been performed by using only a limited number of exposure indices. METHODS: The associations between adult leukemia and indices of electric and magnetic fields were explored within a nested case-control study of 31,453 Ontario electric utility workers. RESULTS: The percentage of time spent above electric field thresholds of 20 and 39 V/m was predictive of leukemia risk after adjusting for duration of employment and the arithmetic mean exposure to both electric and magnetic fields (P<0.05). Duration of employment was strongly associated with an increased risk of leukemia. Those who had worked for at least 20 years, and were in the highest tertiles of percentage of time spent above 10 and 20 V/m had odds ratios of 10.17 (95% CI = 1.58-65.30) and 8.23 (95% CI = 1. 24-54.43), respectively, when compared to those in the lowest tertile. Nonsignificant elevations in risk were observed between indices of magnetic fields and leukemia. CONCLUSIONS: Our results support the hypothesis that electric fields act as a promoting agent in the etiology of adult leukemia. Exposure assessment based on alternate indices of electric and magnetic fields should be incorporated into future occupational studies of cancer.

Adult↗
PubMed2000

Death review process in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial.

The procedures that have been adopted in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial are described. These procedures have been designed to ensure unbiased decisions on the underlying cause of death for all confirmed or suspected PLCO cancers. A death review committee with a nonvoting chair and three experienced reviewers as members has been appointed. After an initial pilot study, the procedures have been instituted and are working well.

Adult↗
PubMed2000

Circadian rhythm and sudden death in heart failure: results from Prospective Randomized Amlodipine Survival Trial.

OBJECTIVE: The purpose of this study was to address the timing of sudden death in advanced heart failure patients. BACKGROUND: Sudden death is a catastrophic event in cardiovascular disease. It has a circadian pattern prominent in the early AM, which has been thought to be due to a surge of sympathetic stimulation. We postulated that the distribution of events in advanced heart failure, with chronic sympathetic activation, would be more uniform implicating other potential mechanisms. METHODS: We analyzed data from Prospective Randomized Amlodipine Survival Trial (PRAISE). Sudden deaths were analyzed by time of death in 4-h and 1-h blocks for uniformity of distribution in the entire cohort, and in the prespecified ischemic and nonischemic stratum. Further analyses were undertaken in the treatment groups of amlodipine and placebo, and among those receiving background therapy of aspirin and warfarin. RESULTS: Sudden deaths in the overall cohort showed a nonuniform distribution with a PM peak but not an AM peak. The ischemic stratum also showed a PM peak, but sudden deaths within the nonischemic stratum were uniformly distributed. Neither amlodipine treatment nor aspirin or warfarin use altered the distribution. CONCLUSIONS: Sudden death in advanced heart failure did not show an AM peak, suggesting that circadian sympathetic activation did not strongly influence these events. The PM peak noted is likely complex in origin and was not affected by antiischemic or antithrombotic medications.

Adult↗
PubMed2000

Asymmetry in the PPARgamma/RXRalpha crystal structure reveals the molecular basis of heterodimerization among nuclear receptors.

The nuclear receptor PPARgamma/RXRalpha heterodimer regulates glucose and lipid homeostasis and is the target for the antidiabetic drugs GI262570 and the thiazolidinediones (TZDs). We report the crystal structures of the PPARgamma and RXRalpha LBDs complexed to the RXR ligand 9-cis-retinoic acid (9cRA), the PPARgamma agonist rosiglitazone or GI262570, and coactivator peptides. The PPARgamma/RXRalpha heterodimer is asymmetric, with each LBD deviated approximately 10 degrees from the C2 symmetry, allowing the PPARgamma AF-2 helix to interact with helices 7 and 10 of RXRalpha. The heterodimer interface is composed of conserved motifs in PPARgamma and RXRalpha that form a coiled coil along helix 10 with additional charge interactions from helices 7 and 9. The structures provide a molecular understanding of the ability of RXR to heterodimerize with many nuclear receptors and of the permissive activation of the PPARgamma/RXRbeta heterodimer by 9cRA.

Alitretinoin↗
PubMed2000

Alcohol and breast cancer mortality in a cohort study.

Available epidemiological evidence indicates that alcohol intake is associated with a higher risk of developing breast cancer. Plausible biological pathways include its effect on levels of estrogens, cell membrane integrity and cell-to-cell communication, inhibition of DNA repair, and congener effect. The present study evaluated the impact of alcohol on mortality from breast cancer, an area with relatively few studies in the literature. The subjects were participants in a Canadian prospective cohort study, the National Breast Screening Study (NBSS). Women were enrolled in the cohort from 1980 to 1985 to evaluate the efficacy of mammographic screening. Information on usual diet and alcohol intake at enrolment and other epidemiological variables was collected by means of a mailed, self-administered questionnaire. Mortality from breast cancer during follow- up to 31 December, 1993 was ascertained by record linkage to the Canadian Mortality Data Base maintained by Statistics Canada. During the follow-up period of 1980-1993 (average 10.3 years), 223 deaths from breast cancer were identified for this analysis. The hazard ratios for the risk of death from breast cancer increased with intakes of total alcohol of 10-20 g/day (1.039, 1.009-1.071) and > 20 g/day ( 1.063, 1.029-1.098). This increase was contributed largely by the intake of wine, a 15% increase in risk at intakes higher than 10 g/day of alcohol from wine. Alcohol from spirits was associated with a small decrease in risk of death (hazard ratio at 10g/day, 0.945, 0.915-0.976). The effect of alcohol from beer was not significant in the two categories studied. Although our results were statistically significant, the magnitude of the change in risk was small.

Adult↗
PubMed2000

Alcohol consumption and risk of breast cancer: a cohort study.

OBJECTIVES: To study the association between alcohol consumption and breast cancer risk. METHODS: A case-cohort analysis was undertaken within the cohort of 56,837 women who were enrolled in the Canadian National Breast Screening Study (NBSS) and who completed a self-administered dietary questionnaire. (The NBSS is a randomized controlled trial of screening for breast cancer in women aged 40-59 at recruitment.) The cohort was recruited between 1980 and 1985, and during follow-up to the end of 1993 a total of 1469 women in the dietary cohort were diagnosed with biopsy-confirmed incident breast cancer. For comparative purposes a subcohort consisting of a random sample of 5681 women was selected from the full dietary cohort. After exclusions for various reasons the analyses were based on 1336 cases and 5238 noncases. RESULTS: When compared to nondrinkers the adjusted incidence rate ratios (95% confidence intervals) for those consuming > 0 and < or = 10 g of alcohol/day, > 10 and < or = 20 g/day, > 20 and < or = 30 g/day, > 30 and < or = 40 g/day, > 40 and < or = 50 g/day, and > 50 g/day were 1.01 (0.84-1.22), 1.16 (0.91-1.47), 1.27 (0.91-1.78), 0.77 (0.51-1.16), 1.00 (0.57-1.75), and 1.70 (0.97-2.98), respectively; the associated p value for the test for trend was 0.351. Similar findings were obtained when analyses were conducted separately in the screened and control arms of the NBSS, in premenopausal and postmenopausal women, for screen-detected and interval-detected breast cancer, and by levels of other breast cancer risk factors. CONCLUSIONS: The results of this study suggest that alcohol consumption might be associated with increased risk of breast cancer at relatively high levels of intake.

Adult↗
PubMed2000

A cohort study of nutritional factors and endometrial cancer.

To evaluate the role of nutritional factors in the etiology of endometrial cancer, we performed a case-cohort analysis using data from women enrolled in the National Breast Screening Study in Canada from 1980 to 1985. For this analysis, a subcohort was constructed by selecting a 10% random sample from the 56,837 women in the dietary cohort. Cases were the 221 women diagnosed with incident adenocarcinoma of the endometrium during follow-up to December 31, 1993 and ascertained by record linkage to the Canadian Cancer Database. Information on usual diet at enrollment and other epidemiological variables was collected by means of self-administered questionnaires. Hazard ratios were obtained from proportional hazards regression models, with estimation of robust standard errors. We found a strong association of endometrial cancer with body mass index > 25 kg/m2 (hazard ratio 2.72, 95% CI: 2.06-3.50). Endometrial cancer risk was not associated significantly with intakes of total energy, carbohydrates, proteins, total fat and major fatty acids, total dietary fiber and various types of fibers, vitamin C, E and A, folic acid, beta-carotene, lutein, or cryptoxanthin. Some decrease in risk was noted with relatively high intakes of saturated fat, animal fat or lycopene. The associations observed in the study were independent of total energy intake and most non-dietary risk factors. The study suggests that dietary intakes of energy and most major nutrients are not related to the risk of endometrial cancer among Canadian women.

Adult↗