Styrene emissions from the spray-up and vacuum injection processes--a quantitative comparison

Styrene emissions were studied during manufacturing of two identical glass-fiber reinforced plastic boats by two different manufacturing methods. The manufacturing methods were spray-up, which is an open method, and vacuum injection, which is a closed method. Changing the manufacturing process from an open method to a closed method decreased the styrene evaporation dramatically in this particular case. By using vacuum injection, the styrene emission during the laminate application was reduced by 98% compared with the styrene emission during laminate application by spray-up. Gel coat application by spraying will remain a major source for styrene emissions. The greatest environmental benefit is achieved with closed manufacturing methods when products without gel coat are made. The whole manufacturing process can then be performed in a closed system virtually free from emissions.     

Discounting and clinical decision making: physicians,patients, the general public,and the management of asymptomatic abdominal aortic aneurysms

Clinical decisions often entail in intertemporal trade-off. Moreover, they often involve physicians of different specialities. In an experiment dealing with the management of small asymptomatic abdominal aortic aneurysms (a clinically relevant problem) we find that specialists in internal medicine exhibit higher implicit discount rates than vascular surgeons, general practitioners, and actual and prospective patients. Several personal characteristics expected to be directly related to pure time-preference and risk aversion (gender, smoking habits, age, place of employment) have the hypothesised effects. Additionally, financial incentives appear to affect the estimated implicit discount rates of physicians, but are unlikely to have caused the inter-group differences. Differences in discount rates could lead to variations in clinical practice, which may conflict with equality of treatment or equal access to health care.     

The interaction of education and cumulative lead exposure on the Mini-Mental State Examination

The effect of lead exposure on neurobehavioral performance is modified by age. Whether educational achievement can serve as an effect modifier on the lead-cognitive performance relationship is examined. The Mini-Mental State Examination (MMSE) and the reading section of the Wide Range Achievement Test-Revised (WRAT-R), a measure of educational achievement, were administered to 256 lead smelter workers. The workers had a mean (standard deviation) age of 41 (7.9) years, education of 10 (2.8) years, employment duration of 17 (8.1) years, current blood lead of 28 (8.8) micrograms/dL, and working lifetime integrated blood lead index (IBL) of 725 (434) micrograms-yr/dL. The median (range) MMSE score was 29 (19 to 30). Multiple linear regression assessed the contribution of age, WRAT-R, education, alcohol intake, cigarette use, IBL, and IBL x WRAT-R on MMSE performance. A significant IBL x WRAT-R interaction examined by stratification found a significant dose-effect relationship between IBL and MMSE, but only in the 78 workers with a WRAT-R reading grade level below 6 years. Workers with higher educational achievement compensated for the effect of lead on cognitive performance.     

The pattern of estradiol and progesterone differs in serum and tissue of benign and malignant ovarian tumors

Epidemiological studies have indicated a relationship between gonadal steroid hormones and ovarian cancer. A production of both estradiol and progesterone by ovarian cancers has been demonstrated. The local steroid concentrations and the putative relation to histopathological and clinical condition were investigated herein. Ovarian tissue, ovarian tumor cyst fluid, ovarian vein samples and peripheral serum concentrations of estradiol and progesterone in pre- and post-menopausal women, subdivided into groups with normal ovaries, benign, borderline and malignant ovarian tumors, were quantitatively assessed. Both ovarian tissue concentrations of estradiol and progesterone were more than 100-fold higher than in serum. Based on differences in concentrations between different ovarian tumor groups, the data is not coherent with the previously suggested increased production of estradiol and progesterone in ovarian cancer tissue, since post-menopausal women with ovarian cancer presented lower median tissue hormone levels, most pronounced between malignant and benign tumors; median (25 and 75 percentile) estradiol; 9.40 (6.67-15.50) vs 16.44 (12.49-23.20), p=0.02 and progesterone; 308 (240-575) vs 957 (553-1143) pmol/g wet weight, p<0.01, n=81. Lower concentrations of estradiol, but not progesterone, were found in ovarian cancer tissue, ovarian cyst fluid and peripheral serum in patients with FIGO stages 3 and 4 than in stages 1 and 2. The novel finding of a large ovarian tissue to serum difference of both estradiol and progesterone indicates an important role of ovarian tissue concentrations in tumor biology and raises the question of adequate doses of anti-hormonal therapy in women with ovarian cancer.     

Microglia activation and cell death in response to diethyl-dithiocarbamate acute administration

An increasing body of evidence suggests a role for activated microglia in the pathogenesis of neurodegenerative disorders. Hence, it would be useful to have a better understanding of the significance of microglial activation for neuronal damage. Unfortunately, most models of microglial activation use invasive or long-lasting insults, which make it difficult to evaluate the role played by microglia. We have instead developed a model for microglial activation by using brief exposure to the widely available neurotoxin diethyl-dithiocarbamate (DDTC). Despite evidence for the neurotoxic nature of this substance, microglia involvement has not been hitherto investigated. After acute i.p. administration of DDTC at two different doses, microglia were already activated in selected areas of the rat brain (hippocampal dentate gyrus, entorhinal-pyriform cortex and hypothalamus) after 1 hour, reaching a peak at 3-6 hours and subsided within 6-48 hours, depending on the brain region. Microglia activation was associated with interleukin-1 beta immunopositivity between 3 and 6 hours and with up-regulation of major histocompatibility complex class II expression between 24 and 48 hours. No significant changes in astrocyte immunostaining were detected between 6 hours and 6 days. The TUNEL procedure revealed the death of a limited number of cells in the above-mentioned structures that peaked at 6h and then declined rapidly. Cell death was detected in sites with major, minor, or no microglial activation, indicating that these two events can occur concomitantly or independently. The study shows that the administration of DDTC provides a useful model for studying the implications of region-specific reactivity of microglia and its differential interaction with neuronal damage.     

Memory for perceived and imagined pictures--an event-related potential study

Event-related potentials (ERPs) and behavioural measures were used to investigate recognition memory and source-monitoring judgements about previously perceived and imagined pictures. At study, word labels of common objects were presented. Half of these were followed by a corresponding picture and the other half by an empty frame, signalling to the participants to mentally visualise an image. At test, participants in a source-monitoring task made a three-way discrimination between new words and words corresponding to previously perceived and imagined pictures. Participants in an old/new-recognition task indicated whether test words were previously presented or not. In both tasks, correctly identified old items elicited more positive-going ERPs than correctly judged new items. This widely distributed old/new effect was found to have an earlier onset and to be of a greater magnitude for imagined than for perceived items. Task (source versus item-memory) affected the old/new effects over prefrontal areas and the reaction times to remembered old items. The present findings are consistent with the view that a greater amount, or a different type, of information is necessary for accurate source-memory judgements than for correct recognition, and moreover, that different types of source-specifying information revive at different rates. In addition, the results add weight to the view that the late widespread ERP-old/new effect is sensitive to the quality or the amount of information retrieved from memory.     

Distribution of leucine-enkephalin in bone and joint tissues

The distribution and concentration of leu-enkephalin in periosteum, cortical bone, bone marrow and synovial membrane of normal rats were analysed. Periosteum, cortical bone and bone marrow of the rat femurs were collected as well as the ankles. The distribution of leu-enkephalin was analysed by immunoelectron microscopy and the concentration of leu-enkephalin was measured with radioimmunoassay. Immunoelectron microscopy showed that leu-enkephalin is abundant in monocytes of bone marrow, nerve fibers and endothelial cells in the periosteum and also in macrophage-like-cells of the synovial membrane. The concentration of leu-enkephalin measured by RIA showed highest concentration in bone marrow followed by periosteum and cortical bone. The study supports that leu-enkephalin is present and can be quantified in different compartments of bone and joint tissues suggesting that leu-enkephalin may be involved in the physiological regulation of nociception and immunoregulation.     

Behaviour of the 2.1-mm (14 G) automated biopsy needle in phantoms

PURPOSE: To study the behaviour of the 2.1-mm (14 G) core biopsy needle in targets of different consistencies and to correlate the needle behaviour to lengths of the samples. MATERIAL AND METHODS: A series of butter blocks at temperatures of -5 degrees C, -2 degrees C, +1 degrees C, +4 degrees C, +7 degrees C, +10 degrees C, +13 degrees C, +16 degrees C and +19 degrees C simulating lesions of different hardness in human breast, were passed with needles (3 passes at each temperature). Inner needle behaviour was studied both with and without outer cannula effect. RESULTS: At +4 degrees C to +13 degrees C the needle had a curved course, deviated to the side of its tip. At +4 degrees C, the needle was most deviated (range 4, 8, 10 degrees ) and the samples were largest (8, 12, 12 mm). At -5 degrees C to +1 degrees C the needle was bent, the cannula was not triggered and no sample was obtained. At +16 degrees C and +19 degrees C the needle had a straight course and the length of the sample was decreasing. CONCLUSION: Behaviour of the inner needle as well as the cannula depends on the hardness of the target. Targets of intermediate hardness yield adequate samples when the inner needle takes a curved course deviated toward the tip and get restored by the cannula.     

Costs and quality of life of multiple sclerosis in the United Kingdom

This cost-of-illness analysis for the United Kingdom is part of a Europe-wide study on the costs of multiple sclerosis (MS). The objective was to analyze the costs and quality of life (utility) related to the level of disease severity. People with MS from a database administered by a UK charity (the MS Trust) were asked to participate in the survey by answering a postal questionnaire. In addition to details on the disease (type of disease, relapses, level of functional disability), the questionnaire asked for information on all resource consumption, medical, non-medical, work absence and informal care as well as utility. The response rate was 19%, and a total of 2048 people were included. The mean age of the cohort was 51 years, and 23% of people were ≥60 years of age. Disease severity was concentrated in people with moderately severe MS (Expanded Disability Status Scale [EDSS] score of 4 to 6.5), with 21, 60 and 19% of people reporting mild, moderate and severe disease, respectively. Costs and utility are highly correlated with disease severity. Mean annual costs for all people in the study increase from approximately £ 12.000 at an EDSS score <4 to almost £ 60.000 at an EDSS score ≥7. In particular, employment rates are reduced from 82% in early disease to 2% at an EDSS score of 8, while the costs of inpatient care, investments, informal care and productivity losses increase by more than tenfold between an EDSS score of 0-1 and a score ≥7. Utility decreases from 0.92 at an EDSS score of 0 to a state worse than death in the most severe state (–0.18 at an EDSS score of 9). Compared to the results in an earlier cost study in the United Kingdom using a comparable methodology, costs have substantially increased, by roughly 40%. Part of the increase is due to a higher use of disease-modifying drugs and, possibly linked with this, a higher use of ambulatory care and services. Another part of the increase is most likely due to an increased age in the current sample, with more patients on early retirement due to MS and more intense use of informal care. However, another reason may lie in the methodology, e.g. different unit costs or differences in the sample distribution, despite a similar mean EDSS score of 5.1.     

Costs and quality of life of multiple sclerosis in Germany

This cost-of-illness analysis based on information from 2973 patients with multiple sclerosis (MS) in Germany is part of a Europe-wide study on the costs of MS. The objective was to analyze the costs and quality of life (QOL) related to the level of disease severity. Patients from six centres (office- and hospital-based physicians) and patients enrolled in a database were asked to participate in the survey; 38% answered a mail questionnaire. In addition to details on the disease (type of disease, relapses, level of functional disability), the questionnaire asked for information on all resource consumption, medical, non-medical, work absence, informal care, as well as QOL (measured as utility). The mean age of the cohort was 45 years, and 18% of patients were 65 years of age or older. Forty-seven percent of patients had mild disease (Expanded Disability Status Scale [EDSS] score 0–3), 36% had moderate disease (EDSS score 4–6.5) and 12% had severe disease (EDSS score ≥7). The mean EDSS score in the sample was 3.8 (median 4.0), with a mean utility of 0.62. Costs and utility are highly correlated with disease severity. Workforce participation decreases from 73% in very early disease to less than 10% in the very late stages, leading to a tenfold rise in productivity losses in the late stages of disease. Hospitalisation and ambulatory visits rise by a factor of 5–6 between early and late disease; investments and services increase from basically no cost to € 2700; and informal care increases by a factor of 27 for patients with an EDSS score of 7 and by a factor of 50 for patients at the very severe end of the EDSS scale (8–9). Hence, total mean costs per patient are determined essentially by the distribution of the severity levels in the sample, increasing from approximately € 18 500 at an EDSS score of 0–1 to € 70 500 at an EDSS score of 8–9. The same is true for utility, which decreases from 0.86 to 0.10 as the disease becomes severe. However, the utility loss compared to the general population is high at all levels of the disease, leading to an estimated loss of 0.2 quality-adjusted life-years per patient. Relapses are associated with a cost of approximately € 3 000 and a utility loss of 0.1 during the quarter in which they occur. Compared with a similar study performed in 1999, resource consumption, with the exception of drugs, is somewhat lower. This is most likely due to a difference in the severity distribution of the two samples and to changes in health-care consumption overall in the country, such as the introduction of diagnosis-related groups (DRGs, Fallpauschalen).