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Biomedical subjects

M Robson

Publications and source records attributed to M Robson.

At least 19 recordsLinked to original sources

Concentration of organochlorine in egg yolk and reproductive success of Egretta garzetta (Linnaeus, 1758) at Wat Tan-en non-hunting area, Phra Nakhorn Si Ayuthaya Province, Thailand.

Contaminant analyses in animal eggs have illustrated the benefit of wildlife as indicators of xenobiotic contamination in natural habitats. In 2002, concentrations of 16 organochlorine insecticides were measured in egg yolk and the reproductive success of the little egret, Egretta garzetta, was studied in a population at Wat Tan-en non-hunting area Bang Pahan District, Phra Nakhorn Si Ayuthaya Province, Thailand. Only 4,4'-dichloro diphenylethane (4,4'-DDE) was detected in the yolk of all samples (n=12) at the concentrations ranging from 33.4 to 116.0 ng/gwetwt. Mean eggshell thickness (n=24) was 0.261+/-0.005 mm. Relationships between the concentrations of 4,4'-DDE and eggshell thickness as well as the reproductive success at all stages were not found (P>0.05). Rather, major factors potentially influencing the decline of reproductive success observed during the field study may include strong wind, predators, intraspecific and interspecific competitions.

Animals↗

Should every unit have a 24-hour transvaginal ultrasound available?

The purpose of this debate is to argue the merits of whether the availability of 24-hour transvaginal ultrasound service in every unit will help predict and, subsequently, prevent preterm birth. Any new test introduced will need to fulfil certain criteria. It must be acceptable in terms of risk, cost and patient convenience. It must be an improvement over existing alternatives, and it must aid clinicians to improve care. While the 24-hour availability of transvaginal ultrasound to every maternity unit may be useful to research and teaching, there is, as yet, little evidence that a 24-hour transvaginal ultrasound service improves perinatal and maternal morbidity and mortality. Results from our own centre suggest that experienced clinicians can make an acceptable diagnosis of spontaneous preterm labour (PTL) using only history and digital examination. Based on these findings, the availability of 24-hour vaginal ultrasound in every unit cannot be justified for the diagnosis of spontaneous PTL.

Female↗

A note on competing risks in survival data analysis.

Survival analysis encompasses investigation of time to event data. In most clinical studies, estimating the cumulative incidence function (or the probability of experiencing an event by a given time) is of primary interest. When the data consist of patients who experience an event and censored individuals, a nonparametric estimate of the cumulative incidence can be obtained using the Kaplan-Meier method. Under this approach, the censoring mechanism is assumed to be noninformative. In other words, the survival time of an individual (or the time at which a subject experiences an event) is assumed to be independent of a mechanism that would cause the patient to be censored. Often times, a patient may experience an event other than the one of interest which alters the probability of experiencing the event of interest. Such events are known as competing risk events. In this setting, it would often be of interest to calculate the cumulative incidence of a specific event of interest. Any subject who does not experience the event of interest can be treated as censored. However, a patient experiencing a competing risk event is censored in an informative manner. Hence, the Kaplan-Meier estimation procedure may not be directly applicable. The cumulative incidence function for an event of interest must be calculated by appropriately accounting for the presence of competing risk events. In this paper, we illustrate nonparametric estimation of the cumulative incidence function for an event of interest in the presence of competing risk events using two published data sets. We compare the resulting estimates with those obtained using the Kaplan-Meier approach to demonstrate the importance of appropriately estimating the cumulative incidence of an event of interest in the presence of competing risk events.

Humans↗

Dehalogenation of chlorinated aromatic compounds using a hybrid bioinorganic catalyst on cells of Desulfovibrio desulfuricans.

A novel bioinorganic catalyst was obtained via reduction of Pd(II) to Pd0 on to the surface of cells of Desulfovibrio desulfuricans at the expense of H2. Palladised biomass, supplied with formate or H2 as an electron donor, catalysed the dehalogenation of 2-chlorophenol and polychlorinated biphenyls. In the example of 2,3,4,5-tetrachlorobiphenyl, the bioinorganic catalyst promoted a rate of chloride release of 9.33 +/- 0.17 nmol min(-1) mg (-1) and only approximately 5% of this value was obtained using chemically reduced or commercially available Pd0. In the case of 2,2',4,4',6,6'-hexachlorobiphenyl the rate was more than four orders of magnitude faster than the degradation reported using a sulfidogenic culture. Negligible chloride release occurred from any of the chloroaromatic compounds using biomass alone, or from palladised biomass challenged with hexane carrier solvent only. Analysis of the spent solution showed that in addition to catalysis of reductive dehalogenation the new material was able to remove very effectively the organic residua, with neither any PCB nor any breakdown products identifiable by GC/MS.

Biodegradation, Environmental↗

Access to the GDS.

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General Practice, Dental↗

Exploring health, safety and environment in central and Eastern Europe: an introduction to the European Centre for Occupational Health, Safety and the Environment (ECOHSE).

This article traces the development of the European Centre for Occupational Health, Safety and the Environment (ECOHSE) at the University of Glasgow. ECOHSE recently has been designated a Thematic Network by the European Union which is providing administrative support through 2004. The de facto de-regulation that accompanied emergent capitalism in Eastern Europe created opportunities for exploitation of the work force. Voluntary efforts of a loose network of occupational and environmental health academics led to a series of yearly conferences to discuss these problems and the lack of research about them. Then, in 1999, a more formal organization was established at Glasgow to pursue continuity and funding. The first occupational and environmental health conference under ECOHSE was held last year in Lithuania, and selected presentations of that meeting are offered in this journal. A second ECOHSE conference will be held this fall in Romania.

Journal Article↗

Field conditions for agricultural workers in the El Paso, Texas region.

Agricultural workers labor long hours under difficult conditions in many of the nations fields and orchards. Agricultural workers are primarily minority populations, the most dominant group being Hispanic/Latino. The Rural Coalition and the Environmental and Occupational Health Sciences Institute were funded under the National Institute of Environmental Health Sciences (NIEHS) Environmental Justice Program, to investigate health and environmental issues that impact agricultural workers along the Texas-Mexican border area. A Spanish-language field conditions survey was developed and distributed to the workers entering the Sin Fronteras Organizing Project in El Paso, Texas. There were 841 valid surveys collected and analyzed for the calendar year 1998. Workers age mean was 51, with 18.6 years of work experience in agriculture. In the time period surveyed, workers labored for 7.2 hours per day. The primary crop in which they worked were chilies. Of particular concern were issues concerning food, water, and hygiene. Almost all workers stated they had access to fresh drinking water (97 percent), 20 percent did not have access to food, and 30 percent were offered alcohol for purchase. Almost one-third of the workers did not have water available for hand washing in the field. Only 8 percent of the workers reported pesticides used in the fields in which they were working; this number is lower and may be a reflection of the improved training and caution taken by the workers. Clearly additional research in the area of field conditions and the impact and enforcement of state and federal regulation needs to be carried out.

Journal Article↗

Tamoxifen and risk of contralateral breast cancer in BRCA1 and BRCA2 mutation carriers: a case-control study. Hereditary Breast Cancer Clinical Study Group.

BACKGROUND: Women with a mutation in BRCA1 or BRCA2 have a high risk of developing breast cancer and of contralateral cancer after the initial diagnosis of breast cancer. Tamoxifen protects against contralateral breast cancer in the general population, but whether it protects against contralateral breast cancer in BRCA1 or BRCA2 mutation carriers is not known. METHODS: We compared 209 women with bilateral breast cancer and BRCA1 or BRCA2 mutation (bilateral-disease cases), with 384 women with unilateral disease and BRCA1 or BRCA2 mutation (controls) in a matched case-control study. Age and age at diagnosis of breast cancer (range 24-74 years) were much the same in bilateral-disease cases and controls, and both groups had been followed up for the same time for a second primary breast cancer. History of tamoxifen use for first breast cancer was obtained by interview, or by self-administered questionnaire. FINDINGS: The multivariate odds ratio for contralateral breast cancer associated with tamoxifen use was 0.50 (95% CI 0.28-0.89). Tamoxifen protected against contralateral breast cancer for carriers of BRCA1 mutations (odds ratio 0.38, 95% CI 0.19-0.74) and for those with BRCA2 mutations (0.63, 0.20-1.50). In women who used tamoxifen for 2-4 years, the risk of contralateral breast cancer was reduced by 75%. A reduction in risk of contralateral cancer was also seen with oophorectomy (0.42, 0.22-0.83) and with chemotherapy (0-40, 0.26-0.60). INTERPRETATION: Tamoxifen use reduces the risk of contralateral breast cancer in women with pathogenic mutations in the BRCA1 or BRCA2 gene. The protective effect of tamoxifen seems independent of that of oophorectomy.

Adult↗

Are BRCA1- and BRCA2-associated breast cancers different? Prognosis of BRCA1-associated breast cancer.

PURPOSE: To review the available literature regarding the outcome of breast cancer arising in the setting of a germline BRCA1 mutation. METHODS: Reports of relevant studies obtained from a search of MEDLINE and studies referenced in those reports were reviewed. In addition, data from a previously published study of breast conservation therapy among women of Ashkenazi descent were reanalyzed to discern the effect of germline BRCA1 status. RESULTS: Although BRCA1-associated breast cancers have been associated repeatedly with poor prognostic features, studies that examine the impact of germline BRCA1 status on outcome have not consistently shown an adverse effect of BRCA1 mutations. In part, this may result from methodologic limitations of earlier trials. Recent studies that examine relatively unselected groups of Ashkenazi women have indicated a negative prognostic effect of specific BRCA1 mutations. It remains to be determined, however, whether BRCA1 status is an independent prognostic factor and whether the findings can be generalized to other mutations. CONCLUSION: BRCA1-associated breast cancers present with histopathologic features that seem to confer an adverse prognosis, at least in certain subgroups. However, it is not clear whether BRCA1 status has an independent effect on outcome. Until further data become available, treatment for BRCA1-associated breast cancer should be determined by the same factors that influence therapy of nonhereditary disease.

BRCA2 Protein↗

Epidural analgesia need not increase operative delivery rates.

OBJECTIVE: We sought to examine the relationship between epidural analgesia and cesarean and instrumental vaginal delivery rates. STUDY DESIGN: This is a retrospective analysis of the first 1000 nulliparous pregnancies in women with a cephalic presentation in spontaneous labor at term in each of 3 different years, over which the epidural rate increased from 10% to 57%. RESULTS: Cesarean and instrumental vaginal delivery rates were similar in all 3 years. Demographic characteristics remained unchanged or altered in a manner that has previously been associated with an increase in intervention. Electronic fetal monitoring and first-stage oxytocin use remained unchanged, but oxytocin use in the second stage increased considerably. CONCLUSIONS: Increased use of epidural analgesia had no effect on cesarean delivery rates. Although randomized trials have suggested that it increases instrumental vaginal delivery rates, this might be overcome by active management of labor or judicious use of oxytocin in the second stage.

Adult↗