Atmospheric transport patterns and possible consequences for the European North after a nuclear accident

The main purpose of this study is to examine possible impacts and consequences of a hypothetical accident at the Kola nuclear plant in north-west Russia on different geographical regions: Scandinavia, central Europe, European FSU and Taymyr. The period studied is 1991-1996. An isentropic trajectory model has been used to calculate forward trajectories that originated over the nuclear accident region. Atmospheric transport patterns were identified using the isentropic trajectories and a cluster analysis technique. From the trajectory model results, a number of cases were chosen for examination in detail using more complete transport models. For this purpose, the models MATHEW/ADPIC, DERMA and a newly developed FOA Random Displacement Model have been used to simulate the radionuclide transport and contamination in the case of a nuclear accident and their results have been compared with those of the trajectory modelling. Estimation of the long-term consequences for populations after an accident has been performed for several specific dates by empirical models and correlation between fallout and doses to humans on the basis of the Chernobyl accident exposures in Scandinavia.

Plasma selenium level before diagnosis and the risk of prostate cancer development

PURPOSE

Epidemiological studies and a randomized intervention trial suggest that the risk of prostate cancer may be reduced by selenium intake. We investigated whether plasma selenium level before diagnosis correlated with the risk of later developing prostate cancer.

MATERIALS AND METHODS

A case control study was performed on men from the Baltimore Longitudinal Study of Aging registry, including 52 with known prostate cancer and 96 age matched controls with no detectable prostatic disease. Plasma selenium was measured at an average time plus or minus standard deviation of 3.83 +/- 1.85 years before the diagnosis of prostate cancer by graphite furnace atomic absorption spectrophotometry. Adjusted odds ratio and 95% confidence interval were computed with logistic regression.

RESULTS

After correcting for years before diagnosis, body mass index, and smoking and alcohol use history, higher selenium was associated with a lower risk of prostate cancer. Compared with the lowest quartile of selenium (range 8.2 to 10.7 microg./dl.), the odds ratios of the second (10.8 to 11.8), third (11.9 to 13.2) and fourth (13.3 to 18.2) quartiles were 0.15 (95% confidence interval 0.05 to 0.50), 0.21 (0.07 to 0.68) and 0.24 (0.08 to 0.77, respectively, p =0.01). Furthermore, plasma selenium decreased significantly with patient age (p <0.001).

CONCLUSIONS

Low plasma selenium is associated with a 4 to 5-fold increased risk of prostate cancer. These results support the hypothesis that supplemental selenium may reduce the risk of prostate cancer. Because plasma selenium decreases with patient age, supplementation may be particularly beneficial to older men.

Optically active molecule-based magnets: enantioselective self-assembling, optical, and magnetic properties

In this short communication we describe the synthesis and the optical and magnetic properties of optically active three dimensional (3D) bimetallic [Cr-Mn] networks [[Delta Cr(III) Delta Mn(II)(ox)(3)][Delta Ru(II)(bpy)(3)]ClO(4)](n)1 - Delta, [[Lambda Cr(III)Lambda Mn(II)(ox)(3)][Lambda Ru(II) (bpy)(3)]ClO(4)](n) 1 - Lambda and [[Delta Cr(III)Delta Mn(II)(ox)(3)][Delta Ru(II)(bpy)(2)p p y]](n) 2 - Delta,[[Lambda Cr(III)Lambda Mn(II)(ox)(3)][Lambda Ru(II)(bpy)(2)ppy]](n) 2 - Lambda (ox = oxalate, bpy = bipyridine, ppy = phenyl-pyridine).

Plasma selenium level before diagnosis and the risk of prostate cancer development

PURPOSE

Epidemiological studies and a randomized intervention trial suggest that the risk of prostate cancer may be reduced by selenium intake. We investigated whether plasma selenium level before diagnosis correlated with the risk of later developing prostate cancer.

MATERIALS AND METHODS

A case control study was performed on men from the Baltimore Longitudinal Study of Aging registry, including 52 with known prostate cancer and 96 age matched controls with no detectable prostatic disease. Plasma selenium was measured at an average time plus or minus standard deviation of 3.83 +/- 1.85 years before the diagnosis of prostate cancer by graphite furnace atomic absorption spectrophotometry. Adjusted odds ratio and 95% confidence interval were computed with logistic regression.

RESULTS

After correcting for years before diagnosis, body mass index, and smoking and alcohol use history, higher selenium was associated with a lower risk of prostate cancer. Compared with the lowest quartile of selenium (range 8.2 to 10.7 microg./dl.), the odds ratios of the second (10.8 to 11.8), third (11.9 to 13.2) and fourth (13.3 to 18.2) quartiles were 0.15 (95% confidence interval 0.05 to 0.50), 0.21 (0.07 to 0.68) and 0.24 (0.08 to 0.77, respectively, p =0.01). Furthermore, plasma selenium decreased significantly with patient age (p <0.001).

CONCLUSIONS

Low plasma selenium is associated with a 4 to 5-fold increased risk of prostate cancer. These results support the hypothesis that supplemental selenium may reduce the risk of prostate cancer. Because plasma selenium decreases with patient age, supplementation may be particularly beneficial to older men.

Does waist circumference add to the predictive power of the body mass index for coronary risk?

OBJECTIVES

To examine the power of the combined measurements of body mass index (BMI) and waist circumference (WC) for the prediction of abnormality in coronary heart disease risk factors and to determine whether the additional measurement of WC is predictive in older men and women.

RESEARCH METHODS AND PROCEDURES

1190 men and 751 women of the Baltimore Longitudinal Study of Aging were dichotomized into younger (<65 years) and older (65+ years) age groups. Coronary risk factors in the realms of glucose/insulin metabolism, blood pressure, and plasma lipids were assessed. The relationship of BMI and WC, singly and combined, to 10 risk factors for coronary heart disease was examined.

RESULTS

In younger and older men and women, BMI and WC are highly correlated (0.84 to 0.88). BMI and WC are also significantly correlated to all 10 coronary risk factors in younger men and women and to 8 of the 10 in the older men and women. Both partial correlation and logistic regression analyses revealed a modest but significant improvement in the prediction of coronary risk in younger men and women by WC after controlling for the level of BMI. There was no improvement in the older subjects.

DISCUSSION

WC adds only modestly to the prediction of coronary risk in younger subjects once BMI is known, and adds nothing to the production of risk in older subjects.

Multiple effects of artemin on sympathetic neurone generation, survival and growth

To define the role of artemin in sympathetic neurone development, we have studied the effect of artemin on the generation, survival and growth of sympathetic neurones in low-density dissociated cultures of mouse cervical and thoracic paravertebral sympathetic ganglia at stages throughout embryonic and postnatal development. Artemin promoted the proliferation of sympathetic neuroblasts and increased the generation of new neurones in cultures established from E12 to E14 ganglia. Artemin also exerted a transient survival-promoting action on newly generated neurones during these early stages of development. Between E16 and P8, artemin exerted no effect on survival, but by P12, as sympathetic neurones begin to acquire neurotrophic factor independent survival, artemin once again enhanced survival, and by P20 it promoted survival as effectively as nerve growth factor (NGF). During this late period of development, artemin also enhanced the growth of neurites from cultured neurones more effectively than NGF. Confirming the physiological relevance of the mitogenic action of artemin on cultured neuroblasts, there was a marked reduction in the rate of neuroblast proliferation in the sympathetic ganglia of mice lacking the GFRα3 subunit of the artemin receptor. These results indicate that artemin exerts several distinct effects on the generation, survival and growth of sympathetic neurones at different stages of development.

Combination chemotherapy with docetaxel plus vinorelbine in metastatic breast cancer patients with prior exposure to anthracyclines

PURPOSE

To evaluate the anti-tumor activity and tolerance of docetaxel plus vinorelbine in metastatic breast cancer (MBC) patients previously treated with anthracyclines.

PATIENTS AND METHODS

Fifty patients with MBC were treated with docetaxel 75 mg/m2 (subsequently reduced to 60 mg/m2) plus vinorelbine 30 mg/m2 (subsequently reduced to 24 mg/m2). both on day 1, every 3 weeks, for a maximum of six cycles. All patients had previously received anthracyclines as adjuvant treatment (< 12 months disease-free interval) or first-line therapy for MBC. Thirty-seven patients had received at least one prior regimen for MBC. Twenty-five patients had prior high-dose chemotherapy with stem-cell rescue. Thirty patients had multiple metastatic sites. Liver and lung disease were the predominant metastatic site in 31 patients.

RESULTS

Forty-nine patients were assessable for response. Nineteen patients achieved a partial response and four a complete response (overall response rate, 46%; 95% confidence interval (95% CI): 32%-60%). Fourteen patients (28%) had stable disease on treatment. Median Kaplan-Meier estimated progression-free and duration of response times are 21 and 29 weeks. Median survival time is 47 weeks. Hematological dose-limiting toxicity, prompted a 20% dose reduction for both drugs after the first thirteen patients were treated. Neutropenia > or = grade 3 occurred in nineteen (34%) patients, neutropenic fever in 15 (7) courses, and mucositis > or = grade 3 in 6 (3%) courses.

CONCLUSIONS

The combination of docetaxel plus vinorelbine on day 1 every 3 weeks is feasible and active in MBC patients with prior anthracycline exposure. This regimen is safe, well-tolerated and convenient for the patients.

Coupling Met to specific pathways results in distinct developmental outcomes

Receptor tyrosine kinases (RTKs) mediate distinct biological responses by stimulating similar intracellular signaling pathways. Whether the specificity of the response is determined by qualitative or quantitative differences in signaling output is not known. We addressed this question in vivo by replacing the multifunctional docking sites of Met, the receptor for hepatocyte growth factor, with specific binding motifs for phosphatidylinositol-3 kinase, Src tyrosine kinase, or Grb2 (Met(2P), Met(2S), and Met(2G), respectively). All three mutants retained normal signaling through the multiadaptor Gab1, but differentially recruited specific effectors. While Met(2G) mice developed normally, Met(2P) and Met(2S) mice were loss-of-function mutants displaying different phenotypes and rescue of distinct tissues. These data indicate that RTK-mediated activation of specific signaling pathways is required to fulfill cell-specific functions in vivo.

A test of recently proposed BMI standards with respect to old age

The purpose of this study was to investigate the effects of age on the relationship between BMI and multiple coronary risk factors, and to determine whether the BMI classification by NHLBI and WHO is applicable as a predictor of coronary risk factors in older (>65 years) as well as in younger (<65 years) men and women. Effects of age on ten coronary risk factors were examined. Sex differences in the slopes of BMI on risk factors were compared between younger and older subjects in order to examine the effects of age on these relationships. The frequency of risk factor abnormality in individual BMI groups (18.5-24.9, 25.0-29.9, 30.0+) was examined for four age-sex groups. The significance of an age group-BMI interaction term was tested by the logistic regression model to see whether there is a significant difference in the relationship between BMI and the individual risk factor abnormalities between younger and older subjects. Older subjects had significantly higher values for most risk factors than younger subjects. The slopes of BMI on risk factors were different between younger and older subjects for fasting glucose, total, HDL- and LDL-cholesterol in men, and for diastolic blood pressure, total and LDL-cholesterol in women. The proportion of subjects with abnormal risk factor levels in each of the three BMI groups was higher in older than in younger subjects for most risk factors. There was generally a progressive worsening of the risk factor levels with increasing BMI in both age groups. There was no consistent age difference in the relationship between BMI groups and the frequency of risk factor abnormality. We conclude that, although age increases the frequency of most cardiovascular risk factor abnormalities, in general, it does not affect the trend of the relationship between the risk factors and the normal, overweight and obese BMI groups defined by NHLBI and WHO. Therefore, these BMI categories are applicable as predictors of risk factor levels in older as well as in younger men and women.

Spectromicroscopy of boron in human glioblastomas following administration of Na2B12H11SH

Boron neutron capture therapy (BNCT) is an experimental, binary treatment for brain cancer which requires as the first step that tumor tissue is targeted with a boron-10 containing compound. Subsequent exposure to a thermal neutron flux results in destructive, short range nuclear reaction within 10 microm of the boron compound. The success of the therapy requires than the BNCT agents be well localized in tumor, rather than healthy tissue. The MEPHISTO spectromicroscope, which performs microchemical analysis by x-ray absorption near edge structure (XANES) spectroscopy from microscopic areas, has been used to study the distribution of trace quantities of boron in human brain cancer tissues surgically removed from patients first administered with the compound Na2B12H11SH (BSH). The interpretation of XANES spectra is complicated by interference from physiologically present sulfur and phosphorus, which contribute structure in the same energy range as boron. We addressed this problem with the present extensive set of spectra from S, B, and P in relevant compounds. We demonstrate that a linear combination of sulfate, phosphate and BSH XANES can be used to reproduce the spectra acquired on boron-treated human brain tumor tissues. We analyzed human glioblastoma tissue from two patients administered and one not administered with BSH. As well as weak signals attributed to BSH, x-ray absorption spectra acquired from tissue samples detected boron in a reduced chemical state with respect to boron in BSH. This chemical state was characterized by a sharp absorption peak at 188.3 eV. Complementary studies on BSH reference samples were not able to reproduce this chemical state of boron, indicating that it is not an artifact produced during sample preparation or x-ray exposure. These data demonstrate that the chemical state of BSH may be altered by in vivo metabolism.

Effect of aging on the relationship between multiple risk factors and waist circumference

OBJECTIVE

To examine the relationship between various coronary risk factors and the different levels of fat distribution in younger (<65 years) and older (> or = 65 years) men and women, using the classifications proposed by the National Heart, Lung and Blood Institute (NHLBI) and the World Health Organization (WHO).

DESIGN

Cross-sectional study of subjects enrolled in the Baltimore Longitudinal Study of Aging.

MEASUREMENTS

Systolic blood pressure, diastolic blood pressure, fasting glucose, 2-hour glucose, fasting insulin, homeostasis model assessment insulin resistance (HOMAIR), triglyceride, total cholesterol, high-density lipoprotein (HDL)-cholesterol, and low-density lipoprotein (LDL)-cholesterol were measured as risk factors. The proportion of subjects with abnormal risk factor levels by waist circumference classifications was determined in the age and gender subgroups.

RESULTS

There were significant adverse effects of age per se on all risk factors with the exception of fasting insulin and HOMAIR in both men and women, total cholesterol in men, and diastolic blood pressure in women. HDL-cholesterol was higher in older subjects. There were significant correlations between waist circumference and all of the risk factors in the younger group. Waist circumference did not have a significant correlation with total cholesterol in older men, or with total cholesterol and LDL-cholesterol in older women. The proportion of subjects with an abnormal risk factor level increased with increasing waist circumference for most risk factors in both younger and older subjects, but proportions of subjects in each individual waist group were higher in older than in younger groups for systolic blood pressure, diastolic blood pressure, fasting glucose, and 2-hour glucose in men, and for systolic blood pressure, fasting glucose, 2-hour glucose, total and LDL-cholesterol, and triglyceride in women.

CONCLUSIONS

Our data indicate that the waist circumference cutpoints proposed by NHLBI and WHO standards are useful for the prediction of cardiovascular disease risk factors in older as well as in younger men and women.

Charging phenomena in PEEM imaging and spectroscopy

Spectromicroscopy with the imaging technique of X-ray photoelectron emission microscopy (X-PEEM) is a microchemical analytical tool installed in many synchrotron radiation laboratories, and which is finding application in diverse fields of research. The method of sample analysis, X-ray absorption spectroscopy, does not encounter the same problems as X-ray photoemission spectroscopy when sample charging occurs, hence even good insulators may often be analyzed without any apparent artifacts in images or spectra. We show, however, that charging effects cannot be neglected. We model the effect of surface charge formation on the secondary electron yield from uniform samples to demonstrate that surface charge primarily reduces the yield of electrons which may contribute to the detected signal. We illustrate that on non-uniform insulating samples, localized centers of charge may substantially affect microscope imaging and resolution as the electrostatic field close to the surface is distorted. Finally, in certain circumstances non-uniform surface charge may lead to unexpected lineshapes in X-ray absorption spectra causing, in some extreme cases, negative spectra. These negative spectra are explained, and several strategies are reviewed to minimize the impact of sample charging when analyzing poorly conducting samples of any nature.

UV-ozone ashing of cells and tissues for spatially resolved trace element analysis

UV/ozone ashing of thin tissue sections and cell cultures is a simple technique to enhance relative elemental concentrations, while maintaining their spatial location at the sub-micron level. This approach may enhance the capability of spatially resolved analysis techniques to detect the distribution of trace elements in biological matrices. We present results from light microscopy and x-ray spectromicroscopy studies of tissues and cells demonstrating that the micro-structure is very well conserved. We show the signal enhancement resulting from the removal of carbon, which allows otherwise undetectable gadolinium to be mapped in cancer tissue for a novel neutron capture therapy.

Longitudinal change in height of men and women: implications for interpretation of the body mass index: the Baltimore Longitudinal Study of Aging

Age differences in height derived from cross-sectional studies can be the result of differential secular influences among the age cohorts. To determine the magnitude of height loss that accompanies aging, longitudinal studies are required. The authors studied 2,084 men and women aged 17-94 years enrolled from 1958 to 1993 in the Baltimore Longitudinal Study of Aging, Baltimore, Maryland. On average, men's height was measured nine times during 15 years and women's height five times during 9 years. The rate of decrease in height was greater for women than for men. For both sexes, height loss began at about age 30 years and accelerated with increasing age. Cumulative height loss from age 30 to 70 years averaged about 3 cm for men and 5 cm for women; by age 80 years, it increased to 5 cm for men and 8 cm for women. This degree of height loss would account for an "artifactual" increase in body mass index of approximately 0.7 kg/m2 for men and 1.6 kg/m2 for women by age 70 years that increases to 1.4 and 2.6 kg/m2, respectively, by age 80 years. True height loss with aging must be taken into account when height (or indexes based on height) is used in physiologic or clinical studies.

Regulation of neurotrophin receptor expression by retinoic acid in mouse sympathetic neuroblasts

We have studied the effect of retinoic acid on the expression of the neurotrophin receptors trkA, trkC, and p75 by neuroblasts and neurons at different axial levels along the embryonic mouse paravertebral sympathetic chain. In dissociated cultures of sympathetic neuroblasts, retinoic acid inhibited the developmental increase in trkA mRNA expression and the developmental decrease in trkC mRNA expression that normally occurs in these cells but did not affect p75 mRNA expression. At higher concentrations, retinoic acid also increased the proliferation of sympathetic neuroblasts. After sympathetic neuroblasts became postmitotic, retinoic acid no longer affected receptor expression. Studies with retinoic acid receptor agonists and antagonists indicated that the effects of retinoic acid on neurotrophin receptor expression were mediated mainly by alpha retinoic acid receptors, not beta or gamma receptors. The observation that alpha-antagonists increased trkA mRNA expression in intact sympathetic ganglion explants suggests that endogenous retinoic acid is a physiological regulator of trkA receptor expression.

Cell ashing for trace element analysis: A new approach based on ultraviolet/ozone

We studied a new approach to cell ashing based on illuminating the specimens with a low-pressure mercury discharge lamp. We analyzed with synchrotron spectromicroscopy its effects on different physiological elements in neurobiological specimens. Our results demonstrate that carbon is removed, whereas phosphorus, calcium, potassium, and sulfur are retained and their relative concentrations are enhanced. Applied to trace elements, this technique will enhance their practical detectability.

Multiple roles for hepatocyte growth factor in sympathetic neuron development

We have studied the role of hepatocyte growth factor (HGF)/Met signaling in the development of sympathetic neuroblasts and neurons. Anti-HGF antibodies reduced the number of sympathetic neuroblasts that differentiated into neurons, but neither anti-HGF antibodies nor HGF affected neuroblast proliferation. Anti-HGF antibodies also reduced the survival of neuroblasts but not sympathetic neurons. HGF greatly enhanced the neurite outgrowth of NGF-dependent sympathetic neurons throughout development. These in vitro effects of anti-HGF antibodies and HGF were abolished by a disabling mutation of Met, the HGF receptor tyrosine kinase. The Met mutation also increased sympathetic neuroblast apoptosis in vivo. Because Met and HGF are expressed in sympathetic ganglia throughout development, it is possible that the multiple effects of HGF/Met signaling on sympathetic neuroblasts and neurons occur in part by an autocrine mechanism.

Cessation of cocaine use during pregnancy: effects of contingency management interventions on maintaining abstinence and complying with prenatal care

Previous studies have reported cessation of cocaine use in pregnant women prior to treatment entry. This study examined the relative effectiveness of adjunctive contingency management interventions in maintaining abstinence and enhancing compliance with prenatal care in this unique population. Pregnant cocaine-dependent women who had used the drug during this pregnancy but had ceased use prior to study entry (N = 12) were randomly assigned to one of two treatment groups. All patients received a multifaceted treatment including behaviorally based drug counseling and weekly prenatal visits. Patients in the experimental condition also received contingent reinforcement for cocaine abstinence and attendance at prenatal visits. There was a high rate of retention and abstinence from cocaine in both groups. However, patients in the experimental group had a higher rate of attendance at prenatal visits, and none of the patients in this group experienced adverse perinatal outcome(s), compared to 80% of patients in the control group. This finding has important implications for cost-effective treatments and prevention of illness.

The effect of ashing on cells: spectromicroscopy of physiological elements

We analyzed the effects of cold oxygen plasma ashing of neurobiological specimens on different elements with synchrotron spectromicroscopy. Our results demonstrate that while carbon is almost completely removed, phosphorus, calcium, potassium, sulfur, and, to some extent, nitrogen are retained and their relative concentration is enhanced.