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Biomedical subjects

B Armstrong

Publications and source records attributed to B Armstrong.

At least 19 recordsLinked to original sources
PubMed2006

Interventions for the prevention and management of neck/upper extremity musculoskeletal conditions: a systematic review.

Considered from medical, social or economic perspectives, the cost of musculoskeletal injuries experienced in the workplace is substantial, and there is a need to identify the most efficacious interventions for their effective prevention, management and rehabilitation. Previous reviews have highlighted the limited number of studies that focus on upper extremity intervention programmes. The aim of this study was to evaluate the findings of primary, secondary and/or tertiary intervention studies for neck/upper extremity conditions undertaken between 1999 and 2004 and to compare these results with those of previous reviews. Relevant studies were retrieved through the use of a systematic approach to literature searching and evaluated using a standardised tool. Evidence was then classified according to a "pattern of evidence" approach. Studies were categorised into subgroups depending on the type of intervention: mechanical exposure interventions; production systems/organisational culture interventions and modifier interventions. 31 intervention studies met the inclusion criteria. The findings provided evidence to support the use of some mechanical and modifier interventions as approaches for preventing and managing neck/upper extremity musculoskeletal conditions and fibromyalgia. Evidence to support the benefits of production systems/organisational culture interventions was found to be lacking. This review identified no single-dimensional or multi-dimensional strategy for intervention that was considered effective across occupational settings. There is limited information to support the establishment of evidence-based guidelines applicable to a number of industrial sectors.

Cost-Benefit Analysis↗
PubMed2006

Occupational exposure to power frequency magnetic fields and risk of non-Hodgkin lymphoma.

OBJECTIVES: To investigate the risk of non-Hodgkin lymphoma (NHL) using a job-exposure matrix (JEM) to assess exposure to occupational magnetic fields at the power frequencies of 50/60 Hz. METHODS: The study population consisted of 694 cases of NHL, first diagnosed between 1 January 2000 and 31 August 2001, and 694 controls from two regions in Australia, matched by age, sex and region of residence. A detailed occupational history was given by each subject. Exposure to power frequency magnetic fields was estimated using a population-based JEM which was specifically developed in the United States to assess occupational magnetic field exposure. The cumulative exposure distribution was divided into quartiles and adjusted odds ratios were calculated using the lowest quartile as the referent group. RESULTS: For the total work history, the odds ratio (OR) for workers in the upper quartile of exposure was 1.48 (95% CI 1.02 to 2.16) compared to the referent (p value for trend was 0.006). When the exposure was lagged by 5 years the OR was 1.59 (95% CI 1.07 to 2.36) (p value for trend was 0.003). Adjusting for other occupational exposures did not significantly alter the results. CONCLUSIONS: These findings provide weak support for the hypothesis that occupational exposure to 50/60 Hz magnetic fields increases the risk of NHL.

Adult↗
PubMed2006

Long-term potentiation is associated with changes in synaptic ultrastructure in the rat neocortex.

Long-term potentiation (LTP) in the sensorimotor cortex of freely moving rats has been associated with changes in dendritic morphology and dendritic spine density. The current research examined changes in synaptic number and ultrastructure associated with LTP in this cortical region. LTP was induced over a 1 h period and the animals were sacrificed 2 h after the initial stimulation of the LTP group. Synapses within the terminal area of the apical dendrites from layer III pyramidal neurons were quantified by determining the total number of synapses per neuron, the number of excitatory and inhibitory contacts, number of synapses with different curvature subtypes, number of perforated synapses, and synaptic length. Several changes in synaptic morphology of excitatory synapses were revealed but no overall increase in the number of synapses per neuron was evident. Specifically, the induction of LTP was associated with an increased number of excitatory perforated and concave shaped synapses. Increased numbers of perforated concave synapses were also found to be significantly correlated with the degree of potentiation in the LTP animals. These and previous results suggest similar synaptic changes in both the cortex and hippocampus during the early phases of LTP maintenance and distinct synaptic changes during later phases of LTP maintenance.

Analysis of Variance↗
PubMed2004

Congenital anomaly surveillance in England--ascertainment deficiencies in the national system.

OBJECTIVE: Firstly, to assess the completeness of ascertainment in the National Congenital Anomaly System (NCAS), the basis for congenital anomaly surveillance in England and Wales, and its variation by defect, geographical area, and socioeconomic deprivation. Secondly, to assess the impact of the lack of data on pregnancies terminated because of fetal anomaly. DESIGN: Comparison of the NCAS with four local congenital anomaly registers in England. SETTING: Four regions in England covering some 109,000 annual births. PARTICIPANTS: Cases of congenital anomalies registered in the NCAS (live births and stillbirths) and independently registered in the four local registers (live births, stillbirths, fetal losses from 20 weeks' gestation, and pregnancies terminated after prenatal diagnosis of fetal anomaly). MAIN OUTCOME MEASURE: The ratio of cases identified by the national register to those in local registry files, calculated for different specified anomalies, for whole registry areas, and for hospital catchment areas within registry boundaries. RESULTS: Ascertainment by the NCAS (compared with data from local registers, from which terminations of pregnancy were removed) was 40% (34% for chromosomal anomalies and 42% for non-chromosomal anomalies) and varied markedly by defect, by local register, and by hospital catchment area, but not by area deprivation. When terminations of pregnancy were included in the register data, ascertainment by NCAS was 27% (19% for chromosomal anomalies and 31% for non-chromosomal anomalies), and the geographical variation was of a similar magnitude. CONCLUSION: The surveillance of congenital anomalies in England is currently inadequate because ascertainment to the national register is low and non-uniform and because no data exist on termination of pregnancy resulting from prenatal diagnosis of fetal anomaly.

Abortion, Induced↗
PubMed2004

Ductal carcinoma in situ of the breast, a population-based study of epidemiology and pathology.

In a population-based series of 2109 women with ductal carcinoma in situ (DCIS) diagnosed in 1995-2000 in New South Wales, Australia, incidence increased by an average of 5.5% a year, mostly between 1995 and 1996 and in women 50-69 years of age. This increase paralleled the increases in mammographic screening. BreastScreen NSW, an organised mammographic screening programme, detected 65% of all DCIS. High-grade lesions were 54% of all lesions and were more likely to be 2+ cm in diameter (OR=2.12, 95%CI 1.46-3.14) than low-grade lesions. In all, 40% of DCIS in women younger than 40 years was 2+ cm in diameter compared with 21% in women 40 years and older. Young age, high grade, mixed architecture and multifocality were significant and independent predictors of 2+ cm DCIS.

Adult↗
PubMed2004

Use of the WHO lymphoma classification in a population-based epidemiological study.

BACKGROUND: Non-Hodgkin's lymphoma (NHL) is pathologically diverse. Epidemiological investigations into its increasing incidence and aetiology require accurate subtype classification. PATIENTS AND METHODS: Available pathology reports of 717 cases aged from 20 to 74 years in an Australian, population-based epidemiological study of NHL were reviewed by one anatomical pathologist to assign a World Health Organization (WHO) classification category. High or low confidence was assigned to the diagnosis of NHL, cell phenotype and WHO category and reasons given for low confidence. RESULTS: The most informative biopsy reports were from open tissue biopsy (79% of cases), tissue core biopsy (8%), cytology (4%) and bone marrow (9%); 8% of cases had inadequate biopsies for diagnostic purposes. Immunohistochemistry or flow cytometry reports were available for 96% of cases, gene rearrangement studies for 6% and cytogenetics for 3%. The reviewer assigned high confidence to the diagnosis of NHL in 93% of cases and also the phenotype in 88%. While a WHO classification could be assigned in 91% of cases, confidence was high in only 57.5%; insufficient immunophenotyping was the commonest reason for low confidence. CONCLUSIONS: Expert pathology review of a population-based sample of NHL can provide a WHO classification category for most cases. A high level of confidence in the classification, however, would require review of diagnostic material and additional phenotyping.

Adult↗
PubMed2004

Mortality in a cohort of vermiculite miners exposed to fibrous amphibole in Libby, Montana.

BACKGROUND: Fibrous tremolite is a widespread amphibole asbestiform mineral, airborne fibres of which constitute an environmental hazard in Libby, Montana, northern California, and elsewhere. AIMS: To determine excess risk from lung cancer, mesothelioma, and all-cause mortality in a cohort of men exposed to tremolite, but no other form of asbestos. METHODS: Mortality by certified cause and various measures of exposure to tremolite and related amphibole fibres was assessed in a cohort of 406 vermiculite mineworkers in Libby, Montana, employed before 1963 and followed until 1999. RESULTS: Total deaths were: lung cancer 44 (SMR 2.40), non-malignant respiratory disease (NMRD) 51 (SMR 3.09), all causes 285 (SMR 1.27); included among the total were 12 deaths ascribed to mesothelioma (4.21% of all deaths). Adjusted linear increments in relative risks (per 100 f/ml.y), estimated by Poisson regression, were: lung cancer (0.36, 95% CI 0.03 to 1.20), NMRD (0.38, 95% CI 0.12 to 0.96), and all deaths (0.14, 95% CI 0.05 to 0.26). CONCLUSIONS: The all-cause linear model would imply a 14% increase in mortality for mine workers exposed occupationally to 100 f/ml.y or about 3.2% for a general population exposed for 50 years to an ambient concentration of 0.1 f/ml. Amphibole fibres, tremolite in particular, are likely to be disproportionately responsible for cancer mortality in persons exposed to commercial chrysotile, but to what extent cannot be readily assessed.

Aluminum Silicates↗
PubMed2003

Risk of hypospadias in relation to maternal occupational exposure to potential endocrine disrupting chemicals.

BACKGROUND: Reported rises in the prevalence of hypospadias and other abnormalities of the male reproductive system may be a result of exposure to endocrine disrupting chemicals. AIMS: To analyse the relation between risk of hypospadias and maternal occupation, particularly with regard to exposure to potential endocrine disrupting chemicals (EDCs). METHODS: Data (1980-96) from the National Congenital Anomaly System (NCAS) were used to analyse the proportion of all congenital anomaly cases (n = 35 962) which were notified with hypospadias (n = 3471) by occupational codes (348 individual job titles) and by categories of exposure to potential EDCs from a job exposure matrix. RESULTS: Five individual occupations (of 348) showed nominally statistically significant excesses, none of which had possible or probable exposure to potential EDCs. Odds ratios for "possible" or "probable" compared to "unlikely" exposure to potential EDCs did not show statistically significant increases in any of the EDC categories after adjustment for social class of the mother and father, nor was there evidence of an upward trend in risk with likelihood of exposure. In the 1992-96 time period odds ratios were increased for hairdressers (the largest group exposed to potential EDCs) and for probable exposure to phthalates (of which hairdressers form the largest group) before social class adjustment. CONCLUSIONS: There was little evidence for a relation between risk of hypospadias and maternal occupation or occupational exposure to potential EDCs, but as the exposure classification was necessarily crude, these findings should be interpreted with caution.

Endocrine Glands↗
PubMed2003

Shared care in the management of genital Chlamydia trachomatis infection in primary care.

OBJECTIVES: To investigate the impact of a health adviser in genitourinary medicine as a training and support resource on the management of Chlamydia trachomatis in a large inner city health centre. METHODS: A large, inner city health centre was selected at random for the intervention, with another selected as control. The health adviser offered support and training in the management of C trachomatis to clinical staff in the intervention health centre for 6 months. Data on testing activity were collected over the period of the intervention and during the equivalent period in the previous year. Data on partner notification activities were collected from case notes. RESULTS: The research intervention was effective in increasing C trachomatis testing activity. However, the majority of tests were offered to women over 20 years of age and no increase in the proportion of positive results was observed. CONCLUSIONS: The intervention was effective in increasing C trachomatis testing activity, but did not improve the overall detection rate. Health centre staff accommodated opportunistic testing for C trachomatis into existing healthcare practices, as opposed to introducing new screening systems designed to reach the target population.

Adolescent↗
PubMed2002

A pooled analysis of 10 case-control studies of melanoma and oral contraceptive use.

Data regarding the effects of oral contraceptive use on women's risk of melanoma have been difficult to resolve. We undertook a pooled analysis of all case-control studies of melanoma in women completed as of July 1994 for which electronic data were available on oral contraceptive use along with other melanoma risk factors such as hair colour, sun sensitivity, family history of melanoma and sun exposure. Using the original data from each investigation (a total of 2391 cases and 3199 controls), we combined the study-specific odds ratios and standard errors to obtain a pooled estimate that incorporates inter-study heterogeneity. Overall, we observed no excess risk associated with oral contraceptive use for 1 year or longer compared to never use or use for less than 1 year (pooled odds ratio (pOR)=0.86; 95% CI=0.74-1.01), and there was no evidence of heterogeneity between studies. We found no relation between melanoma incidence and duration of oral contraceptive use, age began, year of use, years since first use or last use, or specifically current oral contraceptive use. In aggregate, our findings do not suggest a major role of oral contraceptive use on women's risk of melanoma.

Adolescent↗
PubMed2002

Chromosomal congenital anomalies and residence near hazardous waste landfill sites.

Previous findings of the EUROHAZCON study showed a 33% increase in risk of non-chromosomal anomalies near hazardous waste landfill sites. Here, we studied 245 cases of chromosomal anomalies and 2412 controls who lived near 23 such sites in Europe. After adjustment for confounding by maternal age and socioeconomic status, we noted a higher risk of chromosomal anomalies in people who lived close to sites (0-3 km) than in those who lived further away (3-7 km; odds ratio 1.41, 95% CI 1.00-1.99). Our results suggest an increase in risk of chromosomal anomalies similar to that found for non-chromosomal anomalies.

Abnormalities, Drug-Induced↗
PubMed2002

Hazard potential ranking of hazardous waste landfill sites and risk of congenital anomalies.

BACKGROUND: A 33% increase in the risk of congenital anomalies has been found among residents near hazardous waste landfill sites in a European collaborative study (EUROHAZCON). AIMS: To develop and evaluate an expert panel scoring method of the hazard potential of EUROHAZCON landfill sites, and to investigate whether sites classified as posing a greater potential hazard are those with a greater risk of congenital anomaly among nearby residents relative to more distant residents. METHODS: A total of 1270 cases of congenital anomaly and 2308 non-malformed control births were selected in 14 study areas around 20 landfill sites. An expert panel of four landfill specialists scored each site in three categories-overall, water, and air hazard-based on readily available, documented data on site characteristics. Tertiles of the average ranking scores defined low, medium, and high hazard sites. Calculation of odds ratios was based on distance of residence from the sites, comparing a 0-3 km "proximate" with a 3-7 km "distant" zone. RESULTS: Agreement between experts measured by intraclass correlation coefficients was 0.50, 0.44, and 0.20 for overall, water, and air hazard before a consensus meeting and 0.60, 0.56, and 0.53 respectively after this meeting. There was no evidence for a trend of increasing odds ratios with increasing overall hazard or air hazard. For non-chromosomal anomalies, odds ratios by water hazard category showed an increasing trend of borderline statistical significance (p = 0.06) from 0.79 in the low hazard category, 1.43 in the medium, to 1.60 in the high water hazard category. CONCLUSIONS: There is little evidence for a relation between risk of congenital anomaly in proximate relative to distant zones and hazard potential of landfill sites as classified by the expert panel, but without external validation of the hazard potential scoring method interpretation is difficult. Potential misclassification of sites may have reduced our ability to detect any true dose-response effect.

Congenital Abnormalities↗
PubMed2001

Pragmatic randomized trial of home visits by a nurse to elderly people with hypertension in Mexico.

BACKGROUND: In Mexico, hypertension is a major cause of disability and death in the elderly, but the most effective way to promote behaviour change in old people is unknown. Low resource interventions that are effective in normal healthcare settings are urgently needed. We report the results of a randomized trial of nurse-provided health and lifestyle advice during home visits to elderly people with hypertension in Mexico City. METHODS: Subjects were 718 people with hypertension aged > or =60 years, who were residents of Mexico City and were registered with the Family Medicine Clinics of the Mexican Institute of Social Security (IMSS). A randomized controlled trial was carried out in which the intervention group was offered nurse visits over 6 months with blood pressure checks and negotiated lifestyle changes. The control group continued to receive usual care. RESULTS: After 6 months, 36.5% of the intervention versus 6.8% of the control group had a blood pressure of <160/90 mmHg. The difference in the mean change in systolic blood pressure was 3.31 mmHg (P = 0.03, 95% CI : 6.32, 0.29) and the same difference in diastolic blood pressure was 3.67 mmHg (P = 0.00, 95% CI : 5.22, 2.12). Weight and sodium excretion fell more in the intervention group, but the difference was not significant. CONCLUSIONS: Nurse home visits are effective in reducing blood pressure in hypertensive patients aged > or =60 years.

Aged↗
PubMed2001

A randomised controlled trial to determine the effectiveness of double Tubigrip in grade 1 and 2 (mild to moderate) ankle sprains.

OBJECTIVE: To compare functional outcome in patients with acute grade 1 or 2 (mild to moderate) lateral ankle sprains randomised to treatment with or without a double tubigrip bandage (DTG). METHODS: 400 patients presenting to the accident and emergency (A&E) departments of a teaching hospital and a district general hospital and diagnosed with grade 1 or 2 lateral ankle sprains were randomised to treatment with or without a DTG bandage. A standardised telephone questionnaire was performed one week after presentation. The main outcome measures were: number of days until walking unaided, number of days off work, whether the injury kept the patient awake at night, whether analgesia was taken. RESULTS: 197 of 400 patients completed follow up. There were no significant differences in terms of age, sex and occupation between the treatment groups. There were no significant differences between those who did and those who did not complete follow up. There was no significant difference between the treatment groups for number of days until walking unaided (95% CI -0.21 to 0.88 days), number of days off work (95% CI -0.70 to 1.02 days) or whether the injury kept the patient awake at night (95% CI -10 to 17%). There was a significant difference between the groups in the use of analgesia (95% CI 10 to 36%); the difference seemed to be that patients treated with DTG required significantly more analgesia. CONCLUSIONS: Treatment of grade 1 and 2 ankle sprins with DTG does not seem to lead to a shorter time to functional recovery and may increase the requirement for analgesia.

Adolescent↗
PubMed2001

Exposures and cancer incidence near oil fields in the Amazon basin of Ecuador.

OBJECTIVES: To examine environmental exposure and incidence and mortality of cancer in the village of San Carlos surrounded by oil fields in the Amazon basin of Ecuador. METHODS: Water samples of the local streams were analyzed for total petroleum hydrocarbons (TPHs). A preliminary list of potential cancer cases from 1989 to 1998 was prepared. Cases were compared with expected numbers of cancer morbidity and mortality registrations from a Quito reference population. RESULTS: Water analysis showed severe exposure to TPHs by the residents. Ten patients with cancer were diagnosed while resident in the village of San Carlos. An overall excess for all types of cancer was found in the male population (8 observed v 3.5 expected) with a risk 2.26 times higher than expected (95% confidence interval (95% CI) 0.97 to 4.46). There was an overall excess of deaths for all types of cancer (6 v 1.6 expected) among the male population 3.6 times higher than the reference population (95% CI 1.31 to 7.81). CONCLUSIONS: The observed excess of cancer might be associated with the pollution of the environment by toxic contaminants coming from the oil production.

Adult↗