bluuebunny/crossref_metadata_2025 huggingface dataset:
Value of the clinical history for different users of dermoscopy compared with results of digital image analysis
Authors: Blum A , Hofmann‐Wellenhof R , Luedtke H , Ellwanger U , Steins A , Roehm S , Garbe C , Soyer HP
Published: October 2004

Background  The clinical history of a given pigmented lesion could influence the therapeutic decision. Teledermatology and automated image analysis also hold great potential for revolutionizing dermatology services.

Aim  The aim of this retrospective study was to evaluate the diagnostic accuracy of users with different experiences in dermoscopy with and without information about patients and their history compared with classification by an automated analysing system.

Setting  One hundred and fifty‐seven dermoscopic images of pigmented lesions, taken and proved by histopathology at the Pigmented Lesions Clinic of the Department of Dermatology of the University Tuebingen, Germany, were included.

Methods  All images were viewed by three investigators with different experience: excellent (A), average (B) and beginner (C). In the first dermoscopic classification, no information was available. After 3 months the same images were once more classified by the three investigators, now with the information about the patients and their history. The melanocytic lesions were tested by the Tuebinger Mole Analyser.

Results  For user A the sensitivity, specificity and diagnostic accuracy revealed no improvement on including the history (81.3% to 84.4%, 94.6% to 92.3% and 92.0% to 90.7%), whereas user B clearly improved his results (75.0% to 87.5%, 76.9% to 88.5% and 76.5% to 88.3%). No change in the sensitivity was seen by user C (84.4%), but there was a clear improvement in the specificity (69.2% to 87.7%) and diagnostic accuracy (72.2% to 87.0%). Using the computer algorithm, a sensitivity of 100%, a specificity of 76.9% and a diagnostic accuracy of 81.9% were achieved.

Conclusions  The study revealed results relevant to the use of dermoscopy: (1) continuing dermoscopic education influences the diagnostic accuracy; (2) the history is helpful for averaged users and beginners in dermoscopy; (3) digital image analysis has the highest sensitivity, but a lower specificity compared to the clinicians; and (4) digital dermoscopy could be used for store‐and‐forward systems in teledermoscopy.
Sun awareness in Maltese secondary school students
Authors: Aquilina S , Gauci A Amato , Ellul M , Scerri L
Published: October 2004

Background  Studies indicate that reducing exposure to ultraviolet light during childhood and adolescence decreases the risk of skin cancer. From a young age, children need to be educated about the sun's harmful effects on the skin and how best to protect themselves.

Objective  To help in the design of school‐based interventions to raise sun awareness, a school survey was carried out to identify students’ stereotypes and misconceptions.

Study design  A total of 965 students attending Maltese secondary schools in forms 1, 2 and 3 were surveyed in May 2002, using a structured questionnaire designed to examine students’ sun‐related attitudes and knowledge.

Results  A high level of sun awareness among students was demonstrated, with high scores on knowledge of the effects of the sun on the skin, knowledge of skin cancer and knowledge of sun protection. Girls were clearly more knowledgeable than boys. However, of all the students surveyed, 55% thought that a suntan made them look better and 70% thought that their friends would desire a tan. These views were commoner among the older students. Skin type and hair or eye colour had no bearing on attitudes towards tanning or sun‐related knowledge. The commonest misconceptions were that ‘the sun is bad for your skin only when you get sunburnt’ and that ‘you cannot get too much sun on a cloudy day’. Deliberate suntanning was more frequently reported by girls than by boys and by students in the higher forms.

Conclusion  Attitude change lags behind knowledge. Future school sun awareness interventions need to take into account gender and age differences in students’ attitudes and perspectives. They should aim at motivating attitude change and preventive behaviour through consistent and repeated sun‐education messages that are supported by a sun‐conscious school environment.
Burning mouth syndrome: the efficacy of lipoic acid on subgroups
Authors: Femiano F , Gombos F , Scully C
Published: October 2004

Objective  We have examined the effect of alpha‐lipoic acid (ALA, tioctic acid; Tiobec), a free radical scavenger, on the discomfort of burning mouth syndrome (BMS) in patients who had used tranquillizers previously, compared with those who had not.

Methods  In this study we gave lipoic acid for 2 months to two groups of 20 BMS patients, one of which had previously been treated with tranquillizers.

Results  The results showed greater effectiveness of lipoic acid in BMS patients who had not previously used tranquillizers.

Conclusions  The patients with BMS who had previously been treated with tranquillizers responded poorly to therapy with lipoic acid compared with those who had not received previous psychotropic therapy.
Photopatch testing: a consensus methodology for Europe
Authors: Bruynzeel D.P. , Ferguson J. , Andersen K. , Gonçalo M. , English John , Goossens A. , Holzle E. , Ibbotson S.H. , Lecha M. , Lehmann P. , Leonard F. , Moseley Harry , Pigatto P. , Tanew A.
Published: October 2004

A group of interested European Contact Dermatologists/Photobiologists met to produce a consensus statement on methodology, test materials and interpretation of photopatch testing. While it is recognized that a range of local variables operate throughout Europe, the underlying purpose of the work is to act as an essential preamble to a Pan European Photopatch Test Study focusing particularly on sunscreen chemicals.
Neutrophilic dermatosis of the dorsal hands in a farmer
Authors: Aydin F , Senturk N , Yildiz L , Canturk MT , Turanli AY
Published: October 2004

Neutrophilic dermatosis of the dorsal hands is a recently described disorder, which is similar to Sweet's syndrome. It is characterized by erythematous plaques, pustules and haemorrhagic bullae located solely on the dorsal surface of the hands. We describe a 57‐year‐old man with neutrophilic dermatosis of the dorsal hands that occurred following exposure to a chemical fertilizer. There are few cases reported in the literature regarding neutrophilic dermatosis and the aetiology remains unclear. For the present case, we propose that neutrophilic dermatosis of the dorsal hands might have been induced by the chemical fertilizer.
Oral isotretinoin and haemophilia A
Authors: Bettoli V , Pizzigoni S , Vasina S , Mancino A , Virgili A
Published: October 2004

The effects of oral isotretinoin on the coagulation system are still not well known: some case reports describe thrombocytopenia or thrombocytosis, others present different effects on fibrinolysis. We report a case of severe acne treated with oral isotretinoin in a patient affected with haemophilia A. In this case, which differs from the only other case reported in the literature, oral isotretinoin did not appear to influence the haemophilic patient's need of factor VIII.
Linear IgA dermatosis in an immunosuppressed patient after allogenic bone marrow transplantation
Authors: Schultewolter T , Goos M , Dissemond J
Published: October 2004

Linear IgA dermatosis (LAD) is a well‐recognized acquired subepidermal bullous autoimmune disease. LAD is characterized by clinical, histopathological and immunopathological findings. We report the case of a 38‐year‐old man who suffered from a chronic myeloic leukaemia. Although he received immunosuppressive therapy he developed LAD after an allogenic bone marrow transplantation. After diagnosis of LAD was established we started a successful systemic therapy with dapsone, while continuing the preliminary medication. Here we report for the first time on a possible relationship between LAD and bone marrow transplantation in an immunosuppressed patient.
Linear naevoid psoriasis along lines of Blaschko
Authors: Ghorpade A
Published: October 2004

Congenital linear naevoid psoriasis along Blaschko's lines on the thigh of a 3‐year‐old girl is reported. The history of asymptomatic, erythematous scaly lesions since birth, the peculiar distribution and the histopathology confirmed the diagnosis.
Vitamin and trace metal levels in recessive dystrophic epidermolysis bullosa
Authors: Ingen‐Housz‐Oro S , Blanchet‐Bardon C , Vrillat M , Dubertret L
Published: October 2004

Background  In recessive dystrophic epidermolysis bullosa (RDEB), a good nutritional balance is necessary to obtain healing of the chronic wounds. However, involvement of the oral mucosa and oesophagus stenosis may be responsible for severe nutritional deficiencies.

Objective  In order to propose an adapted nutritional management, we studied the vitamin and trace metal status of 14 RDEB patients.

Methods  Height and weight were measured. Plasma levels of albumin, iron, ferritin, calcium, parathyroid hormone (PTH), folates, vitamins C, D, B12, A, E, B1, B6, PP and B2, zinc, selenium, carnitine and copper were measured.

Results  Most patients had a significant growth retardation. We found iron, vitamin D, C, B6, PP, zinc and selenium deficiencies in 36–70% of the patients, without clinical expression, except in one case. Vitamin B1, 12, B2, A/RBP, E/lipids and carnitine were normal. The three patients with gastrostomy feeding had better growth but still a protein deficiency and sometimes vitamin C, B6, PP, zinc and carnitine deficiencies.

Conclusion  Vitamin and trace metal deficiencies are frequent in RDEB, even in patients receiving gastrostomy feeding, and often go unrecognized. Regular nutritional evaluation is necessary. Dietary advice and supplements should be given. Enteral feeding by gastrostomy should be discussed in early childhood.
Hyperkeratotic nail discoid lupus erythematosus evolving towards systemic lupus erythematosus: therapeutic difficulties
Authors: Richert B , André J , Bourguignon R , De La Brassinne M
Published: October 2004

Nail changes occur in about 25% of systemic lupus erythematosus (SLE) cases. Onycholysis has been reported as the most frequent abnormality in SLE. Nailbed hyperkeratosis may be observed in both SLE and discoid lupus erythematosus (DLE). Involvement of the nail apparatus in DLE is extremely uncommon and never restricted to it. We report on a patient in whom the clinical features on the proximal nailfold were similar to those observed on the skin of a patient with typical DLE. This has, to the best of our knowledge, not yet been reported. The patient also exhibited a very distinctive prominent subungual hyperkeratosis. Interestingly, the patient developed biological alterations suggesting a systematization of the disease. Only a combination of systemic corticoids, retinoids and antimalarials was able to achieve nail improvement and this partial resistance to therapy may be explained by the very unusual subungual hyperkeratosis.
Paraneoplastic vasculitis associated with multiple myeloma
Authors: Sánchez NB , Canedo IF , García‐Patos PE , De Unamuno Pérez P , Benito AV , Pascual AM
Published: October 2004

The association between vasculitis and cancer has been widely reviewed in recent decades. The existence of malignancies in patients with vasculitis has been estimated at about 4.5–8%, haematological neoplasms being the most frequently observed. The haematological malignancies most frequently described are lymphoproliferative diseases such as hairy cell leukaemia and lymphomas. On the contrary, the incidence of paraneoplastic vasculitis in patients with myeloma is low; up to now, we have found nine cases reported on this subject. We report the case of a 73‐year‐old woman who in 1 year showed three outbreaks of acutely painful, purpuric and ulceronecrotic lesions, localized on the lower extremities. Histopathological study demonstrated thrombosis in the arterioles and leucocytoclastic vasculitis. Complementary tests revealed the presence of multiple myeloma.
The role of oxidants and antioxidants in generalized vitiligo at tissue level
Authors: Yildirim M , Baysal V , Inaloz HS , Can M
Published: October 2004

Background  The role of oxidative stress has not been fully understood in the aetiopathogenesis of vitiligo in different studies.

Aim  We aimed to investigate the role of the oxidative stress in the pathogenesis of vitiligo.

Methods  In this study, we examined levels of superoxide dismutase, glutathione peroxidase, malondialdehyde and nitric oxide in tissue of 25 patients with generalized vitiligo and 25 healthy controls.

Results  Our results revealed that levels of superoxide dismutase, glutathione peroxidase and malondialdehyde in tissue were significantly increased in patients with generalized vitiligo (P < 0.05). However, there was no statistically significantly difference between two groups at tissue level of nitric oxide (P > 0.05).

Conclusion  Our results demonstrate the presence of an imbalance in the oxidant–antioxidant system in vitiligo at tissue level and provide further support for a free radical‐mediated damage as an initial pathogenic event in melanocyte degeneration in vitiligo.
The importance of serum creatine phosphokinase level in the early diagnosis and microbiological evaluation of necrotizing fasciitis
Authors: Simonart T , Nakafusa J , Narisawa Y
Published: October 2004

Background  Necrotizing fasciitis (NF) due to group A β‐haemolytic streptococci (GAS) is a rare but still life‐threatening soft‐tissue infection characterized by rapidly spreading necrosis of the muscle fascia and of the surrounding tissues. NF other than that due to GAS involves the participation of one or more anaerobes and/or of non‐group A streptococci, Staphylococcus aureus, enteric organisms, and may be associated with a better outcome. Early diagnosis and treatment, consisting of surgical debridement along with appropriate antibiotic therapy, are required to reduce morbidity and mortality rates.

Objectives  The aim of the study was to analyse the clinical and laboratory findings of patients with GAS NF and with non‐GAS NF, and to identify which characteristics could help to diagnose NF in the early stages of infection.

Methods  We retrospectively analysed the clinical and laboratory findings of 43 cases of GAS and non‐GAS NF that occurred in Belgium (n = 32) and at Saga Medical School (Japan) (n = 11) between May 1984 and December 2001.

Results  GAS NF more frequently occurred in previously healthy individuals than NF due to other pathogens (P < 0.05) but was associated with a poorer prognosis. Both for patients with GAS NF and with non‐GAS NF, the first clinical manifestations often suggested a diagnosis of erysipelas or cellulitis and rarely evoked the correct diagnosis (12% and 15% of the cases, respectively). However, we found that creatine phosphokinase (CPK) values were far higher in patients with GAS NF than in those with non‐GAS NF.

Conclusions  Our data suggest that GAS may exert particular tropism and/or toxicity for muscle, responsible for early muscle necrosis. This indicates that elevated levels of CPK in a patient with erysipelas or cellulitis‐like symptoms should clearly prompt the clinician to exclude the diagnosis of GAS NF.
Pattern formation in the vascular system of monocot and dicot plant species
Authors: Scarpella Enrico , Meijer Annemarie H.
Published: October 2004

Plant vascular tissues are organised in continuous strands, the longitudinal and radial patterns of which are intimately linked to the signals that direct plant architecture as a whole. Therefore, understanding the mechanisms underlying vascular tissue patterning is expected to shed light on patterning events beyond those that organise the vascular system, and thus represents a central issue in plant developmental biology. A number of recent advances, reviewed here, are leading to a more precise definition of the signals that control the formation of vascular tissues and their integration into a larger organismal context.

ContentsSummary209I.Introduction209II.The plant vascular system210III.Ontogeny of the vascular tissues210IV.Procambium development210V.The organisation of the vascular tissues212VI.The regulation of longitudinal vascular pattern formation214VII.The regulation of radial vascular pattern formation220VIII.Genetic screens for vascular development mutants231IX.Genes involved in vascular development identified through reverse genetics approaches235X.Conclusions and perspectives235Note added at the revision stage236Acknowledgements236References236
N : P ratios in terrestrial plants: variation and functional significance
Authors: Güsewell Sabine
Published: October 2004

Nitrogen (N) and phosphorus (P) availability limit plant growth in most terrestrial ecosystems. This review examines how variation in the relative availability of N and P, as reflected by N : P ratios of plant biomass, influences vegetation composition and functioning. Plastic responses of plants to N and P supply cause up to 50‐fold variation in biomass N : P ratios, associated with differences in root allocation, nutrient uptake, biomass turnover and reproductive output. Optimal N : P ratios – those of plants whose growth is equally limited by N and P – depend on species, growth rate, plant age and plant parts. At vegetation level, N : P ratios <10 and >20 often (not always) correspond to N‐ and P‐limited biomass production, as shown by short‐term fertilization experiments; however long‐term effects of fertilization or effects on individual species can be different. N : P ratios are on average higher in graminoids than in forbs, and in stress‐tolerant species compared with ruderals; they correlate negatively with the maximal relative growth rates of species and with their N‐indicator values. At vegetation level, N : P ratios often correlate negatively with biomass production; high N : P ratios promote graminoids and stress tolerators relative to other species, whereas relationships with species richness are not consistent. N : P ratios are influenced by global change, increased atmospheric N deposition, and conservation managment.

Contents

Summary
243

I
Introduction
244

II
Variability of N : P ratios in response to nutrient  supply
244

III
Critical N : P ratios as indicators of nutrient  limitation
248

IV
Interspecific variation in N : P ratios
252

V
Vegetation properties in relation to N : P ratios
255

VI
Implications of N : P ratios for human impacts  on ecosystems
258

VII
Conclusions
259

Acknowledgements
259

References
260
Time Dependent Properties and Performance of a Tubular Solid Oxide
Fuel Cell
Authors: Ju Gang , Reifsnider Kenneth , Huang Xinyu , Du Yanhai
Published: October 2004

Time dependent properties and performance of tubular solid oxide fuel cells were studied numerically and experimentally. The numerical model incorporated local characteristics such as porosity, tortuosity, grain size, and conductivity and was used to evaluate the specific and relative changes in performance caused by the effect of time-dependent material changes of those characteristics. A 500 hour experimental study was conducted at 800°C in 97%H2∕3%H2O on an extruded LSCo-La0.6Sr0.4CoO3∕LSGM∕Ni electrolyte-supported tubular SOFC made in our laboratory. Changes in current density with time (at constant voltage) formed a curve with initial convex (upward) curvature, becoming monotonic decreasing. The microstructure of the constituent layers was examined by scanning electron microscopy. Comparisons between model predictions and experimental observations were made. For the situation modeled and tested, the porosity and ionic conductivity were found to be most influential on performance. More importantly, the effect of porosity is a trade-off between the influence on gas transport and the mixed conductor influence on the electrochemical reactions at the electrode.
Predictors of hearing threshold levels and distortion product otoacoustic emissions among noise exposed young adults
Authors: Seixas N S , Kujawa S G , Norton S , Sheppard L , Neitzel R , Slee A
Published: October 2004

Aim:To examine the relations between noise exposure and other risk factors with hearing function as measured by audiometric thresholds and distortion product otoacoustic emissions.

Methods:A total of 456 subjects were studied (393 apprentices in construction trades and 63 graduate students). Hearing and peripheral auditory function were quantified using standard, automated threshold audiometry, tympanometry, and distortion product otoacoustic emissions (DPOAEs). The analysis addressed relations of noise exposure history and other risk factors with hearing threshold levels (HTLs) and DPOAEs at the baseline test for the cohort.

Results:The cohort had a mean age of 27 (7) years. The construction apprentices reported more noise exposure than students in both their occupational and non-occupational exposure histories. A strong effect of age and years of work in construction was observed at 4, 6, and 8 kHz for both HTLs and DPOAEs. Each year of construction work reported prior to baseline was associated with a 0.7 dB increase in HTL or 0.2 dB decrease DPOAE amplitude. Overall, there was a very similar pattern of effects between the HTLs and DPOAEs.

Conclusions:This analysis shows a relatively good correspondence between the associations of noise exposures and other risk factors with DPOAEs and the associations observed with pure-tone audiometric thresholds in a young adult working population. The results provide further evidence that DPOAEs can be used to assess damage to hearing from a variety of exposures including noise. Clarifying advantages of DPOAEs or HTLs in terms of sensitivity to early manifestations of noise insults, or their utility in predicting future loss in hearing will require longitudinal follow up.
Exposure to cobalt in the production of cobalt and cobalt compounds and its effect on the heart
Authors: Linna A , Oksa P , Groundstroem K , Halkosaari M , Palmroos P , Huikko S , Uitti J
Published: October 2004

Aims:To investigate whether exposure to cobalt in cobalt plants has any measurable effect on the cardiovascular system.

Methods:Occupational, cross sectional study, using a self administered questionnaire, blood pressure measurement, electrocardiography, and laboratory tests in which 203 male workers with at least one year of exposure to cobalt and 94 unexposed controls participated. Echocardiography was performed on a subset of 122 most highly exposed cobalt workers, of which 109 were analysed, and on 60 controls, of which 57 were analysed. Analysis of covariance and a multiple regression analysis were used to evaluate the data.

Results:Two of the echocardiography parameters measured were associated with cobalt exposure. In the higher exposure group the left ventricular isovolumic relaxation time (mean 53.3, 49.1, and 49.7 ms in the high exposure, low exposure, and control groups respectively) and the deceleration time of the velocity of the early rapid filling wave (mean 194.3, 180.5, and 171.7 ms for those in the high exposure, low exposure, and control groups respectively) were prolonged, indicating altered left ventricular relaxation and early filling.

Conclusion:Cumulative exposure to cobalt was found to be associated with the results of Doppler echocardiography measurements, indicating altered diastole. This finding supports the hypothesis that cobalt accumulation in the myocardium could affect myocardial function. Whether this finding has clinical implications remains to be evaluated.
An occupational health intervention programme for workers at risk for early retirement; a randomised controlled trial
Authors: de Boer A G E M , van Beek J-C , Durinck J , Verbeek J H A M , van Dijk F J H
Published: October 2004

Aims:To evaluate an occupational health intervention programme for workers at risk for early retirement.

Methods:Between April 1997 and May 1998, 116 employees of a large company who were older than 50 years indicated that they would not be able to work up to their retirement. They were randomly assigned to an intervention (n = 61) or control group (n = 55). The intervention programme lasted six months and was executed by an occupational physician. Job position and number of sick leave days after two years were collected from the company’s computer database. A questionnaire was sent to the employees at baseline, after six months, and after two years; it included the Work Ability Index, the Utrecht Burn Out Scale, and the Nottingham Health Profile measuring quality of life.

Results:Fewer employees (11%) in the intervention group retired early than in the control group (28%). The total average number of sick leave days in two years was 82.3 for the intervention group and 107.8 for the control group. Six months after baseline, employees in the intervention group had better work ability, less burnout, and better quality of life than employees in the control group. Two years after randomisation no differences between the two groups were found.

Conclusions:This occupational health intervention programme proved to be a promising intervention in the prevention of early retirement.
Use of a crop and job specific exposure matrix for estimating cumulative exposure to triazine herbicides among females in a case-control study in the Central Valley of California
Authors: Young H A , Mills P K , Riordan D , Cress R
Published: October 2004

Aims:To determine if a job exposure matrix (JEM) could be developed using the California Department of Pesticide Regulation Pesticide Usage Database in conjunction with crop, time, and county specific self reported work history and to determine if this was a feasible method to obtain exposure estimates to triazine herbicides.

Methods:Agricultural work histories were gathered from women enrolled in a population based case-control study of ovarian cancer cases and random controls. The work histories were used in conjunction with the database to construct job exposure matrices which took into account weightings for job type, work location, and crop.

Results:Cumulative exposure estimates were determined for 98 study subjects. Mean exposure estimates were similar for cases and controls. The exposure estimates were robust and insensitive to varying job weight assumptions. The estimates from the original weights were highly correlated with those constructed using the conservative and maximum weights. Estimates from all three schemes produced similar multivariate age adjusted odds ratios comparing cases and controls. There was a high degree of agreement in categorised quartiles of exposure between the original and conservative, and original and maximum weights.

Conclusions:The exposure estimate from the JEM provides a ranking of exposure within the study population that can be utilised as an “exposure score” with which to compare groups. Although it is not an absolute exposure measurement, it does offer a substantial advance over dichotomous categories based on self report of herbicide use, particularly when subjects are unlikely to recall specific names and dates of use of herbicides.
Contrasting patterns of mortality and hospital admissions during hot weather and heat waves in Greater London, UK
Authors: Kovats R S , Hajat S , Wilkinson P
Published: October 2004

Background:Epidemiological research has shown that mortality increases during hot weather and heat waves, but little is known about the effect on non-fatal outcomes in the UK.

Aims and Methods:The effects of hot weather and heat waves on emergency hospital admissions were investigated in Greater London, UK, for a range of causes and age groups. Time series analyses were conducted of daily emergency hospital admissions, 1 April 1994 to 31 March 2000, using autoregressive Poisson models with adjustment for long term trend, season, day of week, public holidays, the Christmas period, influenza, relative humidity, air pollution (ozone, PM10), and overdispersion. The effects of heat were modelled using the average of the daily mean temperature over the index and previous two days.

Results:There was no clear evidence of a relation between total emergency hospital admissions and high ambient temperatures, although there was evidence for heat related increases in emergency admissions for respiratory and renal disease, in children under 5, and for respiratory disease in the 75+ age group. During the heat wave of 29 July to 3 August 1995, hospital admissions showed a small non-significant increase: 2.6% (95% CI −2.2 to 7.6), while daily mortality rose by 10.8% (95% CI 2.8 to 19.3) after adjusting for time varying confounders.

Conclusions:The impact of hot weather on mortality is not paralleled by similar magnitude increases in hospital admissions in the UK, which supports the hypothesis that many heat related deaths occur in people before they come to medical attention. This has evident implications for public health, and merits further enquiry.
Daily variation in fine and ultrafine particulate air pollution and urinary concentrations of lung Clara cell protein CC16
Authors: Timonen K L , Hoek G , Heinrich J , Bernard A , Brunekreef B , de Hartog J , Hämeri K , Ibald-Mulli A , Mirme A , Peters A , Tiittanen P , Kreyling W G , Pekkanen J
Published: October 2004

Background:Daily variations in ambient particulate air pollution have been associated with respiratory mortality and morbidity.

Aims:To assess the associations between urinary concentration of lung Clara cell protein CC16, a marker for lung damage, and daily variation in fine and ultrafine particulate air pollution.

Methods:Spot urinary samples (n = 1249) were collected biweekly for six months in subjects with coronary heart disease in Amsterdam, Netherlands (n = 37), Erfurt, Germany (n = 47), and Helsinki, Finland (n = 47). Ambient particulate air pollution was monitored at a central site in each city.

Results:The mean 24 hour number concentration of ultrafine particles was 17.3×103cm−3in Amsterdam, 21.1×103cm−3in Erfurt, and 17.0×103cm−3in Helsinki. The mean 24 hour PM2.5concentrations were 20, 23, and 13 μg/m3, respectively. Daily variation in ultrafine particle levels was not associated with CC16. In contrast, CC16 concentration seemed to increase with increasing levels of PM2.5in Helsinki, especially among subjects with lung disorders. No clear associations were observed in Amsterdam and Erfurt. In Helsinki, the CC16 concentration increased by 20.2% (95% CI 6.9 to 33.5) per 10 μg/m3increase in PM2.5concentration (lag 2). The respective pooled effect estimate was 2.1% (95% CI −1.3 to 5.6).

Conclusion:The results suggest that exposure to particulate air pollution may lead to increased epithelial barrier permeability in lungs.
A cross-sectional study of triallate exposure and neurological health among workers at a pesticide manufacturing and formulating facility
Authors: Sathiakumar N , Delzell E , MacLennan P A , Anne M , Rosenberg N L , Cheng H , Myers S L
Published: October 2004

Aims:To evaluate the relation between an indicator of cumulative exposure to triallate and selected measures of neurological function, including nerve conduction, the prevalence of certain neurological deficits as determined by a medical examination, and vibration perception threshold testing in workers at a pesticide manufacturing plant.

Methods:Subjects were 50 workers with high estimated triallate exposure (“high triallate” group) and 50 workers with no or low triallate exposure (“no/low triallate” group). Industrial hygienists used existing work histories and personal knowledge of plant operations to develop a triallate score. In-person interviews elicited information on past medical history and on occupational and non-occupational exposures. A neurologist carried out nerve conduction tests of the sural and the peroneal nerves, a standardised neurological examination, and vibration sensation testing.

Results:Differences between the high and the no/low triallate groups were minimal for all but one of the six nerve conduction tests, for the prevalence of neurological abnormalities, and for vibration sensation perception. The high triallate group had lower mean sural nerve peak amplitude than the no/low triallate group (11.7v15.2 µV, p = 0.03). This difference was reduced when adjusted for other potential risk factors (12.5v14.5 µV, p = 0.25) and was not associated with cumulative triallate score. We also noted several associations between factors other than triallate and nerve conduction measures.

Conclusion:The results were consistent with the absence of an association between triallate and measures of neurological function.
Do factors in the psychosocial work environment mediate the effect of socioeconomic position on the risk of myocardial infarction? Study from the Copenhagen Centre for Prospective Population Studies
Authors: Andersen I , Burr H , Kristensen T S , Gamborg M , Osler M , Prescott E , Diderichsen F
Published: October 2004

Aim:To investigate whether the effect of socioeconomic position on risk of myocardial infarction (MI) is mediated by differential exposure or differential susceptibility to psychosocial work environment.

Methods:Data were used from three prospective population studies conducted in Copenhagen. A total of 16 214 employees, 44% women, aged 20–75 years, with initial examination between 1974 and 1992 were followed until 1996 for incident (hospital admission or death) MI. Register based information on job categories was used. Psychosocial job exposures were measured indirectly by means of a job exposure matrix based on the Danish Work Environment Cohort Study 1990.

Results:During follow up, 731 subjects were diagnosed with an MI: 610 men and 121 women (35% fatal). The hazards by socioeconomic position showed a graded effect with a hazard ratio (HR) of 1.57 (95% CI 1.23 to 2.03) for unskilled workers compared to executive managers. Despite a strong and graded association in risk of MI related to decision authority and skill discretion, only skill discretion mediated the effect of socioeconomic position. The HR for unskilled workers was reduced to 1.47 (0.93 to 2.31) after adjustment for decision authority and other cardiovascular risk factors, and to 1.07 (0.72 to 1.60) after adjustment for skill discretion and cardiovascular risk factors. No sign of synergy was found.

Conclusions:Decision authority and skill discretion were strongly related to socioeconomic position; and the effect on risk of MI was partially mediated by skill discretion. Improvements in psychosocial work environment, especially possibilities for skill discretion, might contribute to reducing the incidence of MI and social inequality in MI.
The impact of exposure categorisation for grouped analyses of cohort data
Authors: Richardson D B , Loomis D
Published: October 2004

Background:Poisson regression is routinely used in occupational and environmental epidemiology. For typical Poisson regression analyses, person-time and events are tabulated by categorising predictor variables that were originally measured on a continuous scale. In order to estimate a dose-response trend, a researcher must decide how to categorise exposures and how to assign scores to exposure groups.

Aims:To investigate the impact on regression results of decisions about exposure categorisation and score assignment.

Methods:Cohort data were generated by Monte Carlo simulation methods. Exposure categories were defined by quintiles or deciles of the exposure distribution. Scores were assigned to exposure groups based on category midpoint and mean exposure levels. Estimated exposure-disease trends derived via Poisson regression were compared to the “true” association specified for the simulation.

Results:Under the assumption that exposures conform to a lognormal or exponential distribution, trend estimates tend to be negatively biased when scores are assigned based on category midpoints and positively biased when scores are assigned based on cell specific mean values. The degree of bias was greater when exposure categories were defined by quintiles of the exposure distribution than when categories were defined by deciles of the exposure distribution.

Conclusions:The routine practice of exposure categorisation and score assignment introduces exposure misclassification that may be differential with respect to disease status and, consequently, lead to biased exposure-disease trend estimates. When using the Poisson regression method to evaluate exposure-disease trends, such problems can be minimised (but not necessarily eliminated) by forming relatively refined exposure categories based on percentiles of the exposure distribution among cases, and by assigning scores to exposure categories that reflect person-time weighted mean exposure levels.
Decreased fecundity among male lead workers
Authors: Shiau C-Y , Wang J-D , Chen P-C
Published: October 2004

Aims:To investigate time to pregnancy (TTP) in male lead workers in order to determine the dose-response relation between blood lead and decreased fecundity.

Methods:A total of 163 currently employed married male lead battery workers were classified into five categories of exposure based on questionnaire information and annual individual blood lead measurement. Information pertaining to the TTP was collected using personal interviews with 133 men and their spouses, with 280 valid pregnancies. The fecundability ratios (FRs) were calculated with the Cox discrete proportional hazard regression technique to evaluate the effects of lead exposure.

Results:After other factors associated with TTP were controlled for, there was a dose-response relation between blood lead level and TTP. The measured FRs were 0.90 (95% CI 0.61 to 1.34), 0.72 (0.46 to 1.11), 0.52 (0.35 to 0.77), and 0.40 (0.27 to 0.59) for concurrent blood lead levels of <20, 20–29, 30–39, and ⩾40 μg/dl, respectively. Paired self comparison was also performed for 41 couples that had pregnancies prior to lead exposure and pregnancies with male occupational lead exposure. The TTP was prolonged for 0.15 cycles by a 1 μg/dl increase in blood lead.

Conclusions:These results corroborate the hypothesis that a raised blood lead level affects fecundity. A blood lead level of less than 40 μg/dl may still significantly prolong TTP.
Modeling coliforms in storm water plumes
Authors: McCorquodale J Alex , Georgiou Ioannis , Carnelos Susanne , Englande Andrew J
Published: October 2004

The recreational waters near many large cities in the United States and Canada are severely impaired by pathogens that are present in the storm water runoff. In separated sewers the pathogen sources may be cross-flows between the sanitary and storm water systems. This paper presents the methodology that was used in developing a forecasting model for pathogen indicators for recreational sites in the receiving waters of multiple storm water outfalls. The objective of the model is to give a timelier indicator of beach water quality than conventional beach monitoring, which takes about 2 d for laboratory results. The model used for the study was based on the Princeton Ocean Model. The forecasting system consists of nested hydrodynamic models and a bacteria fate–transport submodel. Calibration and validation is based on 6 years of field studies, laboratory analyses, and experiments. The methodology is illustrated by a case study of the impact of storm water flows on the south shore of Lake Pontchartrain, Louisiana, which has been banned for swimming since 1985. The water quality data included: pathogen indicators (fecal coliform, Enterococci, and E. Coli), water chemistry parameters, turbidity, and nutrients. Key words: modeling, water quality, pathogens, fecal coliform, stormwater runoff.
Air flow in sanitary sewer conduits due to wastewater drag: a computational fluid dynamics approach
Authors: Edwini-Bonsu S , Steffler P M
Published: October 2004

An accurate calculation of air flow in sanitary sewer conduits is a key input for improved understanding of odorous-compound emissions, efficient design of ventilation systems, and the occurrence of sewer fabric corrosion. In this study, the driving force of wastewater drag is considered and conceptually viewed as a Couette flow. Both turbulent and laminar flow regimes are modeled. In the turbulent flow regime, the Reynolds-averaged-Navier-Stokes equations are closed with an anisotropic turbulence model that consists of two sub-models: a generalized eddy viscosity mixing length model for the turbulent shear stresses and a semi-empirical model for the turbulent normal stresses. Solution of the resulting set of parabolic equations is implemented in a Gelerkin finite element framework. The predictive performances of the models are in agreement with longitudinal velocity measurements reported in the literature. Although the secondary flows computed are within a few percentage of the main flow velocity, the mean flow field is affected considerably by the secondary currents in every case. The present study suggests that models currently in use for estimating ventilation rates in sewer drains generally over predict the turbulent streamwise mean velocity. Key words: air flow, computational fluid dynamics, finite element method, mixing length, sewer conduit, turbulence-driven secondary currents, ventilation model, wastewater drag.
A review of the impact of chemical pretreatment on low-pressure water treatment membranes
Authors: Farahbakhsh K , Svrcek C , Guest R K , Smith Daniel W
Published: October 2004

Historically, microfiltration (MF) and ultrafiltration (UF) membranes have been used to remove turbidity, particulate matter, and pathogens. Chemical and physical pretreatment, however, can greatly expand the use of MF and UF membrane systems beyond turbidity and microorganism removal. Both MF and UF membrane systems may be used to remove a variety of chemical contaminants such as arsenic, pesticides, taste and odour, iron, and manganese, provided that the proper water chemistry is attained to convert the contaminants to a particulate form. In addition to enhancing the removal of dissolved contaminants, chemical pretreatment processes such as coagulation have been shown to improve membrane performance by reducing the rate of membrane fouling. Several issues, however, still remain to be resolved before chemical pretreatment can be applied optimally in the water treatment membrane field. These issues include the impact of chemical pretreatment on the performance of membrane systems (i.e., membrane reversible fouling, chemical cleaning frequency), the compatibility of these chemicals with membrane materials, the optimum conditions for chemical pretreatment, and overall cost and benefits of chemical pretreatment to MF and UF membrane systems. Key words: microfiltration, ultrafiltration, chemical pretreatment, membrane fouling, natural organic matter, coagulation, clarification, oxidation, contaminant removal, process optimization.
Examination of discrete and counfounding effects of water quality parameters during the inactivation of MS2 phages and Bacillus subtilis pores with free chlorine
Authors: Barbeau Benoit , Huffman Debra , Mysore Chandra , Desjardins Raymond , Prévost Michele
Published: October 2004

The role of water quality (pH, temperature, turbidity, and natural organic matter (NOM)) on the efficacy of chlorine to inactivate Bacillus subtilis spores and MS2 phages was investigated in synthetic waters. A half-factorial statistical experimental design was employed to reduce the number of assays. Temperature and pH were found to be by far the most important variables in explaining chlorine efficacy, that is 78% of the variability in the experimental domain studied (pH, 6.58.5; temperature, 722 °C; dissolved organic carbon (DOC), 05 mg/L, 05 nephelometric turbidity units (NTUs)). The interaction between pH and temperature was also significant, being the third most important factor, explaining 11% of the variability. For both MS2 phages and B. subtilis spores, hypochlorous acid efficacy was less sensitive than hypochlorite ions to a modification of water temperature. Such effect is not taken into account in the current United States Environmental Protection Agency (USEPA) concentrationtime (Ct) tables. Once the consumption of disinfectant by natural organic matter (NOM) was taken into account, the presence of NOM had either no impact on MS2 phage inactivation or significantly improved B. subtilis spore inactivation. The role of inorganic turbidity was either not statistically significant or negligible. Little or no protection was therefore provided by kaolin particles, up to a concentration of 5 mg/L ([Formula: see text]5 NTU).Key words: drinking water, disinfection, spores, MS2 coliphages, chlorine, water quality, turbidity, natural organic matter.
First flush pollution load of urban stormwater runoff
Authors: Taebi Amir , Droste Ronald L
Published: October 2004

In a storm event, a first flush (FF) phenomenon occurs when most of the pollution load is transported in the initial part of the event discharged volume. The objectives of the study were to consider its severity for a number of pollutants as well as to recognize rainfall–runoff characteristics that influence it. The study was conducted in a semi-arid region of a mixed residential and commercial urban catchment in Iran. Ten major rainfall events were monitored for total solids (TS), total suspended solids (TSS), chemical oxygen demand (COD), total nitrogen (TN), Zn, and Pb. Total suspended solids and COD were usually above the permitted discharge. Power and polynomial functions fit well to the normalized curve of the distribution of pollutant load with volume. Discharge loads of TN, Pb, and Zn were approximately uniform. There was a relatively weak FF for TS, TSS, and COD. No correlation between FF load of TS and COD and rainfall–runoff characteristics was observed, but the amount of the FF load of TSS increases when the intensity and duration of a rainfall event increase. Key words: first flush, urban runoff quality, pollution load distribution, event mean concentration, urban stormwater runoff.
Biological oxidation of ferrous ions under acidic conditions using rotating biological contactor
Authors: Kapoor A , Dinardo O , Kuiper A
Published: October 2004

Oxidation of ferrous (Fe2+) ion to ferric (Fe3+) ion under acidic conditions can be achieved by iron oxidizing bacteria. In this research study, oxidation of Fe2+ ions by iron oxidizing bacteria was studied using a bench-scale rotating biological contactor (RBC). Experiments were conducted to investigate the effects of parameters such as hydraulic loading rate (HLR), temperature and Fe2+ concentration at pH 2.0 on Fe2+ oxidation. Oxidation of Fe2+ was observed to decrease with temperature (in the range of 5 to 23 °C). The Fe2+ oxidation rates of 35.3 g Fe2+/(m2·d) and 52.6 g Fe2+/(m2·d) were observed at 5 °C and 21 °C, respectively, at HLR of 0.014 m3/(m2·d). The Fe2+ oxidation rates increased with increase in HLR from 0.014 m3/(m2·d) to 0.055 m3/(m2·d) for a Fe2+ concentration of approximately 3200 mg/L in the RBC feed. The maximum Fe2+ oxidation rate observed in this study was 165 g Fe2+/(m2·d). Iron solids were deposited on the RBC disks and were identified as jarosite. The RBC was able to achieve 50% Fe2+ oxidation efficiency after 24 h of a process upset. Key words: rotating biological contactor, ferrous, ferric, oxidation, acidic mine drainage, hydraulic retention time, hydraulic loading rate.
ASSESSING THE EFFECTS OF THE UNCERTAINTY IN REHEATING ENERGY SCALE ON PRIMORDIAL SPECTRUM AND CMB
Authors: FENG BO , GONG XIAOBO , WANG XIULIAN
Published: October 2004

The details of reheating energy scale ρ reh is largely uncertain today, independent of inflation models. This would induce uncertainty in predicting primordial spectrum. Such uncertainty could be very large, especially for spectra with large running nS. We find that for some inflation models with a large dnS(k)/d ln k, ρ reh could be highly restricted by current CMB observations.