Superfluid Helium Drops Levitated in High Vacuum

We demonstrate the trapping of millimeter-scale superfluid helium drops in high vacuum. The drops are sufficiently isolated that they remain trapped indefinitely, cool by evaporation to 330 mK, and exhibit mechanical damping that is limited by internal processes. The drops are also shown to host optical whispering gallery modes. The approach described here combines the advantages of multiple techniques, and should offer access to new experimental regimes of cold chemistry, superfluid physics, and optomechanics.

Is water quality in British rivers "better than at any time since the end of the Industrial Revolution"?

We explore the oft-repeated claim that river water quality in Great Britain is "better now than at any time since the Industrial Revolution". We review available data and ancillary evidence for seven different categories of water pollutants: (i) biochemical oxygen demand (BOD) and ammonia; (ii) heavy metals; (iii) sewage-associated organic pollutants (including hormone-like substances, personal care product and pharmaceutical compounds); (iv) macronutrients (nitrogen and phosphorus); (v) pesticides; (vi) acid deposition and (vii) other variables, including natural organic matter and pathogenic micro-organisms. With a few exceptions, observed data are scarce before 1970. However, we can speculate about some of the major water quality pressures which have existed before that. Point-source pollutants are likely to have increased with population growth, increased connection rates to sewerage and industrialisation, although the increased provision of wastewater treatment during the 20th century will have mitigated this to some extent. From 1940 to the 1990s, pressures from nutrients and pesticides associated with agricultural intensification have increased in many areas. In parallel, there was an increase in synthetic organic compounds with a "down-the-drain" disposal pathway. The 1990s saw general reductions in mean concentrations of metals, BOD and ammonia (driven by the EU Urban Waste Water Treatment Directive), a levelling out of nitrate concentrations (driven by the EU Nitrate Directive), a decrease in phosphate loads from both point-and diffuse-sources and some recovery from catchment acidification. The current picture is mixed: water quality in many rivers downstream of urban centres has improved in sanitary terms but not with respect to emerging contaminants, while river quality in catchments with intensive agriculture is likely to remain worse now than before the 1960s. Water quality is still unacceptably poor in some water bodies. This is often a consequence of multiple stressors which need to be better-identified and prioritised to enable continued recovery.

Quantum Optomechanics in a Liquid

We measure the quantum fluctuations of a single acoustic mode in a volume of superfluid He that is coupled to an optical cavity. Specifically, we monitor the Stokes and anti-Stokes light scattered by a standing acoustic wave that is confined by the cavity mirrors. The intensity of these signals (and their cross-correlation) exhibits the characteristic features of the acoustic wave's zero-point motion and the quantum backaction of the intracavity light. While these features are also observed in the vibrations of solid objects and ultracold atomic gases, their observation in superfluid He opens the possibility of exploiting the remarkable properties of this material to access new regimes of quantum optomechanics.

Long-term experiments to investigate irreversibility in sorption of pesticides to soil

Experiments investigated irreversibility in pesticide sorption to soil. Sorption behaviour under abiotic conditions was quantified for chlorotoluron, prometryn and hexaconazole in three soils over periods of up to 274 days. An isotope-exchange procedure was used whereby sorption of (12)C- and (14)C-pesticide isotopes in shaken suspensions of three soils (56-168 days shaking) was followed by substitution of the isotopes in the liquid phase and a 14-day exchange phase. This was followed by forced isotope exchange where the sorbed (14)C material was exchanged by adding an excess of non-radiolabelled compound. Experiments were concluded with solvent extraction and soil combustion to determine remaining radioactivity. Under conditions of continuous shaking, the pesticide-soil systems took around four months to approach sorption equilibrium, resulting in strong asymmetry between the profiles of exchange for isotopes of all three compounds. Physically entrapped residues were released back into solution under the steep concentration gradient of forced isotope exchange and small amounts of radioactivity were still being released at the termination of the experiment. The profiles of exchange did not deviate markedly from ideal behaviour based on the assumption that sorption is fully reversible. Whilst the timescales for release of sorbed residues back into solution were very long, soil combustion at study termination only yielded <1-2% of applied radioactivity; this confirms that sorption processes under abiotic soil conditions were overwhelmingly reversible for this set of compounds and soils.

Telephone-delivered behavioral intervention among blacks with sleep apnea and metabolic syndrome: study protocol for a randomized controlled trial

Background

Lack of adherence to recommended treatment for obstructive sleep apnea remains an ongoing public health challenge. Despite evidence that continuous positive airway pressure (CPAP) is effective and improves overall quality of life, adherence with the use of CPAP in certain racial/ethnic groups, especially blacks, is suboptimal. Evidence indicates that the incidence and prevalence of obstructive sleep apnea are higher among blacks, relative to whites, and blacks are less likely to adhere to recommended treatment compared with other racial/ethnic groups.

Methods

Using a two-arm randomized controlled design, this study will evaluate the effectiveness of a culturally and linguistically tailored telephone-delivered intervention to promote adherence to physician-recommended sleep apnea assessment and treatment among blacks with metabolic syndrome, versus an attention-control arm. The intervention is designed to foster adherence to recommended sleep apnea care using the stages-of-change model. The intervention will be delivered entirely over the telephone. Participants in the intervention arm will receive 10 phone calls to address challenges and barriers to recommended care. Outcomes will be assessed at baseline, and at 6- and 12-months post-randomization.

Discussion

This tailored behavioral intervention will improve adherence to sleep apnea assessment and treatment among blacks with metabolic syndrome. We expect to demonstrate that this intervention modality is feasible in terms of time and cost and can be replicated in populations with similar racial/ethnic backgrounds.

Trial registration

The study is registered at clinicaltrials.gov NCT01946659 (February 2013)

Use of raw or incubated organic wastes as amendments in reducing pesticide leaching through soil columns

Soil amendment with organic wastes is becoming a widespread management practice since it can effectively solve the problems of uncontrolled waste accumulation and improve soil quality. However, when simultaneously applied with pesticides, organic wastes can significantly modify the environmental behaviour of these compounds. This study evaluated the effect of sewage sludges (SS), grape marc (GM) and spent mushroom substrates (SMS) on the leaching of linuron, diazinon and myclobutanil in packed columns of a sandy soil with low organic matter (OM) content (<1%). Soil plus amendments had been incubated for one month (1 m) or 12 months (12 m). Data from the experimental breakthrough curves (BTCs) were fitted to the one-dimensional transport model CXTFIT 2.1. All three amendments reduced leaching of linuron and myclobutanil relative to unamended soil. SMS was the most effective in reducing leaching of these two compounds independent of whether soil was incubated for 1 m or 12 m. Soil amendments increased retardation coefficients (Rexp) by factors of 3 to 5 for linuron, 2 to 4 for diazinon and 3 to 5 for myclobutanil relative to unamended soil. Leaching of diazinon was relatively little affected by soil amendment compared to the other two compounds and both SS and SMS amendment with 1m incubation resulted in enhanced leaching of diazinon. The leaching data for linuron and myclobutanil were well described by CXTFIT (mean square error, MSE<4.9·10(-7) and MSE<7.0·10(-7), respectively) whereas those of diazinon were less well fitted (MSE<2.1·10(-6)). The BTCs for pesticides were similar in soils incubated for one month or one year, indicating that the effect of amendment on leaching persists over relatively long periods of time.

Cardiovascular risk assessment: addition of CKD and race to the Framingham equation

BACKGROUND/AIMS

The value of the Framingham equation in predicting cardiovascular risk in African Americans and patients with chronic kidney disease (CKD) is unclear. The purpose of the study was to evaluate whether the addition of CKD and race to the Framingham equation improves risk stratification in hypertensive patients.

METHODS

Participants in the ALLHAT were studied. Those randomized to doxazosin, older than 74 years, and those with a history of coronary heart disease were excluded. Two risk stratification models were developed using Cox proportional hazards models in a two-thirds developmental sample. The first model included the traditional Framingham risk factors. The second model included the traditional risk factors plus CKD, defined by estimated glomerular filtration rate categories, and stratification by race (black vs non-black). The primary outcome was a composite of fatal coronary heart disease, nonfatal myocardial infarction, coronary revascularization, and hospitalized angina.

RESULTS

There were a total of 19,811 eligible subjects. In the validation cohort, there was no difference in C-statistics between the Framingham equation and the ALLHAT model including CKD and race. This was consistent across subgroups by race and sex and among those with CKD. One exception was among Non-Black women where the C-statistic was higher for the Framingham equation (0.68 vs 0.65, P = .02). In addition, net reclassification improvement was not significant for any subgroup based on race and sex, ranging from -5.5% to 4.4%.

CONCLUSION

The addition of CKD status and stratification by race does not improve risk prediction in high-risk hypertensive patients.

Long-term renal and cardiovascular outcomes in Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) participants by baseline estimated GFR

BACKGROUND AND OBJECTIVES

CKD is common among older patients. This article assesses long-term renal and cardiovascular outcomes in older high-risk hypertensive patients, stratified by baseline estimated GFR (eGFR), and long-term outcome efficacy of 5-year first-step treatment with amlodipine or lisinopril, each compared with chlorthalidone.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was a long-term post-trial follow-up of hypertensive participants (n=31,350), aged ≥55 years, randomized to receive chlorthalidone, amlodipine, or lisinopril for 4-8 years at 593 centers. Participants were stratified by baseline eGFR (ml/min per 1.73 m(2)) as follows: normal/increased (≥90; n=8027), mild reduction (60-89; n=17,778), and moderate/severe reduction (<60; n=5545). Outcomes were cardiovascular mortality (primary outcome), total mortality, coronary heart disease, cardiovascular disease, stroke, heart failure, and ESRD.

RESULTS

After an average 8.8-year follow-up, total mortality was significantly higher in participants with moderate/severe eGFR reduction compared with those with normal and mildly reduced eGFR (P<0.001). In participants with an eGFR <60, there was no significant difference in cardiovascular mortality between chlorthalidone and amlodipine (P=0.64), or chlorthalidone and lisinopril (P=0.56). Likewise, no significant differences were observed for total mortality, coronary heart disease, cardiovascular disease, stroke, or ESRD.

CONCLUSIONS

CKD is associated with significantly higher long-term risk of cardiovascular events and mortality in older hypertensive patients. By eGFR stratum, 5-year treatment with amlodipine or lisinopril was not superior to chlorthalidone in preventing cardiovascular events, mortality, or ESRD during 9-year follow-up. Because data on proteinuria were not available, these findings may not be extrapolated to proteinuric CKD.

Sensitivity analysis for the SimpleTreat model to simulate fate of chemicals in sewage treatment plants

SimpleTreat 3.1 predicts the distribution and elimination of chemicals by sewage treatment. The model is used as the default calculation in EUSES 2.0 to estimate exposure concentration in the receiving water, soil and air. A sensitivity analysis was performed to rank input parameters according to their influence on model predictions. Triclosan was selected for the base case. The sewage flow, degradation rates and parameters describing the raw sewage were shown to be the most sensitive inputs. The pH and dissociation constant are very sensitive parameters when working with ionisable compounds. Variation in certain input parameters was propagated through the model to yield greater variation in output parameters with a maximum ratio of 4.0. SimpleTreat 3.1 is a steady state model describing a highly non-steady system. A large variability in the most sensitive parameters is expected within a single sewage plant and parameters should therefore be selected to cover this variability.

Cardiovascular disease risk reduction with sleep apnea treatment

Cardiovascular diseases are the leading cause of death among adults in developed countries. An increase in prevalent cardiovascular risk factors (e.g., obesity, hypertension and diabetes) has led to a concerted effort to raise awareness of the need to use evidence-based strategies to help patients at risk of developing cardiovascular disease and to reduce their likelihood of suffering a stroke. Sleep apnea has emerged as an important risk factor for the development of cardiovascular disease. Epidemiologic and clinical evidence has prompted the American Heart Association to issue a scientific statement describing the need to recognize sleep apnea as an important target for therapy in reducing cardiovascular disease risks. This article examines evidence supporting associations of sleep apnea with cardiovascular disease and considers evidence suggesting cardiovascular risk reductions through sleep apnea treatment. Perspectives on emerging therapeutic approaches and promising areas of clinical and experimental research are also discussed.

Sleep duration and the risk of diabetes mellitus: epidemiologic evidence and pathophysiologic insights

Evidence from well-defined cohort studies has shown that short sleep, through sleep fragmentation caused by obstructive sleep apnea (OSA) or behavioral sleep curtailment because of lifestyle choices, is associated with increased incidence of diabetes. In this report, we review epidemiologic and clinical data suggesting that OSA is involved in the pathogenesis of altered glucose metabolism. Evidence suggesting increased risk of developing diabetes resulting from curtailed sleep duration is also considered. Proposed mechanisms explaining associations between short sleep and diabetes are examined and clinical management of OSA among patients with diabetes is discussed.

Anxiety and cardiovascular symptoms: the modulating role of insomnia

BACKGROUND

Anxiety and insomnia are associated with cardiovascular (CV) symptoms. We assessed whether the relation between anxiety and CV symptoms is modulated by insomnia.

METHODS

Independently living women (n = 1,440; mean age = 59.36 +/- 6.53 years) were recruited by cluster sampling technique. We obtained data on demographic characteristics, health beliefs, access to health care, CV symptoms, sleep, stress and anxiety levels.

RESULTS

Overall, 56% of the sample reported insomnia; 46% reported CV symptoms, and 54% were highly anxious. There was a greater likelihood for highly anxious women and those experiencing insomnia to report CV symptoms (r(s) = 0.31* and r(s) = 0.32*, respectively). In logistic regression analysis, the adjusted odds ratios for reporting CV symptoms were 1.39 for patients with insomnia and 2.79 for those with anxiety. With control for insomnia, we observed a 3-fold reduction in the magnitude of the association between anxiety and CV symptoms (r(p) = 0.09*). Stepwise adjustments for sociodemographic factors, CV risk markers, and factors anchoring health beliefs and access to health care showed lesser impact on the relationships. With simultaneous control for those covariates, the correlation was r(p) = 0.13*; * p < 0.01.

CONCLUSION

The association of CV symptoms with anxiety is partly accounted for by insomnia.

The kinetics of sorption by retarded diffusion into soil aggregate pores

This study investigates time-dependent sorption of pesticides in soil aggregates. We tested if the sorption kinetics of pesticides in soil aggregates can be described by modeling diffusion into aggregates for a range of soils and pesticides. Our hypothesis is that the rate of sorption is negatively related to sorption strength due to retardated diffusion. Natural aggregates of 3-5 mm diameter were separated from three soils: a clay, a silty clay loam, and a clay loam. The aggregates were stabilized with alginate gel, and adsorption of azoxystrobin, chlorotoluron, and atrazine was measured in batch experiments with eight equilibration times up to 28 days. Equilibrium sorption appeared to be reached within the 28-day period for each pesticide. An intra-aggregate diffusion model was employed to describe the increase of sorption with time. The model describes diffusion of the dissolved pesticides through the pore space inside the aggregates and sorption on internal surfaces. Sorption could be described by pore diffusion into the aggregates with diffusion coefficients between 0.5 x 10(-10) and 1.5 x 10(-10) m(2) s(-1). The model fits support the theory that pore diffusion is the rate-limiting process for sorption of pesticides in aggregates, although the diffusion coefficients were a factor 3-10 smaller than the theoretical diffusion coefficient for diffusion in water. Comparing the results from the different pesticide-soil combinations showed that the extent of nonequilibrium increased with increasing sorption strength. This confirmed that sorption takes longer to reach equilibrium for pesticides and soils with stronger sorption. The differences between the different pesticides and soils were fully accounted for in the model by stronger retardation of the more strongly sorbed pesticides. The results imply that diffusion into aggregates may be the major time-limiting process for sorption of pesticides in structured soils. Commonly performed sorption experiments with sieved soil fail to account for this process.

Cancer worry and insomnia complaints among American women

One-third of women worrying about breast cancer report impaired ability to function daily. It is unclear whether women who worry about breast cancer would experience more sleep problems than those who do not. Data were obtained from a cross-sectional study of black and white women to investigate the association between breast cancer worry and insomnia complaints. Several questionnaires were administered during face-to-face interviews to elicit health and sociodemographic data. The present analyses focused on black and white women (n = 1,038; age range = 50-70 years) with no cancer antecedents or history. Overall, 62% of the women worried about breast cancer, and 49% reported insomnia complaints. Logistic regression analyses, adjusting for effects of age, ethnicity, family history, and perceived risk of developing breast cancer, yielded an odds ratio for insomnia complaints of 1.52 (95% CI: 1.15-2.02, p < .001) among women reporting breast cancer worry. More than one half of the women worrying about breast cancer were likely to report insomnia complaints, notwithstanding the fact that those women did not have a history of cancer. Although fewer black women reported breast cancer worry and insomnia complaints, they were as affected as white women by the impact of worry on mood and daily activities.

Evaluation of sleep apnea in a sample of black patients

OBJECTIVES

Few minority patients with sleep apnea have been evaluated or treated. This study ascertained adherence rate to referrals for sleep apnea evaluation by primary care physicians in a community-based sample of black patients; it also examined baseline characteristics likely to influence adherence rates.

METHODS

A retrospective chart audit was conducted at a hospital-based sleep clinic. Scrutiny was limited to male and female patients between the ages of 20 and 80 years. Data obtained for this analysis included baseline characteristics from a detailed sleep history and/or screening questionnaires and polysomnographic parameters.

RESULTS

Of the 421 patients referred by their private care physicians, 38% (n=160) adhered to the recommendation for a sleep consultation, but all who showed up for their appointment underwent polysomnographic studies. Logistic regression analyses showed that obesity and daytime sleepiness were the most important factors predicting adherence, with multivariate-adjusted odds ratios of 2.69 [95% CI: 1.54-4.71, p < 0.001] and 6.98 [95% CI: 3.86-12.64, p < 0.001], respectively. Of the patients who underwent a polysomnographic sleep evaluation, 91% received a sleep apnea diagnosis and were treated.

CONCLUSIONS

Black patients may be underutilizing available sleep services, but direct comparisons with other ethnic groups could not be made because of insufficient archival data. While the present study does not identify specific barriers to accessing services for sleep problems, it indicates that blacks who are obese and/or are experiencing daytime sleepiness are likely to adhere to recommendations of their physician. Targeted culturally congruent educational interventions to increase awareness of sleep apnea in black communities might help to increase adherence rate.

Obstructive sleep apnea and cardiovascular disease: role of the metabolic syndrome and its components

Although obstructive sleep apnea and cardiovascular disease have common risk factors, epidemiologic studies show that sleep apnea increases risks for cardiovascular disease independently of individuals' demographic characteristics (i.e., age, sex, and race) or risk markers (i.e., smoking, alcohol, obesity, diabetes, dyslipidemia, atrial fibrillation, and hypertension). Individuals with severe sleep apnea are at increased risk for coronary artery disease, congestive heart failure, and stroke. The underlying mechanisms explaining associations between obstructive sleep apnea and cardiovascular disease are not entirely delineated. Several intermediary mechanisms might be involved including sustained sympathetic activation, intrathoracic pressure changes, and oxidative stress. Other abnormalities such as disorders in coagulation factors, endothelial damage, platelet activation, and increased inflammatory mediators might also play a role in the pathogenesis of cardiovascular disease. Linkage between obstructive sleep apnea and cardiovascular disease is corroborated by evidence that treatment of sleep apnea with continuous positive airway pressure reduces systolic blood pressure, improves left ventricular systolic function, and diminishes platelet activation. Several systematic studies are necessary to explicate complex associations between sleep apnea and cardiovascular disease, which may be compounded by the involvement of diseases comprising the metabolic syndrome (i.e., central obesity, hypertension, diabetes, and dyslipidemia). Large-scale, population-based studies testing causal models linking among sleep apnea, cardiovascular morbidity, and metabolic syndrome are needed.

Symptoms of obstructive sleep apnea in a Caribbean sample

Obstructive sleep apnea (OSA) is a prevalent sleep disorder that disproportionately affects blacks. While clinical and epidemiologic data indicate intraethnic differences in several medical diseases, little is known about whether OSA symptoms differ within the black ethnic group. We estimated the rate of OSA symptoms in a community-based sample of Caribbean-born black men and women. We also ascertained which sociodemographic and/or medical factors were associated with OSA risk. A total of 554 patients (mean age = 48.17 +/- 16.75 years) participated in the study; 55% were women. Data were collected in four primary-care clinics in Brooklyn, NY. A health educator explained the purpose of the study to interested patients and assisted consenting participants in completing questionnaires, which required 15 min to complete. Participants reporting habitual snoring, excessive daytime sleepiness, and sleep fragmentation were considered at high OSA risk. The rate of OSA symptoms was: snoring (45%), excessive daytime sleepiness (33%), and difficulty maintaining sleep (34%). Many reported falling asleep while watching television (47%) or while driving (14%). Based on logistic regression analysis, a history of heart disease was the most important predictor of the likelihood of expressing OSA symptoms, with a corresponding multivariate-adjusted odds ratio of 11 (95% confidence interval = 3.03-40.63). Findings suggest the need to investigate whether Caribbean-born blacks are at greater risk for developing OSA than African Americans and whites. Caribbean-born blacks with a history of heart disease should be a prime target for interventions that promote adequate screening and timely OSA diagnosis.

Sleep duration among black and white Americans: results of the National Health Interview Survey

INTRODUCTION

Epidemiologic studies have shown the importance of habitual sleep duration as an index of health and mortality risks. However, little has been done to ascertain ethnic differences in sleep duration in a national sample. This study compares sleep duration in a sample of black and white participants in the National Health Interview Survey (NHIS).

METHOD

Data were collected from 29,818 Americans (age range 18-85 years) who participated in the 2005 NHIS. The NHIS is a cross-sectional household interview survey that uses a multistage area probability design, thus permitting representative sampling of U.S. households. During face-to-face interviews conducted by trained interviewers from the U.S. Census Bureau, respondents provided demographic data and information about physician-diagnosed chronic conditions, estimated habitual sleep duration and functional capacity, and rated their mood.

RESULTS

Fisher's exact test results indicated that blacks were less likely than whites to report sleeping 7 hours (23% vs. 30%; chi2 = 94, p < 0.0001). Blacks were more likely to experience both short sleep (< or = 5 hours) (12% vs. 8%, chi2 = 44, p < 0.0001) and long sleep (> or = 9 hours) (11% vs. 9%, chi2 = 23, p < 0.0001). Logistic regression analysis, adjusting for differences in sociodemographic factors, depression, functional capacity and medical illnesses, demonstrated that black ethnicity was a significant predictor of extreme sleep duration (Wald = 46, p < 0.0001; OR = 1.35, 95% CI: 1.24-1.47).

DISCUSSION

Independent of several sociodemographic and medical factors, blacks had more prevalent short and long sleep durations, suggesting greater variation in habitual sleep time. Therefore, blacks might be at increased risks of developing medical conditions associated with short and long sleep.

Remediation of waters contaminated with ionic herbicides by sorption on polymerin

This study investigated the sorption of paraquat and 2,4-D on polymerin, the humic acid-like fraction of olive mill wastewater. Effects of pH, contact time, initial concentration and sorbent dosage on the sorption of both herbicides were studied. The sorption mechanism of paraquat on polymerin was consistent with the ion exchange of this herbicide with Ca, Mg and K natively occurring in the sorbent; in contrast, 2,4-D was bound to polymerin by hydrogen bonding. Simulated wastewaters contaminated with paraquat were purified after three sorption cycles on polymerin renewed at each cycle, at a solid/liquid ratio of 0.5, whereas those containing 2,4-D showed a maximal residue removal of 44% after two sorption cycles at the same ratio. The possible application of this model to other water-soluble herbicides, as well as the possible exploitation of polymerin as a bio-filter for the decontamination of pollution point sources is briefly discussed.

Changes in pesticide adsorption with time at high soil to solution ratios

Adsorption of six pesticides (2,4-D, dicamba, fluroxypyr, fluazifop-P, metsulfuron-methyl and flupyrsulfuron-methyl) in nine contrasting soils was measured using two techniques: (i) a classical batch method and (ii) a centrifugation method that allowed the measurement of adsorption at a realistic soil to solution ratio after one and seven days. Although the batch method gived significantly higher values of Kd than the centrifugation method for the more strongly sorbed molecules in the more sorptive soils, it tended to give lower adsorption coefficients compared to the centrifugation method when adsorption was lower. Discrepancies between the two methods were probably mainly due to the vigorous shaking applied in the batch technique that artificially enhances the availability of adsorption sites. This implies that shortly after application, more pesticide may be present in the soil solution and thus be available for degradation, plant uptake or leaching than will be predicted from adsorption coefficient determined using the batch method. Adsorption significantly increased between one and seven days and the extractability of total residues decreased with time. The increase in adsorption was not directly related to the level of adsorption although it was more important in soils containing more organic carbon (p=0.022). These results confirm the importance of time-dependent processes and the necessity to include them in risk assessment procedures. The centrifugation technique is a useful method to measure adsorption of pesticides at realistic soil moisture contents and seems to be an adequate technique to characterise the fraction of pesticide that is available for leaching at a given time after application.

Comparison of efficacy and safety of rosuvastatin versus atorvastatin in African-American patients in a six-week trial

The lipid-modifying effects of statin therapy in hypercholesterolemic African-Americans have not been well characterized. This study compared the efficacy and safety of rosuvastatin and atorvastatin treatment for 6 weeks in hypercholesterolemic African-American adults. In the African American Rosuvastatin Investigation of Efficacy and Safety (ARIES) trial (4522US/0002), 774 adult African-Americans with low-density lipoprotein cholesterol > or = 160 and < or = 300 mg/dl and triglycerides < 400 mg/dl were randomized to receive open-label rosuvastatin 10 or 20 mg or atorvastatin 10 or 20 mg for 6 weeks. At week 6, significantly greater reductions in low-density lipoprotein cholesterol, total cholesterol, non-high-density lipoprotein cholesterol, and apolipoprotein B concentrations, as well as lipoprotein and apolipoprotein ratios, were seen with rosuvastatin versus milligram-equivalent atorvastatin doses (analysis of variance with Bonferroni-adjusted critical p < 0.017 for all comparisons). Rosuvastatin 10 mg also increased high-density lipoprotein cholesterol significantly more than atorvastatin 20 mg (p < 0.017). Although statistical comparisons were not performed, larger proportions of rosuvastatin-treated patients than atorvastatin-treated patients achieved National Cholesterol Education Program Adult Treatment Panel III low-density lipoprotein cholesterol goals. The median high-sensitivity C-reactive protein levels were significantly reduced statistically from baseline with rosuvastatin 20 mg and atorvastatin 20 mg among all patients and with rosuvastatin 10 and 20 mg and atorvastatin 20 mg in those patients with a baseline C-reactive protein level > 2.0 mg/L. The 2 study medications were well tolerated during the 6-week study period. In conclusion, rosuvastatin 10 and 20 mg improved the overall lipid profile of hypercholesterolemic African-Americans better than did milligram-equivalent doses of atorvastatin.

Adsorption of ionisable pesticides in soils

Understanding the fate of a pesticide in soil is fundamental to the accurate assessment of its environmental behaviour and vital in ensuring the safe use of new and existing products. Ionisable pesticides comprise a significant proportion of both existing and new active substances registered for use in agriculture worldwide. This group of pesticides includes chemicals that are frequently found in groundwater and surface waters in many different countries. Despite this, approaches to predict the influence of soil properties on the behaviour of ionisable pesticides in soils are poorly developed. Current regulatory assessments frequently default to methods developed for nonionic chemicals, although it is evident that ionisable compounds do not often react like neutral molecules. This review presents the state of knowledge on the adsorption of ionisable pesticides in soils. It first introduces the issues concerning adsorption and the characteristics of this particular kind of chemical. The mechanisms postulated for the adsorption of ionisable pesticides are then described: these are hydrophobic partitioning, ionic exchange, charge transfer, ligand exchange, cation or water bridging, and the formation of bound residues. Relatively little experimental evidence is available, and we are still unable to determine the quantitative contribution of each process in a particular situation. Knowledge is still lacking concerning phenomena occurring at the surfaces of soil particles. Measurements do not allow determination of the operative pH at the surface of soil particles or in microenvironments, and the influence of ionic strength or competition effects is difficult to assess. Subsequently, the review focuses on the influence of soil properties on adsorption and on potential to predict the behaviour of ionisable pesticides in soils. Unlike hydrophobic compounds, adsorption of ionisable pesticides is highly sensitive to variation in pH. This relationship mainly derives from the different proportion of ionic and neutral forms of the pesticide present at each pH level but also from the presence of surfaces with pH-dependent charges in soils. Soil organic matter generally promotes adsorption, although a negative influence has sometimes been reported. Clay and oxides can also play a significant role in some cases. So far, no modelling approach has been applied successfully to a range of ionisable pesticides to predict their adsorption in soils. The standardization of experimental settings and the application of approaches specific to a particular class of pesticide or different type of soil might be necessary to describe the complexity of interactions among ionisable molecules. Degradation of ionisable pesticides is influenced by soil pH in a particular way that relates to changes in sorption, changes in composition and activity of the microbial community, and to shifts in the balance between different degradative mechanisms.

Cardiovascular risk factors in minorities

Recent clinical trials have confirmed the value of intervention on major risk factors, particularly hypertension and hyperlipidemia, in preventing the progression and clinical sequelae of atherosclerosis. Less is known about the prevalence and impact of atherosclerosis risk factors in minorities. A review of recent literature reporting the prevalence of established and new predictors of atherosclerotic events in minority populations and the inclusion of minorities in clinical trials is presented. The prevalence of risk factors differs considerably in minority populations. The role of "premature" coronary death and the level of some risk factors, particularly obesity and blood pressure in African descendants and high triglycerides, low high-density lipoproteins, and diabetes in some Hispanics, is higher than in whites. With few exceptions, however, minorities have not been included in clinical trials in sufficient numbers to determine whether significant differences in the benefit of risk factor intervention exists. Prevalence of key risk factors differs among minority groups. Risk factor intervention should be pursued in minority groups but with the understanding that clinical trials have not ruled out the possibility of qualitative or quantitative differences in response rates among different groups.

Association of reduced red blood cell deformability and diabetic nephropathy

BACKGROUND

Impaired red blood cell deformability may play a key role in the pathogenesis of chronic vascular complications of diabetes mellitus and progression of renal failure. The present study was conducted to test whether impaired red blood cell deformability is indeed associated with development of diabetic nephropathy.

METHODS

We studied 57 adult type 2 diabetic patients divided into three groups according to serum creatinine concentration. Group I comprised 28 diabetic patients with normal renal function (serum creatinine concentration <1.5 mg/dL, mean 1.0 +/- 0.3 mg/dL). Group II comprised 10 diabetic patients with renal insufficiency (serum creatinine concentration ranging from 2 to 6 mg/dL, mean 3.9 +/- 1.54 mg/dL). Group III consisted of 19 diabetic subjects with end-stage renal disease (ESRD) on hemodialysis (serum creatinine concentration ranging from 7.7 to 14.6 mg/dL, mean 10.1 +/- 2.4 mg/dL). In addition, 11 (mean serum creatinine concentration 4.2 +/- 1.5 mg/dL) and 10 (mean serum creatinine concentration 11.5 +/- 3.6 mg/dL) nondiabetic individuals, matched renal function for the diabetic groups (group II and III, respectively) served as control. Red blood cell deformability, measured by filtration technique, is defined as the filtration rate of erythrocyte suspension through a micropore filter divided by the filtration rate of a physiologic buffer solution.

RESULTS

In the diabetic cohort, we found substantially impaired red blood cell deformability in those with normal renal function (group I). With further renal function loss, an increased impairment in red blood cell deformability was observed. Diabetic patients with renal insufficiency (group II) when compared to non-diabetic controls (renal insufficiency) had a significantly greater impairment in red blood cell deformability (P= 0.01). The nondiabetic cohort (renal insufficiency), on the other hand, manifested significant impairment in red blood cell deformability. Their degree of impairment was statistically higher than that in diabetic patients with normal renal function (P= 0.0005). Interestingly, there was a progressive increase in red blood cell deformability impairment, along with progression of renal insufficiency, and thus no significant difference in the degree of red blood cell deformability impairment was observed between diabetic and nondiabetic patients with ESRD (P= 0.52). There is significant correlation between serum creatinine and impairment in red blood cell deformability in both diabetic (group II plus III) (r= 0.43, P= 0.02) and nondiabetic (r= 0.62, P= 0.003) cohorts.

CONCLUSION

In diabetic patients, early impairment in red blood cell deformability appears in patients with normal renal function, and progressive impairment in red blood cell deformability is associated with renal function loss in all patients regardless of the presence or absence of diabetes.

Clinical assessment of near-infrared spectroscopy for noninvasive diabetes screening

BACKGROUND

Current diabetes screening techniques comprise the fasting plasma glucose (FPG) and oral glucose tolerance tests. Both tests demand patient compliance, and neither test has ideal performance. Near-infrared (NIR) spectroscopy is a noninvasive means of interrogating characteristics of a sample and is evaluated as a novel screening method for type 2 diabetes.

METHODS

One hundred fifty-four patients with and without type 2 diabetes were recruited. Their forearm skin was measured with the NIR spectroscopic system, and a capillary blood glucose measurement was also taken. Sixty-six patients returned for a second visit at a later date. A multivariate model, generated from a separate training study, was employed to produce a quantitative risk marker of disease for each NIR spectrum. Sensitivity and specificity (the probabilities that the NIR method will correctly identify a subject as having diabetes or as not having diabetes, respectively) were calculated. As the NIR method produces a continuous rather than categorical classification, various thresholds were evaluated to give several sensitivity and specificity pairs. Test reproducibility was also determined.

RESULTS

At a false-positive rate of 70%, the NIR test had a sensitivity of 77.7%, which is comparable to the 77.3% sensitivity for the FPG test as reported for the Third National Health and Nutrition Examination Survey (NHANES III) study. The reproducibility of the NIR test was also similar to the FPG test (inter-day agreement rates of 84.2% and 79.2%, respectively).

CONCLUSIONS

A noninvasive NIR spectroscopic measurement of the volar forearm was shown to have comparable performance characteristics with the FPG test. The source of the spectroscopic signal is still uncertain and is the subject of ongoing research.

Noninvasive alcohol testing using diffuse reflectance near-infrared spectroscopy

A diffuse reflectance near-infrared (NIR) spectrometer was evaluated as a noninvasive alternative to breath and blood measurements for in vivo alcohol testing. A hybrid partial least squares (PLS) calibration was constructed using a combination of in vivo and in vitro spectral data. This model was subsequently evaluated for its performance in quantifying alcohol concentrations in vivo using a prospective validation study involving subjects who did not participate in the calibration. The validation study entailed induction of alcohol excursions in ten human subjects and comparison of the noninvasive NIR alcohol measurements to blood and breath alcohol measurements. Blood and breath alcohol measurements were performed at the time of each noninvasive NIR measurement (N = 372), establishing the noninvasive NIR measurement standard error relative to blood alcohol at 4.9 mg/dL (0.0049%). Assessment of the hybrid calibration model's sensitivity and selectivity provided strong evidence that the hybrid calibration yielded measurements that were both sensitive to alcohol and independent of other absorbing analytes in human tissue.

A lysimeter experiment to investigate temporal changes in the availability of pesticide residues for leaching

Leaching of three pesticides (isoproturon, chlorotoluron and triasulfuron) and a tracer (bromide) were determined in four contrasting soils ranging in texture from sandy loam to clay. The compounds were applied to undisturbed columns of soil and four columns for each soil were randomly selected and leached with 24-mm equivalent of water at prescribed time intervals (3, 9, 24, 37 and 57 d after application). A rapid decline in leached loads of isoproturon and chlorotoluron as time from application to irrigation increased was observed in all soils. In contrast, triasulfuron and bromide loads only decreased rapidly in the clay soil. Bromide losses decreased with decreasing clay contents of the soil and therefore with a decrease in structural development. Magnitudes of pesticide losses varied from soil to soil, depending on structural development and the organic carbon content. Pesticide degradation experiments on disturbed and undisturbed soil samples showed that the rapid decline of leached loads with time was faster than could be explained by degradation alone. Five physico-chemical processes are put forward to explain the different patterns of pesticide leached loads observed in the soils: (1) relative extent of preferential flow, (2) sorption capacity of the compounds to the different soils, (3) extent of degradation of the compounds in the soil, (4) variation in sorption kinetics between compounds associated with pesticide diffusion into soil aggregates, and (5) protection of the compounds by a combination of intra-aggregate diffusion and the presence of preferential flow pathways.

Treating azotemia-induced anemia with erythropoietin improves diabetic eye disease

BACKGROUND

Coincidental with the pandemic growth of diabetes as the prime cause of end-stage renal disease (ESRD), blindness attributable to diabetic retinopathy has become a major concern for all those involved in the care of diabetic ESRD patients. Vision loss is linked to progression of proliferative retinopathy and macular edema.

METHODS

Extracted from a study of azotemic anemic pre-ESRD patients treated with erythropoietin, a cohort of five diabetic subjects was reassessed in terms of stability of renal function, changes in blood rheology, and course of diabetic eye disease.

RESULTS

All subjects reported subjective improvement in well-being, including enhanced effort tolerance following an increase in hematocrit from a baseline level of to 29.6 +/- 2.0% to a level of 39.5 +/- 2.4% after one year of treatment with erythropoietin (P = <0.0005). Neither hypertension nor deterioration of renal function was noted in any subject. Three patients with macular edema evinced substantive improvement-based stable vision and documented resolution noted in flourescein angiography.

CONCLUSION

Erythropoietin treatment of anemic azotemic diabetic patients is well tolerated. In a small observational retrospective study of three patients with macular edema, retention of vision and resolution of exudates was noted.

The Prevalence of Reduced Glomerular Filtration Rate in Older Hypertensive Patients and Its Association With Cardiovascular DiseaseA Report From the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial

BACKGROUND

The prevalence of reduced glomerular filtration rate (GFR) in older hypertensive patients and the relationship between level of GFR and cardiovascular disease (CVD) and its risk factors are not well known.

METHODS

We evaluated baseline renal function in 40 514 hypertensive patients 55 years or older who were enrolled in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). We used the simplified Modification of Diet in Renal Disease study equation to estimate GFR and examined the prevalence of CVD in patients with different levels of GFR.

RESULTS

Fifty-seven percent of patients had mild (60-89 mL/min per 1.73 m(2)), 17.2% had moderate (30-59 mL/min per 1.73 m(2)), and 0.6% had severe (<or=29 mL/min per 1.73 m(2)) reductions in GFR. Compared with patients with normal or mildly reduced GFR, patients with moderate or severe reductions in GFR were more likely to have had a prior myocardial infarction or stroke (19.2% and 23.4% vs 28.7% and 26.9%, respectively), have ischemic changes on electrocardiography (ECG) (16.0% and 18.9% vs 24.6% and 34.1%, respectively), and have left ventricular hypertrophy on ECG (ECG-LVH) (3.9% and 4.2% vs 6.0% and 11.2%, respectively). A decrease in GFR of 10 mL/min per 1.73 m(2) was independently associated with a 6% higher risk for CVD and 14% higher risk for ECG-LVH. The increase in risk was marked at a GFR of approximately 60 to 70 mL/min per 1.73 m(2).

CONCLUSIONS

The prevalence of reduced GFR is high in older hypertensive patients. Patients with moderate or severe reduction in GFR are more likely to have a history of CVD and ECG-LVH. Even modest reductions in GFR are independently associated with a higher prevalence of CVD and ECG-LVH.

Using a linked soil model emulator and unsaturated zone leaching model to account for preferential flow when assessing the spatially distributed risk of pesticide leaching to groundwater in England and Wales

Although macropore flow is recognized as an important process for the transport of pesticides through a wide range of soils, none of the existing spatially distributed methods for assessing the risk of pesticide leaching to groundwater account for this phenomenon. The present paper presents a spatially distributed modelling system for predicting pesticide losses to groundwater through micro- and macropore flow paths. The system combines a meta version of the mechanistic, dual porosity, preferential flow pesticide leaching model MACRO (the MACRO emulator), which describes pesticide transport and attenuation in the soil zone, to an attenuation factor leaching model for the unsaturated zone. The development of the emulator was based on the results of over 4000 MACRO model simulations. Model runs describe pesticide leaching for the range of soil types, climate regimes, pesticide properties and application patterns in England and Wales. Linking the MACRO emulator to existing spatial databases of soil, climate and compound-specific loads allowed the prediction of the concentration of pesticide leaching from the base of the soil profile (at 1 m depth) for a wide range of pesticides. Attenuation and retardation of the pesticide during transit through the unsaturated zone to the watertable was simulated using the substrate attenuation factor model AQUAT. The MACRO emulator simulated pesticide loss in 10 of 12 lysimeter soil-pesticide combinations, for which pesticide leaching was shown to occur and also successfully predicted no loss from 3 soil-pesticide combinations. Although the qualitative aspect of leaching was satisfactorily predicted, actual pesticide concentrations in leachate were relatively poorly predicted. At the national scale, the linked MACRO emulator/AQUAT system was found to predict the relative order of, and realistic regional patterns of, pesticide leaching for atrazine, isoproturon, chlorotoluron and lindane. The methodology provides a first-step assessment of the potential for pesticide leaching to groundwater in England and Wales. Further research is required to improve the modelling concept proposed. The system can be used to refine regional groundwater monitoring system designs and sampling strategies and improve the cost-effectiveness of the measures needed to achieve 'good status' of groundwater quality as required by the Water Framework Directive.

Angiotensinogen gene polymorphism at -217 affects basal promoter activity and is associated with hypertension in African-Americans

Hypertension is a serious health problem in Western society, in particular for the African-American population. Although previous studies have suggested that the angiotensinogen (AGT) gene locus is involved in human essential hypertension, the molecular mechanisms involved in hypertension in African-Americans remain unknown. We show that an A/G polymorphism at -217 in the promoter of the AGT gene plays a significant role in hypertension in African-Americans. The frequency of the -217A allele was increased significantly in African-American hypertensive subjects compared with normotensive controls. We also show that the nucleotide sequence of this region of the AGT gene promoter bound strongly to CAAT/enhancer-binding protein (C/EBP) family transcription factors when nucleoside A was present at -217. In addition, we show that reporter constructs containing the human AGT gene promoter with nucleoside A at -217 had increased basal transcriptional activity upon transient transfection in HepG2 cells compared with reporter constructs with nucleoside G at -217. Finally, we show that interleukin-6 treatment in the presence or absence of overexpressed C/EBPbeta increased the promoter activities of reporter constructs containing nucleoside A at -217 compared with reporter constructs containing nucleoside G at -217. Because the AGT gene is expressed primarily in liver and adipose tissue, and C/EBP family transcription factors play an important role in gene expression in these tissues, we propose that increased transcriptional activity of the -217A allele of the human AGT gene is associated with hypertension in African-Americans.

Adsorption and degradation of the weak acid mesotrione in soil and environmental fate implications

The ability of soils to adsorb and degrade pesticides strongly influences their environmental fate. This paper examines the adsorption and degradation of a weak acid, a new herbicide mesotrione 12-[4-(methylsulfonyl)-2-nitrobenzoyl]-1,3-cyclohexanedione], in 15 different soils from Europe and the USA. Experiments were conducted to understand the influence of soil properties, covering a wide range of soil textures, soil pH values (4.4 to 7.5), and organic carbon contents (0.6 to 3.35%). Mesotrione adsorption (Kd values ranged from 0.13 to 5.0 L/kg) was primarily related to soil pH, and to a lesser extent by percent organic carbon (%OC). As soil pH rose. mesotrione Kd values got smaller as mesotrione dissociated from the molecular to anionic form. Mesotrione degradation (half-lives ranged from 4.5 to 32 d) was also related to soil pH, getting shorter as soil pH rose. Simple regression of mesotrione adsorption against soil pH and %OC and against degradation provided a close fit to the data. The correlation between mesotrione adsorption and degradation means that Kd and half-life values are only relevant for use in environmental fate assessment if these values are "paired" for the same soil pH and %OC. The implications were as illustrated for leaching, raising important issues about combining pesticide adsorption and degradation behavior in environmental fate assessments.

Anti-cholinergic bronchodilators versus beta2-sympathomimetic agents for acute exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Inhaled bronchodilators form the mainstay of treatment for acute exacerbations of COPD. Two types of agent are used routinely, either singly or in combination: anticholinergic agents and beta2-sympathomimetic agonists.

OBJECTIVES

To assess the effect of anti-cholinergic agents on lung function and dyspnea in patients with acute exacerbations of COPD, compared with placebo or short-acting beta-2 agonists.

SEARCH STRATEGY

A comprehensive search of the literature was carried out on MEDLINE, EMBASE, CINAHL and the Cochrane COPD Trials Register, using the terms: bronchodilator* OR ipratropium OR oxitropium. References listed in each included trial were searched for additional trial reports.

SELECTION CRITERIA

Studies were included if the participants were adult patients with a known diagnosis of COPD and had symptoms consistent with criteria for acute exacerbation of COPD. All randomized controlled trials that compared inhaled ipratropium bromide or oxitropium bromide to appropriate controls were considered. Appropriate control treatments included placebo, other bronchodilating agents, or combination therapies. Studies of acute asthma or ventilated patients were excluded.

DATA COLLECTION AND ANALYSIS

All trials that appeared to be relevant were assessed by two reviewers who independently selected trials for inclusion. Differences were resolved by consensus.

MAIN RESULTS

Four trials compared the short-term effects of ipratropium bromide vs. a beta2-agonist. Short-term changes in FEV1 (up to 90 minutes) showed no significant difference between beta2-agonist and ipratropium bromide treated patients. The differences were similar among the studies and when combined: Weighted Mean Difference (WMD) 0.0 liters (95% Confidence Interval (95% CI) -0.19, 0.19). There was no significant additional increase in change in FEV1 on adding ipratropium to beta2-agonist: WMD 0.02 liter (95% CI -0.08, 0.12). Long-term effects (24 hours) of the ipratropium bromide and beta2-agonist treatment combination were similar: WMD 0.05 liters (95%CI -0.14, 0.05). Neither of two studies found significant changes in PaO2, either short- or long-term, with ipratropium vs. beta-agonist, although one showed an increase in PaO2 in subjects receiving ipratropium bromide at 60 minutes. Adverse drug reactions included dry mouth and tremor.

REVIEWER'S CONCLUSIONS

There was no evidence that the degree of bronchodilation achieved with ipratropium bromide was greater than that using a short-acting beta2-agonist. The combination of a beta2-agonist and ipratropium did not appear to increase the effect on FEV1 more than either used alone.

Effects of erythropoietin and aminoguanidine on red blood cell deformability in diabetic azotemic and uremic patients

Impaired red blood cell-deformability (RBC-df) is noted in patients with diabetes and may play a role in the pathogenesis of microvasculopathy and nephropathy. We report the effects of erythropoietin (EPO) alone and combined with aminoguanidine (AG) for 1 year on RBC-df in predialysis patients (P-DPs) with renal insufficiency and in end-stage renal disease (ESRD) patients on maintenance hemodialysis (DPs). Nine P-DPs who received EPO 50 U/kg by subcutaneous injection 3 times per week are compared with 5 P-DPs treated without EPO (mean serum creatinine 4.1 +/- 0.1 versus 4.2 +/- 0.6 mg/dL, respectively). Twelve DPs (Kt/V = 1.5 +/- 0.1) were studied. Six DPs received AG 200 mg/every other day by mouth and EPO 50 U/kg by intravenous (IV) injection, and 6 DPs received EPO (50 U/kg) and placebo and served as control. RBC-df improved significantly in 9 P-DPs treated with EPO at 6 months (from 2.7 +/- 0.1 to 1.6 +/- 0.2, P = 0.005). This positive effect was sustained at 12 months (P = 0.005); there was no change in RBC-df in P-DPs receiving usual care without EPO. RBC-df improved significantly and progressively at 6 and 12 months in DPs treated with EPO and AG (from 2.2 +/- 0.2 to 1.8 +/- 0.2; P = 0.01; 1.2 +/- 0.1; P = 0.001, respectively); there was limited improvement in RBC-df in DPs treated with EPO and placebo. We conclude that EPO treatment significantly improved RBC-df in diabetic P-DPs, but EPO alone has no significant effect on RBC-df after 12 months in diabetic DPs. The combination of EPO and AG restores RBC-df to near-normal levels in diabetic DPs. We speculate that the effect of EPO on RBC-df seen in P-DPs and DPs is related to increased synthesis and influx of new and younger RBCs. AG may confer protection of RBCs in DPs by blocking advanced glycosylated end-product (AGE) formation.

Influence of topsoil tilth and soil moisture status on losses of pesticide to drains from a heavy clay soil

Twelve lysimeters with a surface area of 0.5 m2 and a length of 60 cm were taken over mole drains from a Denchworth heavy clay soil and divided into two groups with either a standard agricultural tilth or a finer topsoil tilth. The influence of topsoil tilth on leaching of the herbicide isoproturon and a bromide tracer was evaluated over a winter season. The effect of variations in soil moisture status in the immediate topsoil on leaching of isoproturon, chlorotoluron and linuron was investigated in the following winter season. Here, water inputs were controlled such that lysimeters received 50 mm at a maximum intensity of 2 mm h-1 over a 4-week period with herbicides applied on day 15. Three treatments received the water either all prior to application, all after application, or evenly spread over the 4-week period. Leaching losses of the three herbicides were monitored for a subsequently drainage event. Analysis of covariance showed a significant effect of topsoil tilth and total flow on both the maximum concentrations (P = 0.034) and total losses (P = 0.012) of isoproturon in drainflow. Both concentrations and losses were c 35% smaller from lysimeters with the finer tilth. However, generation of the fine tilth in the field was restricted by a wet autumn and this is not considered a reliable management option for reducing pesticide losses from heavy clay soils. In the second experiment, variation in soil moisture content prior to and after application did not have any significant effect (P < 0.05) upon subsequent losses of the three herbicides to drains.

Coping with a MEDLIB-L service outage

OBJECTIVE

The study assessed the coping strategies of MEDLIB-L subscribers during an unexpected disruption in the list's service.

METHODS

An online survey of MEDLIB-L subscribers was performed following a six-day service outage in August 1999.

RESULTS

Respondents' information needs resulted in two distinct coping strategies. Subscribers without a recognized information need or an information need determined to be not pressing coped by waiting out the interruption. Subscribers with pressing information needs turned to alternative methods of resolving these needs.

CONCLUSIONS

While most respondents missed the list and the assistance that it provided, many did not feel that the outage required significant coping strategies. The outage was viewed as a "minor stressor" and did not require secondary-level assessment of the availability and suitability of alternative resources.

A physiologically based pharmacokinetic model for ethylene oxide in mouse, rat, and human

Ethylene oxide (EO) is widely used as a gaseous sterilant and industrial intermediate and is a direct-acting mutagen and carcinogen. The objective of these studies was to develop physiologically based pharmacokinetic (PB-PK) models for EO to describe the exposure-tissue dose relationship in rodents and humans. We previously reported results describing in vitro and in vivo kinetics of EO metabolism in male and female F344 rats and B6C3F1 mice. These studies were extended by determining the kinetics of EO metabolism in human liver cytosol and microsomes. The results indicate enzymatically catalyzed GSH conjugation via cytosolic glutathione S-transferase (cGST) and hydrolysis via microsomal epoxide hydrolase (mEH) occur in both rodents and humans. The in vitro kinetic constants were scaled to account for cytosolic (cGST) and microsomal (mEH) protein content and incorporated into PB-PK descriptions for mouse, rat, and human. Flow-limited models adequately predicted blood and tissue EO levels, disposition, and elimination kinetics determined experimentally in rats and mice, with the exception of testis concentrations, which were overestimated. Incorporation of a diffusion-limited description for testis improved the ability of the model to describe testis concentrations. The model accounted for nonlinear increases in blood and tissue concentrations that occur in mice on exposure to EO concentrations greater than 200 ppm. Species differences are predicted in the metabolism and exposure-dose relationship, with a nonlinear relationship observed in the mouse as a result of GSH depletion. These models represent an essential step in developing a mechanistically based EO exposure-dose-response description for estimating human risk from exposure to EO.

Regulation of 15-lipoxygenase isozymes and mucin secretion by cytokines in cultured normal human bronchial epithelial cells

OBJECTIVE AND DESIGN

To study the effects of IL-4, IL-13, IL-1beta, IL-8 and TNFalpha on 15-lipoxygenase(15-LO) isozyme expression and mucin secretion in normal human bronchial epithelial cells.

MATERIAL AND METHODS

The effects of IL-4, IL-13, IL-1beta, IL-8 and TNFalpha on 15-LO isoenzyme mRNA and protein expression, total 15-LO enzyme activity and mucin secretion were examined in cultures of normal human bronchial epithelial cells. In addition, in order to determine whether the observed effects on mucin secretion were due to lipoxygenase (LO) products, the effect of the non-selective LO inhibitor nordihydroguaiaretic acid was examined.

RESULTS

IL-4 and IL- 13 selectively enhanced 15-LOa mRNA and protein levels, and total 15-LO enzyme activity. In contrast, no changes were observed in 15-LOb mRNA or protein levels. IL-4 and IL-13 both reduced mucin secretion in this cell type, however the non-selective LO inhibitor nordihydroguaiaretic acid had no effect on this action of IL-4.

CONCLUSIONS

These data demonstrate that IL-4 and IL-13 selectively regulate the expression of the 15-LOa isozyme. However, 15LOa products do not mediate the IL-4-induced reduction in mucin secretion observed in this cell type.

Evaluation of uncalibrated preferential flow models against data for isoproturon movement to drains through a heavy clay soil

The uncalibrated predictive ability of four preferential flow models (CRACK-NP, MACRO/MACRO_DB, PLM, SWAT) has been evaluated against point rates of drainflow and associated concentrations of isoproturon from a highly structured and heterogeneous clay soil in the south of England. Data were available for four plots for a number of storm events in each of three successive growing seasons. The mechanistic models CRACK-NP and MACRO generally gave reasonable estimates of drainflow over the three seasons, but under-estimated concentrations of isoproturon over a prolonged period in the first season and over-estimated them in the two remaining seasons. CRACK-NP simulated maximum concentrations of isoproturon over the first two events of each of the three seasons of 156, 527 and 24.4 micrograms litre-1, respectively, and matched the observed data (465, 65.1 and 0.65 micrograms litre-1) slightly better than MACRO (69.1, 566 and 58.5 micrograms litre-1). Automatic selection of parameters from soils information within MACRO_DB reduced the emphasis on preferential flow relative to the stand-alone version of MACRO. This gave a poor simulation of isoproturon breakthrough and simulated maximum concentrations were 0, 50.1 and 35.1 micrograms litre-1, respectively. The capacity model PLM gave the best overall simulation of total drainflow for the first two events in each season, but over-estimated concentrations of isoproturon (967, 808 and 51.3 micrograms litre-1). The simple model SWAT represented total drainflow reasonably well and gave the best simulation of maximum isoproturon concentrations (140, 80.2 and 8.2 micrograms litre-1). There was no clear advantage here in using the mechanistic models rather than the simpler models. None of the models tested was able to simulate consistently the data set, and uncalibrated modelling cannot be recommended for such artificially drained heavy clay soils.

Release of PEGylated granulocyte-macrophage colony-stimulating factor from chitosan/glycerol films

We have prepared a new formulation for mucosal delivery of GM-CSF or PEGylated GM-CSF based on a chitosan carrier plus added glycerol to control the rate of release of the protein. Thin dry films comprised of various weight ratios of chitosan to glycerol and containing either granulocyte-macrophage colony-stimulating factor (GM-CSF) or PEGylated GM-CSF, PEG-(GM-CSF), were prepared. The amount of GM-CSF or PEG-(GM-CSF) released from the chitosan/glycerol films was determined using size exclusion high performance liquid chromatography (HPLC-SEC). The amount of PEG-(GM-CSF) released from the films decreased with an increase in the amount of glycerol present in the film. In parallel with this, films with higher glycerol content exhibited a lower degree of equilibrium swelling when immersed in release media. pH measurements of the release media and analysis of the dried films by Fourier-transform infrared spectroscopy (FTIR) suggested that the amount of residual acetic acid in the dry films decreased as the glycerol content increased. This indicates that glycerol may act by displacing and releasing bound acetic acid from the chitosan molecules, resulting in chitosan--glycerol hydrogen bond formation as the film dries. Further, it was found that the release rate and the amount of PEG-(GM-CSF) released decreased with increasing molecular weight of the conjugated PEG. This effect was not observed with films containing physical mixtures of PEG and GM-CSF. The decrease in the fraction of PEG-(GM-CSF) released with increasing PEG molecular weight is believed to be due to the increased steric hindrance of the PEGylated protein molecule during its diffusion out of the swollen chitosan/glycerol film.

Prior exposure to aged and diluted sidestream cigarette smoke impairs bronchiolar injury and repair

The bronchiolar injury/repair response to naphthalene (NA) in mice includes acute distal airway epithelial injury that is followed by epithelial proliferation and redifferentiation, which result in repair of the epithelium within 14 days. To test whether prior exposure to aged and diluted sidestream cigarette smoke (TS) would alter the injury/repair response of the airway epithelium, adult mice were exposed to either filtered air (FA) or smoke for 5 days before injection with either corn oil carrier (CO) or naphthalene. Mice were killed 1 and 14 days after naphthalene injury. Lung and lobar bronchus were examined and measured using high-resolution epoxyresin sections. The control group (FACOFA) that was exposed to filtered air/corn oil/filtered air contained airway epithelium similar to untreated controls at all airway levels. The group exposed to tobacco smoke/corn oil/filtered air (TSCOFA) contained some rounded cells in the small airways and some expansion of the lateral intercellular space in the larger airways. Necrotic or vacuolated cells were not observed. As expected, the epithelium in the group exposed to filtered air/naphthalene/filtered air (FANAFA) contained many light-staining vacuolated Clara cells and squamated ciliated cells within distal bronchioles during the acute injury phase. Repair (including redifferentiation of epithelial cells and restoration of epithelial thickness) was nearly complete 14 days after injury. The extent of Clara cell injury, as assessed in lobar bronchi, was not different between the four groups. Although the FANAFA group contained greater initial injury in the distal airways at 1 day, the group exposed to tobacco smoke/naphthalene/filtered air (TSNAFA) had the least amount of epithelial repair at 14 days after naphthalene treatment; many terminal bronchioles contained abundant squamated undifferentiated epithelium. We conclude that tobacco smoke exposure prior to injury (1) does not change the target site or target cell type of naphthalene injury, since Clara cells in terminal bronchioles are still selectively injured; (2) results in slightly diminished acute injury from naphthalene in distal bronchioles; and (3) delays bronchiolar epithelial repair.

The neprilysin family in health and disease

The mammalian neprilysin (NEP) family comprises at least seven members: NEP itself, Kell blood group antigen (KELL), the endothelin-converting enzymes (ECE-1 and ECE-2), the enzyme PEX, associated with X-linked hypophosphataemia, "X-converting enzyme" (XCE) a CNS-expressed orphan peptidase and a soluble, secreted endopeptidase (SEP). These zinc metallopeptidases are all type II integral membrane proteins. Where identified, these enzymes have roles in the processing or metabolism of regulatory peptides and therefore represent potential therapeutic targets. A distinct feature of ECE-1 species is their existence as distinct isoforms differing in their N-terminal cytoplasmic tails. These tails play a role in enzyme targeting and turnover with di-leucine and tyrosine-based motifs affecting localization. Additional anchorage of these enzymes can also occur through palmitoylation. Bacterial homologues of the neprilysin family exist, for example the products of the pepO genes from L. lactis and S. parasanguis, and a recently described gene product of P. gingivalis which is an ECE-1 homologue that can catalyse the conversion of big endothelin to endothelin. A genomics based approach to understanding the functions of this proteinase family is aided by the completion of the C. elegans and Drosophila genomes, both of which encode multiple copies of NEP-like enzymes.

Body mass index and the prevalence of hypertension and dyslipidemia

OBJECTIVE

To describe and evaluate relationships between body mass index (BMI) and blood pressure, cholesterol, high-density lipoprotein-cholesterol (HDL-C), and hypertension and dyslipidemia.

RESEARCH METHODS AND PROCEDURES

A national survey of adults in the United States that included measurement of height, weight, blood pressure, and lipids (National Health and Nutrition Examination Survey III 1988-1994). Crude age-adjusted, age-specific means and proportions, and multivariate odds ratios that quantify the association between hypertension or dyslipidemia and BMI, controlling for race/ethnicity, education, and smoking habits are presented.

RESULTS

More than one-half of the adult population is overweight (BMI of 25 to 29.9) or obese (BMI of > or =30). The prevalence of high blood pressure and mean levels of systolic and diastolic blood pressure increased as BMI increased at ages younger than 60 years. The prevalence of high blood cholesterol and mean levels of cholesterol were higher at BMI levels over 25 rather than below 25 but did not increase consistently with increasing BMI above 25. Rates of low HDL-C increased and mean levels of HDL-C decreased as levels of BMI increased. The associations of BMI with high blood pressure and abnormal lipids were statistically significant after controlling for age, race or ethnicity, education, and smoking; odds ratios were highest at ages 20 to 39 but most trends were apparent at older ages. Within BMI categories, hypertension was more prevalent and HDL-C levels were higher in black than white or Mexican American men and women.

DISCUSSION

These data quantify the strong associations of BMI with hypertension and abnormal lipids. They are consistent with the national emphasis on prevention and control of overweight and obesity and indicate that blood pressure and cholesterol measurement and control are especially important for overweight and obese people.

Functional significance of the isoforms of endothelin-converting enzyme-1

The subcellular localization of endothelin-converting enzyme-1 (ECE-1) is a matter of some controversy, further complicated by the discovery of its multiple isoforms. ECE-1 is a critical enzyme in the biosynthesis of the potent vasoconstrictor peptide endothelin (ET), and, as such, represents a potential target for drug therapy in the control of disease states involving the ET system. Knowledge of the precise locations of the isoforms and their regulation would aid in the design of drugs to target specifically ECE-1. In this study, the subcellular localization and potential targeting pathways of the ECE-1 isoforms were investigated. Antipeptide antibodies were raised to the unique N-terminal sequence of ECE-1b and were then used in the investigation of its subcellular distribution. Mutagenesis of proposed targeting sequences within the cytoplasmic tails of the isoforms was carried out to determine their significance in subcellular localization.

Pesticides in rainfall in Europe

Papers and published reports investigating the presence of pesticides in rainfall in Europe were reviewed. Approximately half of the compounds that were analysed for were detected. For those detected, most concentrations were below about 100 ng/l, but larger concentrations, up to a few thousand nanograms per litre, were detected occasionally at most monitoring sites. The most frequently detected compounds were lindane (gamma-HCH) and its isomer (alpha-HCH), which were detected on 90-100% of sampling occasions at most of the sites where they were monitored. For compounds developed more recently, detection was usually limited to the spraying season. A classification of pesticides according to their deposition pattern is proposed.