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Biomedical subjects

A B Miller

Publications and source records attributed to A B Miller.

At least 109 records · Page 6Linked to original sources
PubMed1997

Risk of congenital anomalies in children of parents occupationally exposed to low level ionising radiation.

OBJECTIVES: To evaluate the risk of having a child with a congenital anomaly in relation to occupational exposure to low level ionising radiation in the pre-conception period. METHODS: A case-control study based on the Canadian congenital anomalies registry used record linkage techniques to identify congenital anomalies among male and female workers in Canada's largest electric company. Cases were defined as parents of a child with a congenital anomaly born between April 1979 and December 1986 who had a congenital anomaly diagnosed within the first year of life. Controls were an individually matched sample of parents of a liveborn child without an anomaly. Risk of congenital anomaly was assessed in relation to parental exposure to ionising radiation acquired through work within a nuclear generating station of an electric power company. Exposure was assessed according to employment, whether or not the worker was monitored for radiation exposure, and quantitative estimates of radiation dose. RESULTS: Employment within the electric power industry was not associated with an increased risk of congenital anomalies in the offspring of mothers or fathers. Risk estimates for workers monitored (those who are likely to be exposed to ionising radiation) were 1.75 (95% confidence interval (95% CI) 0.86 to 3.55) for mothers and 0.84 (95% CI 0.68 to 1.05) for fathers. Exposure for fathers before conception, defined cumulatively and for six months before conception, was not associated with increased risk of anomalies in their offspring. There were no significant increases in risk found between type of anomaly and any measure of exposure, although the statistical power in these groups was limited. The study had insufficient numbers to evaluate the effects of ionising radiation in mothers as only three mothers had recorded doses > 0 mSv. CONCLUSIONS: Overall, workers in a nuclear power industry, and specifically those exposed before conception to low levels of ionising radiation, do not appear to be at an increased risk of having a liveborn child with a congenital anomaly.

Canada↗
PubMed1997

Adults with mental retardation as supports to their parents: effects on parental caregiving appraisal.

This study was conducted to determine whether support provided to caregivers by their adult children with mental retardation would influence caregiving appraisals. We also examined how severity of disability of the adult child, personal and social resources of the caregiver, and amount of caregiver assistance to the adult with mental retardation influenced caregiving appraisals. Using surveys and interviews we collected information from 80 primary caregivers on caregiving burden and satisfaction and six predictors of burden and satisfaction. Findings indicate that greater support from the adult child to the caregiver resulted in greater satisfaction and less burden. Adaptive and maladaptive behaviors and caregiving assistance all predicted caregiving satisfaction but only maladaptive behaviors predicted caregiving burden.

Adult↗
PubMed1997

Physical performance of elite New Zealand Olympic class sailors.

OBJECTIVE: The purpose of this study was to compare the physical performance of elite New Zealand and other nations olympic class sailors and to undertake an initial examination of the relation between physical and sailing performance. EXPERIMENTAL DESIGN: A comparative study. SETTING: Healthy elite national level olympic class sailors were examined. PARTICIPANTS: Thirty-one elite New Zealand Olympic sailing squad team members and 108 Olympic team sailors from ten other nations. INTERVENTIONS: The data for the two groups of subjects was compared using unpaired "t"-tests. A qualitative analysis was used to examine the relation between physical and sailing performance. MEASURES: Measurements included age, body mass, muscular strength endurance (as assessed by the maximum number of push-ups, pull-ups and sit-ups that could be performed) and serobic power (as assessed by the time taken to cover 2500 m and the distance completed in 12 minutes in a maximal effort rowing ergometer test). Sailing performance was assessed by national coach ranking of each New Zealand sailor. RESULTS: On average the New Zealanders were younger and lighter than the sailors from the other nations. They tended to have greater shoulder/arm strength endurance as reflected in their performance for push-ups and pull-ups, but a lesser ability in their sit-up performance. They also tended to be aerobically fitter. There were clear and logical differences between body mass and both class of vessel and the position of the sailor i.c. crew or helmsman. Lighter sailors sailed lighter craft whilst heavier sailors sailed the heavier craft. Crew members were generally heavier than helmsmen. Age appeared to be related to sailing performance. CONCLUSIONS: Elite New Zealand Olympic class sailors tend to be younger, lighter, stronger and aerobically fitter than elite sailors from other nations. Age appeared to be related to on-water sailing performance.

Adolescent↗
PubMed1997

Knowledge and reported use of sport science by elite New Zealand Olympic class sailors.

OBJECTIVE: This study enquired about the knowledge and reported use of sport science in elite Olympic class sailors. EXPERIMENTAL DESIGN: The sailors responded to a simple questionnaire. SETTING: The questionnaire was administered as part of an introductory seminar on sport science during a training camp. PARTICIPANTS: The participants were 28 (22 male, 6 female) elite New Zealand Olympic class sailors. INTERVENTIONS: None. MEASURES: The questionnaire asked whether or not they used a training race diary, enquired about their current and past injuries and their knowledge and use of sport science in the areas of nutrition, psychology and physical training. RESULTS: Only ten (36%) of the sailors kept a training/race diary. Whilst only four (14%) had a current injury, sixteen (57%) reported an injury in the previous three years. The injuries were in the lower back (45%), knee (22%), shoulder (18%), and arm (15%). Although nineteen (68%) of the sailors had experienced dehydration during racing, the average volume of fluid reported to be taken on a four hour sail was only 0.9 litre, of which only an average of 0.7 litres (77%) was reported to be drunk. All the sailors reported being sometimes (46%) to very often (3%) anxious before races and sometimes (43%) to always (7%) being frustrated with their own mistakes. Only one sailor reported never having negative thoughts whilst fifteen (53%) reported having them sometimes, and seven (25%) often or very often. Twenty-four (86%) of the sailors reported that they sometimes had a loss of concentration near the end of the race. Whilst eighteen (64%) reported practising relaxation and seventeen (61%) reported practising visualisation as a mental skill, only five (18%) practised progressive mental relaxation, two (7%) practised meditation and none practised yoga. Seventeen (61%) undertook strength/circuit training, ten (36%) flexibility and twenty-one (75%) off water aerobic training. Twenty-four (86%) reported undertaking on-water aerobic training. CONCLUSIONS: The results indicate that there is considerable scope for improvement in the knowledge and use of sports science amongst elite New Zealand Olympic class sailors.

Adolescent↗
PubMed1996

Effect of amlodipine on morbidity and mortality in severe chronic heart failure. Prospective Randomized Amlodipine Survival Evaluation Study Group.

BACKGROUND: Previous studies have shown that calcium-channel blockers increase morbidity and mortality in patients with chronic heart failure. We studied the effect of a new calcium-channel blocker, amlodipine, in patients with severe chronic heart failure. METHODS: We randomly assigned 1153 patients with severe chronic heart failure and ejection fractions of less than 30 percent to double-blind treatment with either placebo (582 patients) or amlodipine (571 patients) for 6 to 33 months, while their usual therapy was continued. The randomization was stratified on the basis of whether patients had ischemic or nonischemic causes of heart failure. The primary end point of the study was death from any cause and hospitalization for major cardiovascular events. RESULTS: Primary end points were reached in 42 percent of the placebo group and 39 percent of the amlodipine group, representing a 9 percent reduction in the combined risk of fatal and nonfatal events with amlodipine (95 percent confidence interval, 24 percent reduction to 10 percent increase; P=0.31). A total of 38 percent of the patients in the placebo group died, as compared with 33 percent of those in the amlodipine group, representing a 16 percent reduction in the risk of death with amlodipine (95 percent confidence interval, 31 percent reduction to 2 percent increase; P=0.07). Among patients with ischemic heart disease, there was no difference between the amlodipine and placebo groups in the occurrence of either end point. In contrast, among patients with nonischemic cardiomyopathy, amlodipine reduced the combined risk of fatal and nonfatal events by 31 percent (P=0.04) and decreased the risk of death by 46 percent (P<0.001). CONCLUSIONS: Amlodipine did not increase cardiovascular morbidity or mortality in patients with severe heart failure. The possibility that amlodipine prolongs survival in patients with nonischemic dilated cardiomyopathy requires further study.

Aged↗
PubMed1996

Leukemia following occupational exposure to 60-Hz electric and magnetic fields among Ontario electric utility workers.

In a nested case-control study of 1,484 cancer cases and 2,179 matched controls from a cohort of 31,543 Ontario Hydro male employees, the authors evaluated associations of cancer risk with electric field exposure and reevaluated the previously reported findings for magnetic fields. Pensioners were followed from January 1, 1970, and active workers (including those who left the corporation) from January 1, 1973, with both groups followed through December 31, 1988. Exposures to electric and magnetic fields and to potential occupational confounders were estimated through job exposure matrices. Odds ratios were elevated for hematopoietic malignancies with cumulative electric field exposure. After adjustment, the odds ratio for leukemia in the upper tertile was 4.45 (95% confidence interval (CI) 1.01-19.7). Odds ratios were also elevated for acute nonlymphoid leukemia, acute myeloid leukemia, and chronic lymphoid leukemia. For cumulative magnetic field exposure, there were similar elevations that fell with adjustment. Evaluation of the combined effect of electric and magnetic fields for leukemia showed significant elevations of risk for high exposure to both, with a dose-response relation for increasing exposure to electric fields and an inconsistent effect for magnetic fields. There was some evidence of a nonsignificant association for brain cancer and benign brain tumors with magnetic fields. For lung cancer, the odds ratio for high exposure to electric and magnetic fields was 1.84 (95% CI 0.69-4.94).

Adult↗
PubMed1996

Cigarette smoking and pancreas cancer: a case control study of the search programme of the IARC.

A multi-centre case-control study of pancreas cancer, designed to be population-based, to use a random sample of local populations as controls and to use a common protocol and core questionnaire, was conducted as the first study of the SEARCH programme of the International Agency for Research on Cancer. "Ever-smokers" were found to be at increased risk for pancreas cancer compared with "never-smokers" consistently in all strata of gender, response status and centre. Risk of pancreas cancer was found to increase with increasing lifetime consumption of cigarettes, the relative risk rising to 2.70 (95% C.I. 1.95 to 3.74) in the highest intake category. The overall trend in risk was highly significant and the association was found consistently in each stratum of gender, response status and centre. Fifteen years had to pass from quitting cigarette smoking until the risk fell to a level compatible with that in never-smokers among the heaviest group of smokers; among the 2 lowest tertiles this happened within 5 years. Further, reported smoking habits more than 15 years before diagnosis appeared to have no influence on pancreas-cancer risk, irrespective of amount smoked. The results are consistent with a causal role for cigarette smoking in the aetiology of pancreas cancer and illustrate that ceasing to smoke cigarettes can lead to reductions in the elevated risk of pancreas cancer produced by this habit.

Case-Control Studies↗
PubMed1996

Interactions between geminivirus replication proteins.

Geminiviruses are small DNA viruses that replicate in the nuclei of infected plant cells. The closely related geminiviruses tomato golden mosaic virus and bean golden mosaic virus each encode a protein, AL1, that catalyzes the initiation of rolling-circle replication. Both viruses also specify a second replication protein, AL3, that greatly enhances the level of viral DNA accumulation. Using recombinant proteins produced in a baculovirus expression system, we showed that AL1 copurifies with a protein fusion of glutathione S-transferase (GST) and AL1, independent of the GST domain. Similarly, authentic AL3 cofractionates with a GST-AL3 fusion protein. These results demonstrated that both AL1 and AL3 form oligomers. Immunoprecipitation of protein extracts from insect cells expressing both AL1 and AL3 showed that the two proteins also complex with each other. None of the protein interactions displayed virus specificity; the tomato and bean golden mosaic virus proteins complexed with each other. The addition of heterologous replication proteins had no effect on the efficiency of geminivirus replication in transient-replication assays, suggesting that heteroprotein complexes might be functional. The significance of these protein interactions is discussed with respect to geminivirus replication in plant cells.

Geminiviridae↗
PubMed1996

Cancer of the respiratory system in Circumpolar Inuit.

Cancer incidence of the nasal cavities in Inuit men are high (ASR=3.0 1984-1988), and higher than seen in Denmark, Connecticut (USA) and Canada. Lung cancer incidence is among the highest in the world, for both men and women, and larynx cancer among the lowest. The smoking pattern among Inuit, possibly combined with co-factors related to environment and diet, are believed to be the relevant causal factors.

Adolescent↗
PubMed1996

Breast cancer in Circumpolar Inuit 1969-1988.

Breast cancer was studied over a 20-year period in Inuit populations in the Circumpolar region. A total of 193 breast cancers were observed in women. The incidence increased from 28.2 per 100 000 in 1969-1973 to 34.3 per 100 000 in 1984-1988. However, the incidence is low, about half what could be expected based on the rates in Denmark, Canada and Connecticut (USA). The low incidence could be explained by the Inuit diet and other lifestyle factors. These benefits should be preserved, in particular in the young, to maintain a low breast cancer incidence.

Adolescent↗
PubMed1996

Cancers of skin, bone, connective tissues, brain, eye, thyroid and other specified and unspecified sites in Inuit.

Low rates of skin cancer, both melanoma and non-melanoma, were observed in Inuit after 20 years of observation. Tumours of the brain and central nervous system, of the thyroid, bone and connective tissues and other specified sites occurred with rates similar to those in comparison populations in Denmark, Connecticut and Canada. These findings support that neither UV and ionizing radiation from nuclear fall-out, nor pollution of herbicides and pesticides in the Arctic area have yet had any noticeable impact on cancer risk. However, unspecified and secondary neoplasms constitute 7-8% of the total Circumpolar cancer incidence and the pattern of rare cancers must be interpreted with caution. Increased diagnostic efforts with a higher precision in the future are warranted.

Adolescent↗
PubMed1996

Guidelines from the consumer: improving consumer involvement in research and training for persons with mental retardation.

Consumer involvement of individuals with mental retardation in research and training was assessed. Twenty-two subjects with experience in research and/or training were interviewed to determine how professionals can encourage meaningful participation of persons with mental retardation in research and training activities. Results suggest that persons with mental retardation have participated in various roles in research and training but that there are many barriers to meaningful consumer involvement that have not been adequately addressed. Guidelines for professionals to foster meaningful consumer involvement in research and training activities were provided.

Adult↗
PubMed1996

Risk factors for breast cancer mortality among the National Breast Screening Study of Canada participants.

We studied the relationship between risk factor information and breast cancer mortality by means of a case control study, nested within the population of the National Breast Screening Study of Canada (NBSS). The characteristics of women aged 40-59 years, identified at the initial screen, who subsequently died of breast cancer up to 7 years from the initial screen, were compared with those of controls drawn from the same population. Among the factors evaluated in this study, number of live births and presence of symptoms in the breast revealed on direct questioning were found to be significantly related to breast cancer mortality. The results suggest a decrease in risk of dying of breast cancer associated with one or more live births (OR: 0.79, 95% CI: 0.68, 0.93), and an increase in risk of dying of breast cancer associated with symptoms in the breast revealed on direct questioning at the initial screen (OR: 2.01, 95% CI: 1.20, 3.37).

Adult↗
PubMed1996

Awareness, action, and collaboration: how the self-advocacy movement is empowering for persons with developmental disabilities.

In response to stigmatization and lack of opportunities in the United States, a self-advocacy movement by and for persons with developmental disabilities has grown. In parallel, in the empowerment literature in the social sciences, authors have sought to conceptualize the process of becoming empowered. There is little in the empowerment literature that fosters an understanding of the self-advocacy movement. In this paper, four relevant principles of empowerment (which concern gaining awareness of societal discrimination, individual rights, and personal strengths; taking action through participation in community organizations; and working collaboratively with supportive advisors) were considered. Through awareness, action, and collaborative support, self-advocates can transform themselves from marginalized targets of discrimination to respected citizens.

Awareness↗