Hospital-based cluster randomised controlled trial to assess effects of a multi-faceted programme on influenza vaccine coverage among hospital healthcare workers and nosocomial influenza in the Netherlands, 2009 to 2011.

Nosocomial influenza is a large burden in hospitals. Despite recommendations from the World Health Organization to vaccinate healthcare workers against influenza, vaccine uptake remains low in most European countries. We performed a pragmatic cluster randomised controlled trial in order to assess the effects of implementing a multi-faceted influenza immunisation programme on vaccine coverage in hospital healthcare workers (HCWs) and on in-patient morbidity. We included hospital HCWs of three intervention and three control University Medical Centers (UMCs), and 3,367 patients. An implementation programme was offered to the intervention UMCs to assess the effects on both vaccine uptake among hospital staff and patient morbidity. In 2009/10, the coverage of seasonal, the first and second dose of pandemic influenza vaccine as well as seasonal vaccine in 2010/11 was higher in intervention UMCs than control UMCs (all p<0.05). At the internal medicine departments of the intervention group with higher vaccine coverage compared to the control group, nosocomial influenza and/or pneumonia was recorded in 3.9% and 9.7% of patients of intervention and control UMCs, respectively (p=0.015). Though potential bias could not be completely ruled out, an increase in vaccine coverage was associated with decreased patient in-hospital morbidity from influenza and/or pneumonia.

Determination of factors required to increase uptake of influenza vaccination among hospital-based healthcare workers.

A questionnaire study was performed in all eight University Medical Centers in The Netherlands to determine the predictors of influenza vaccination compliance in hospital-based healthcare workers (HCWs). Demographical, behavioural and organisational determinants were assessed based on behavioural and implementation models. Multivariable regression analysis was applied to assess the independent predictors for influenza vaccine uptake. Age >40 years, the presence of a chronic illness, awareness of personal risk and awareness of risk of infecting patients, trust in the effectiveness of the vaccine to reduce the risk of infecting patients, the HCWs' duty to do no harm and their duty to ensure continuity of care, finding vaccination useful despite the constant flow of visitors and having knowledge of the Health Council's advice, social influence and convenient time for vaccination were all independently associated with vaccine uptake. The accuracy of the prediction model was very high (area under the receiver operating curve: 0.95). Intervention programmes to increase influenza vaccine uptake among HCWs should target the relevant determinants identified in this study.

Methane fluxes from differentially managed grassland study plots: the important role of CH4 oxidation in grassland with a high potential for CH4 production.

Methane oxidation fluxes were monitored with the closed chamber method in eight treatment plots on a semi-wet grassland site near Giessen, Germany. The management regimes differed in the amount of nitrogen (NH4NO3) fertilizer applied and in the height of the in-ground water table. No inhibition of CH4 oxidation occurred, regardless of the amount of annual N fertilizer applied. Instead, the mean CH4 consumption rates were correlated with the mean soil moisture of the plots. However, the correlation between daily soil water content and corresponding CH4 oxidation rate was always weak. During drought period (late summer) water stress was observed to restrict CH4 oxidation rates. The findings led to the question whether methane production with soil depth might modify the CH4 fluxes measured at the surface. Therefore, two new methods were applied: (1) soil air sampling with silicone probes; and (2) anaerobic incubations of soil cores to test for the methane production potential of the grassland soil. The probe measurements revealed that the CH4 sink capacity of a specific site was related to the vertical length of its CH4 oxidizing column, i.e. the depth of the CH4 producing horizon. Anaerobically incubated soil cores produced large amounts of CH4 comparable with tropical rice paddy soil. Under field conditions, heavy autumnal rain in 1998 led to a dramatic increase of soil CH4 concentrations upto 51 microliters l-1 at a depth of 5 cm. Nevertheless, no CH4 was released when soil surface CH4 fluxes were measured simultaneously. The results thus demonstrate the high CH4 oxidation potential of the thin aerobic topsoil horizon in a non-aquatic ecosystem.

[Cerebral protection with balloon occlusion during carotid artery stent implantation--first experiences]. / Zerebrale Protektion mit Ballonokklusion bei der Stentimplantation der A. carotis--Erste Erfahrungen.

PURPOSE: To assess the technical feasibility and the results of cerebral protection with the GuardWire Plus Temporary Occlusion & Aspiration System during carotid artery stenting for high-grade stenosis. PATIENTS AND METHODS: In 20 patients 20 carotid artery stenoses were treated with stent placement under cerebral protection. A contralateral carotid occlusion was an exclusion criteria for the use of the protection device. In all cases only aspiration, but no flushing was used before deflation of the occlusion balloon. In 17 of 20 patients diffusion-weighted (DW-)MRT imaging of the brain was performed before and 24 hours after the procedure. RESULTS: The stent implantation was successfully performed in all patients. In 3 patients neurologic symptoms occurred during the occlusion time. In these 3 patients the symptoms immediately disappeared after deflation of the balloon. In one case there was dilatation of the internal carotid artery at the site of the balloon inflation. In 3 of the 17 DW-MR images new ipsilateral cerebral lesions, in one case a new contralateral lesion occurred after the procedure. CONCLUSIONS: The cerebral protection procedure is technically feasible. The occlusion of the internal carotid artery was not tolerated by all patients. The DW-MR imaging demonstrated cerebral lesions indicating the occurrence of cerebral microemboli during the procedure. Further investigations are necessary to determine if the use of the cerebral protection device will improve the results of the carotid artery stenting for high-grade stenoses.

A new flux-orientated concept to derive critical levels for ozone to protect vegetation.

The current European critical levels for ozone (O3) to protect crops, natural and semi-natural vegetation and forest trees are based on a relative small number of open-top chamber experiments with a very limited number of plant species. Therefore, the working group "Effects of Ozone on Plants" of the Commission on Air Pollution Prevention of the Association of German Engineers and the German Institute of Standardization reanalysed the literature on O3 effects on European plant species published between 1989 and 1999. An exposure-response relationship for wild plant species and agricultural crops could be derived from 30 experiments with more than 30 species and 90 data points; the relationship for conifer and deciduous trees is based on 20 experiments with nine species and 50 data points. From these relationships maximum O3 concentrations for different risk stages are deduced, below which the vegetation type is protected on the basis of the respective criteria. Because it is assumed that the fumigation concentrations reflect the O3 concentrations at the top of the canopy, i.e. the upper surface boundary of the quasi-laminar layer if the micrometeorological big-leaf approach is applied, the application of these maximum O3 concentrations requires the transformation of O3 concentrations measured at a reference height above the canopy to the effective phytotoxic concentrations at the top of the canopy. Thus, the approach described in this paper is a synthesis of the classical concept of toxicology of air pollutants (critical concentrations) and the more toxicological relevant dose concept.

[Results of stereotactic breast biopsy in mammographically suspicious lesions]. / Ergebnisse der stereotaktischen Mammabiopsie bei mammographisch suspekten Läsionen.

PURPOSE: The object of this study was to evaluate the diagnostic accuracy of the stereotactic large core breast biopsy in the histological assessment of mammographically suspicious lesions. MATERIAL AND METHODS: In 106 patients with a mammographically suspicious lesion, 67 with a mass (55 non-palpable, 12 palpable and 39 with microcalcification stereotactic large core biopsies were performed. Samples were obtained in the prone position under local anesthesia with a 14-gauge needle and an automated high-speed gun. An average of 4.3 cores per lesion were acquired. In 68 patients (64%) an additional surgical biopsy was performed, 38 (36%) had clinical and mammographic follow-up. RESULTS: In 4 of the 106 stereotactic biopsies insufficient material for the histological examination was obtained. In the 68 core biopsies with surgical correlation there were no false-positive, but 2 false-negative results with regard to the malignancy of the lesion (sensitivity: 93.8%; specificity: 100%). The 2 false-negative results were obtained in lesions that were mammographically judged as malignant while histology of the stereotactic biopsy showed fibrosis. The stereotactic large core breast biopsy was well tolerated by all patients. No clinically significant complications occurred. CONCLUSION: The stereotactic large core breast biopsy of a mammographically suspicious lesion can be performed with a high diagnostic accuracy. A correlation of the mammographic and histological findings and a follow-up program are necessary in order to recognize false-negative results early and to avoid a delay in the diagnosis.

Digital radiography versus conventional radiography in chest imaging: diagnostic performance of a large-area silicon flat-panel detector in a clinical CT-controlled study.

OBJECTIVE: The objective of this study was to compare the diagnostic performance of a digital large-area silicon flat-panel detector with that of a conventional screen-film system in clinical chest imaging using abnormal findings documented by CT as the reference standard. SUBJECTS AND METHODS: Eighty patients (46 men and 34 women; age range,18-91 years; mean age, 63 years) who underwent CT of the chest were examined with the new digital radiography system, which is based on a 43 x 43 cm silicon flat-panel detector, and with a conventional screen-film system, which is used routinely in clinical practice. Posteroanterior and lateral radiographs were obtained. Four radiologists analyzed the digital and conventional images separately for chest abnormalities and rated the images using a five-level scale of confidence; CT was used as the reference standard. Diagnostic value was assessed using receiver operating characteristic curves for each abnormality. RESULTS: No significant differences were found between the area under the receiver operating characteristic curve of the digital and that of the conventional radiography method for almost all investigated criteria. The only exception was mediastinal abnormalities, for which the digital method provided better results than the conventional method (p < 0.05). CONCLUSION: The diagnostic performance of the new large-area silicon flat-panel detector is equivalent or superior to that of the conventional screen-film system for clinical chest imaging and can replace conventional radiography systems. This new technology offers transmission and storage possibilities inherent to digital radiology that would facilitate daily practice and reduce the initial high costs in the long-term.

The exchange of ozone between vegetation and atmosphere: micrometeorological measurement techniques and models.

The European critical levels (CLs) to protect vegetation are expressed as an accumulative exposure over a threshold of 40 ppb (nl l(-1)). In view of the fact that these chamber-derived CLs are based on ozone (O(3)) concentrations at the top of the canopy the correct application to ambient conditions presupposes the application of Soil-Vegetation-Atmosphere-Transfer (SVAT) models for quantifying trace gas exchange between phytosphere and atmosphere. Especially in the context of establishing control strategies based on flux-oriented dose-response relationships, O(3) flux measurements and O(3) exchange simulations are needed for representative ecosystems. During the last decades several micrometeorological methods for quantifying energy and trace gas exchange were developed, as well as models for the simulation of the exchange of trace gases between phytosphere and atmosphere near the ground. This paper is a synthesis of observational and modeling techniques which discusses measurement methods, assumptions, and limitations and current modeling approaches. Because stomatal resistance for trace gas exchange is parameterized as a function of water vapor or carbon dioxide (CO(2)) exchange, the most important micrometeorological techniques especially for quantifying O(3), water vapor and CO(2) flux densities are discussed. A comparison of simulated and measured O(3) flux densities shows good agreement in the mean.

Methods for estimating HIV prevalence: A comparison of extrapolation from surveys on infection rate and risk behaviour with back-calculation for the Netherlands.

OBJECTIVES: To compare HIV prevalence estimates (total number infected) by using extrapolation from surveys on infection rate and risk behaviour (EIR) in specific segments of the population and back-calculation (BC) on reported AIDS cases. To discuss potential sources of bias and error, and to identify areas for improvement of the methodology. DESIGN: Systematic comparison and epidemiological assessment of data input, underlying assumptions, and output. METHODS: Low, possibly unbiased and high estimates of HIV prevalence as of January 1996 for homo/bisexual men, injecting drug users. heterosexual men and women with multiple partners, and blood transfusion recipients and haemophiliacs were derived from surveys and continuous data collections on HIV infection rate and risk behaviour in the Netherlands between 1992 and 1996. These were compared with estimates (point and 95 % CI) by empirical Bayesian BC on AIDS cases 1982-1995. RESULTS AND CONCLUSIONS: The estimate of HIV prevalence by EIR was 13,806 with low and high estimates of 9619 and 17,700, respectively. The HIV prevalence estimate by BC was 8812 (95% CI: 7759-9867). The available data from EIR are too limited for accurate estimates of HIV prevalence. EIR estimates could be improved considerably with more precise data on prevalence of risk behaviours and HIV prevalence rate for homosexual men. More confidence can be put in the BC estimates, but these could be underestimates because of the age effect on incubation time, pre-AIDS treatment and relapse of risk behaviour. BC estimates could be improved by a better representation of the incubation time distribution (including the effect of age there-upon), better data on the effectiveness and uptake of pre-AIDS antiretroviral treatment and prophylaxis of opportunistic infections, and on the level of underreporting.

Response of a grassland ecosystem to air pollutants. VI. The chemical climate: concentrations and potential flux densities of relevant criteria pollutants.

Of the so-called criteria air pollutants, ozone (O3) and sulfur dioxide (SO2) are relevant to agriculture due to their known toxic (O3, SO2) and fertilizing (SO2) potentials. A proper entity to describe pollutant doses in dose-response relationships is the cumulative flux density absorbed by the respective receptor systems. For nutrient budgets the whole ecosystem acts as receptor; for toxicological considerations, stomatal uptake has to be considered primarily. In Central Europe, the atmospheric inputs of oxidized S (SO2, SO3(2-) and SO4(2-)) have declined from the past, and at present are generally below the nutrient requirements of agroecosystems. In contrast, the phytotoxic potential of O3 has increased during the last decade. Pollutant absorbed doses and weighted concentrations were used to describe the risk potential. It could be shown that these two differ significantly.

Degenerative change in the cervical spine and load-carrying on the head.

OBJECTIVE: To evaluate the relationship between load-carrying on the head and the development of degenerative change in the cervical spine. DESIGN AND SUBJECTS: A case-control study was performed with 35 individuals who had carried loads on their head (carriers) and 35 persons who never had carrier loads on their head (non-carriers). A scoring system was utilized for the assessment of the degenerative change in the cervical spine at the C3/C4, C4/C5, C5/C6 and C6/C7 levels on lateral cervical spine radiography. A total score was calculated by summing the scores for the single segments. RESULTS AND CONCLUSION: In 31 of the 35 (88.6%) carriers degenerative change was found in the cervical spine, but only in 8 of the 35 (22.9%) non-carriers (P < 0.01). The total score and the scores for segments C4/5, C5/C6 anc C6/C7 were significantly higher for the carriers than the non-carriers. It is concluded that the axial strain of load-carrying on the head exacerbates degenerative change in the cervical spine.

Radiological features of the visceral and skeletal involvement of hemochromatosis.

Hemochromatosis is a multisystem disorder produced by the excessive accumulation of iron in visceral organs and the musculoskeletal system. Clinically the disease may be silent, but characteristic radiological features may point to the diagnosis. The increased iron stores in the organs involved, especially in the liver and pancreas, result in an increased attenuation at unenhanced CT and an decreased signal intensity at MR imaging. Hemochromatosis arthropathy includes degenerative osteoarthritis and chondrocalcinosis. The distribution of the arthropathy is distinctive, but not unique, frequently affecting the second and third metacarpophalangeal joints of the hand.

PLATIN (plant-atmosphere interaction) II: Co-occurrence of high ambient ozone concentrations and factors limiting plant absorbed dose.

There is an ongoing debate as to which components of the ambient ozone (O3) exposure dynamics best explain adverse crop yield responses. A key issue is regarding the importance of peak versus mid-range hourly ambient O3 concentrations. While in this paper the importance of peak atmospheric O3 concentrations is not discounted, if they occur at a time when plants are conducive for uptake, the corresponding importance of more frequently occurring mid-range O3 concentrations is described. The probability of co-occurrence of high O3 concentrations and O3 uptake limiting factors is provided using coherent data sets of O3 concentration, air temperature, air humidity, mean horizontal wind velocity and global radiation measured at representative US and German air quality monitoring sites. Using the PLant-ATmosphere INteraction (PLATIN) model, the significance of the aforementioned meteorological parameters on ozone uptake is examined. In addition, the limitations of describing the O3 exposure for plants under ambient, chamberless conditions by SUM06, AOT40 or W126 exposure indices are discussed.

Description, assessment and meaning of vertical fluxes of matter within ecotopes: a systematic consideration.

Ecotopes are the structural elements of landscapes for which matter and energy balances can be derived from measurements. Vertical flux densities are the typical entities governing their structure and function. Potential flux densities in ecotopes are discussed in detail using a complex circuit diagram that differentiates between transport and reaction columnar resistors. From this the locations and methods of measurement are deduced. Determination of flux densities between troposphere and phytosphere/pedosphere is restricted to the constant flux layer, by theory and practice.

Effects of elevated CO2, nitrogen supply and tropospheric ozone on spring wheat-II. Nutrients (N, P, K, S, Ca, Mg, Fe, Mn, Zn).

CO(2) enrichment is expected to alter leaf demand for nitrogen and phosphorus in plant species with C(3) carbon dioxide fixation pathway, thus possibly causing nutrient imbalances in the tissues and disturbance of distribution and redistribution patterns within the plants. To test the influence of CO(2) enrichment and elevated tropospheric ozone in combination with different nitrogen supply, spring wheat (Tritium aestivum L. cv. Minaret) was exposed to three levels of CO(2) (361, 523, and 639 microl litre(-1), 24 h mean from sowing to final harvest), two levels of ozone (28.4 and 51.3 nl litre(-1)) and two levels of nitrogen supply (150 and 270 kg ha(-1)) in a full-factorial design in open-top field chambers. Additional fertilization experiments (120, 210, and 330 kg N ha(-1)) were carried out at low and high CO(2) levels. Macronutrients (N, P, K, S, Ca, Mg) and three micronutrients (Mn, Fe, Zn) were analysed in samples obtained at three different developmental stages: beginning of shoot elongation, anthesis, and ripening. At each harvest, plant samples were separated into different organs (green and senescent leaves, stem sections, ears, grains). According to analyses of tissue concentrations at the beginning of shoot elongation, the plants were sufficiently equipped with nutrients. Elevated ozone levels neither affected tissue concentrations nor shoot uptake of the nutrients. CO(2) and nitrogen treatments affected nutrient uptake, distribution and redistribution in a complex manner. CO(2) enrichment increased nitrogen-use efficiency and caused a lower demand for nitrogen in green tissues which was reflected in a decrease of critical nitrogen concentrations, lower leaf nitrogen concentrations and lower nitrogen pools in the leaves. Since grain nitrogen uptake during grain filling depended completely on redistribution from vegetative pools in green tissues, grain nitrogen concentrations fell considerably with severe implications for grain quality. Ca, S, Mg and Zn in green tissues were influenced by CO(2) enrichment in a similar manner to nitrogen. Phosphorus concentrations in green tissues, on the other hand, were not, or only slightly, affected by elevated CO(2). In stems, 'dilution' of all nutrients except manganese was observed, caused by the huge accumulation of water soluble carbohydrates, mainly fructans, in these tissues under CO(2) enrichment. Whole shoot uptake was either remarkably increased (K, Mn, P, Mg), nearly unaffected (N, S, Fe, Zn) or decreased (Ca) under CO(2) enrichment. Thus, nutrient cycling in plant-soil systems is expected to be altered under CO(2) enrichment.

[Pancreatic polypeptide secreting endocrine pancreas tumor associated with multiple stomach and duodenal ulcers]. / Pankreatischer Polypeptid-sezernierender endokriner Pankreastumor assoziiert mit multiplen Ulcera ventriculi et duodeni.

A 58-year-old woman presented with multiple gastroduodenal ulcera caused by a pancreatic polypeptidoma (PPoma) without hypergastrinemia or gastrin-producing tumor cells. After curative resection of the neoplasm, the clinical symptoms disappeared and the patient has now been disease-free for 6 years. We conclude that patients with non-gastrin-producing endocrine pancreatic tumors may demonstrate the clinical features of Zollinger-Ellison syndrome and should be included in the differential diagnosis of this syndrome.

The response of perennial ryegrass/white clover swards to elevated atmospheric CO2 concentrations 1. Effects on competition and species composition and interaction with N supply.

The effects of long-term carbon dioxide enrichment on competition for nutrients and light in a ryegrass/clover association were determined for simulated swards of perennial ryegrass (Lolium perenne L. cv. Parcour) and white clover (Trifolium repens L. cv. Karina), which were grown as monocultures and in three mixtures (25/75, 50/50, 75/25), according to the replacement design, at two levels of nitrogen (N) supply (no additional N and 200 kg N ha-1 ) and at season-long ambient (380 ppm) and elevated (670 ppm) CO2 concentrations, in open-top chambers. Stands were cut four times, at about monthly intervals, to a height of 5 cm. Plant material was separated into different species, fresh and dry weights were determined and the content of macroelements (N, P, K, S, Mg) in both species was measured. In addition, plant height of both species at harvest dates and during several regrowth periods was monitored. Results indicate that both species made demand on different resources and profited from growth in a mixed sward. Co2 related yield increase amounted to 16-4-2 % for white clover whereas the effect of high CO2 on ryegrass yield ranged between -33% and +9% depending on N supply, mixture and year. As a result the contribution of white clover to total yield in mixed swards was significantly enhanced by CO2 enrichment at many harvests in both N supply treatments. Without additional N supply, shoot competition for light was intensified by CO2 enrichment to the disadvantage of ryegrass, since clover petioles grew longer and ryegrass was shorter at elevated CO2 With N fertilization, no marked effect of CO2 enrichment on interspecific competition could be observed. Since clover and total yield were increased by CO2 enrichment, nutrient requirements were also increased and potassium deficiency and increased intraspecific competition of clover for K was observed in the mixtures under elevated CO2 which had the highest nutrient withdrawal. Although white clover profited much more from CO2 enrichment in both N fertilization treatments, the suppression of ryegrass in mixed swards could only be observed under low N conditions. Generally, the effect of N fertilization on competitive interference between both species was much greater than the effect of CO2 enrichment and it is suggested that the effect of elevated CO2 on the balance of species and the outcome of competition in a grass/clover sward is mainly dependent on the N status.

Effects of elevated CO2 nitrogen supply and tropospheric ozone on spring wheat. I. Growth and yield.

Spring wheat (Triticum aestivum L. cv. Minaret) was exposed to three CO(2) levels, in combination with two nitrogen fertilizer levels and two levels of tropospheric ozone, from sowing to ripening in open-top chambers. Three additional nitrogen fertilizer treatments were carried out at the lowest and the highest CO(2) level, respectively. Plants were harvested at growth stages 31, 65 and 93 and separated into up to eight fractions to gain information about biomass partitioning. CO(2) enrichment (263 microl litre(-1) above ambient levels) drastically increased biomass of organs serving as long-term carbohydrate pools. Peduncle weight increased by 92%, stem weight by 73% and flag leaf sheath weight by 59% at growth stage 65. Average increase in shoot biomass due to CO(2) enrichment amounted to 51% at growth stage 65 and 36% at final harvest. Average yield increase was 34%. Elevated nitrogen application was most effective on biomass of green tissues. Yield was increased by 30% when nitrogen application was increased from 150 to 270 kg N ha(-1). Significant interactions were observed between CO(2) enrichment and nitrogen application. Yield increase due to CO(2) ranged from 23% at 120 kg N to 47% at 330 kg N. Triticum aestivum cv. Minaret was not very responsive to ozone at 1.5 times ambient levels. 1000 grain weight was slightly decreased, which was compensated by an increased number of grains.