Relationships between uptake of [68Ga]Ga-DOTA-TATE and absorbed dose in [177Lu]Lu-DOTA-TATE therapy.

BACKGROUND: Somatostatin receptor 68Ga PET imaging is standard for evaluation of a patient's suitability for 177Lu peptide receptor radionuclide therapy of neuroendocrine tumours (NETs). The 68Ga PET serves to ensure sufficient somatostatin receptor expression, commonly evaluated qualitatively. The aim of this study is to investigate the quantitative relationships between uptake in 68Ga PET and absorbed doses in 177Lu therapy. METHOD: Eighteen patients underwent [68Ga]Ga-DOTA-TATE PET imaging within 20 weeks prior to their first cycle of [177Lu]Lu-DOTA-TATE. Absorbed doses for therapy were estimated for tumours, kidney, spleen, and normal liver parenchyma using a hybrid SPECT/CT-planar method. Gallium-68 activity concentrations were retrieved from PET images and also used to calculate SUVs and normalized SUVs, using blood and tissue for normalization. The 68Ga activity concentrations per injected activity, SUVs, and normalized SUVs were compared with 177Lu activity concentrations 1 d post-injection and 177Lu absorbed doses. For tumours, for which there was a variable number per patient, both inter- and intra-patient correlations were analysed. Furthermore, the prediction of 177Lu tumour absorbed doses based on a combination of tumour-specific 68Ga activity concentrations and group-based estimates of the effective half-lives for grade 1 and 2 NETs was explored. RESULTS: For normal organs, only spleen showed a significant correlation between the 68Ga activity concentration and 177Lu absorbed dose (r = 0.6). For tumours, significant, but moderate, correlations were obtained, with respect to both inter-patient (r = 0.7) and intra-patient (r = 0.45) analyses. The correlations to absorbed doses did not improve when using 68Ga SUVs or normalized SUVs. The relationship between activity uptakes for 68Ga PET and 177Lu SPECT was stronger, with correlation coefficients r = 0.8 for both inter- and intra-patient analyses. The 177Lu absorbed dose to tumour could be predicted from the 68Ga activity concentrations with a 95% coverage interval of - 65% to 248%. CONCLUSIONS: On a group level, a high uptake of [68Ga]Ga-DOTA-TATE is associated with high absorbed doses at 177Lu-DOTA-TATE therapy, but the relationship has a limited potential with respect to individual absorbed dose planning. Using SUV or SUV normalized to reference tissues do not improve correlations compared with using activity concentration per injected activity.

Denitrification process and suspended solids separation in deep-bed two-media down-flow filters.

A denitrification process with simultaneous suspended solids separation and denitrification was studied in pilot-scale filters. Denitrification rates for the total, upper, middle, and lower layer of the filter bed were 21.3, 79.0, 27.8, and 21.9 g (NO3+NO2)-N m-3 filter bed h-1 (g NOx-N m-3 h-1), respectively. The biofilm on the grains showed denitrification rates for not backwashed grains and grains backwashed once of 8.8 and 7.8 g NOx-N m-3 h-1, respectively, indicating a robust biofilm. Construction and operation strategies of full-scale filters were done based on the pilot-scale study results. For further optimization of the denitrification process, 1 of 60 filters in operation was chosen for a full-scale study. The denitrification rates for the total layer, upper layer, middle layers, and lower layer of the filter bed were 12.7, 15.6, 27.3, 27.9, 27.8, and 14.0 g NOx-N m-3 h-1, respectively. The rate of 27.8 g NOx-N m-3 h-1 was obtained for a middle layer in both filters. The amount of nitrogen possible to reduce in the full-scale filters was calculated to 8.8 mg N L-1 or 2403 kg N d-1. This paper presents results of denitrification rates, reaction orders, rate constants, and suspended solids separation.

Comparison of conventional and Si-photomultiplier-based PET systems for image quality and diagnostic performance.

BACKGROUND: A new generation of positron emission tomography with computed tomography (PET-CT) was recently introduced using silicon (Si) photomultiplier (PM)-based technology. Our aim was to compare the image quality and diagnostic performance of a SiPM-based PET-CT (Discovery MI; GE Healthcare, Milwaukee, WI, USA) with a time-of-flight PET-CT scanner with a conventional PM detector (Gemini TF; Philips Healthcare, Cleveland, OH, USA), including reconstruction algorithms per vendor's recommendations. METHODS: Imaging of the National Electrical Manufacturers Association IEC body phantom and 16 patients was carried out using 1.5 min/bed for the Discovery MI PET-CT and 2 min/bed for the Gemini TF PET-CT. Images were analysed for recovery coefficients for the phantom, signal-to-noise ratio in the liver, standardized uptake values (SUV) in lesions, number of lesions and metabolic TNM classifications in patients. RESULTS: In phantom, the correct (> 90%) activity level was measured for spheres ≥17 mm for Discovery MI, whereas the Gemini TF reached a correct measured activity level for the 37-mm sphere. In patient studies, metabolic TNM classification was worse using images obtained from the Discovery MI compared those obtained from the Gemini TF in 4 of 15 patients. A trend toward more malignant, inflammatory and unclear lesions was found using images acquired with the Discovery MI compared with the Gemini TF, but this was not statistically significant. Lesion-to-blood-pool SUV ratios were significantly higher in images from the Discovery MI compared with the Gemini TF for lesions smaller than 1 cm (p < 0.001), but this was not the case for larger lesions (p = 0.053). The signal-to-noise ratio in the liver was similar between platforms (p = 0.52). Also, shorter acquisition times were possible using the Discovery MI, with preserved signal-to-noise ratio in the liver. CONCLUSIONS: Image quality was better with Discovery MI compared to conventional Gemini TF. Although no gold standard was available, the results indicate that the new PET-CT generation will provide potentially better diagnostic performance.

DENTAL LESIONS IN THE LOWLAND TAPIR (TAPIRUS TERRESTRIS).

Dental ailments, mandibular swelling, and dentoalveolar abscesses are common in tapirs, but knowledge about prevalence or etiology of these lesions in the Tapiridae family in general, and in lowland tapirs (Tapirus terrestris) in particular, is scarce. A recent study identified resorptive lesions of unknown etiology as a common problem in the Malayan tapir (Tapirus indicus). In order to investigate the type and prevalence of dental lesions occurring in lowland tapirs, and to compare these with findings with the Malayan tapir, skulls and teeth from 46 deceased lowland tapirs were visually and radiographically examined. The specimens were divided into subpopulations according to age (juveniles, young adults, adults) and origin (free-range or captive). Dental lesions were identified in 24% (11/46) of the study population. The most common pathologic findings were complicated dental fractures with associated periapical reaction (15%) and periapical reactions of various degrees without associated detectable dental pathology (13%). All these lesions likely originated from dental trauma. As in Malayan tapirs, juveniles had significantly fewer lesions than adults. This study shows that dental lesions present frequent problems for lowland tapirs, occurring both in captive and in free-ranging individuals, and indicates that increasing age should be considered a risk factor for the development of these lesions. Notably, the predominant dental problems in lowland tapirs and Malayan tapirs are not the same.

The ordinary work environment increases symptoms from eyes and airways in mild steel welders.

PURPOSE: We aimed to follow diary-registered symptoms from eyes and airways in mild steel welders and relate them to different exposure measures. Furthermore, we would clarify the influence of possible effect modifiers. METHODS: Non-smoking welders with (N = 74) and without (N = 32) work-related symptoms the last month were enroled. Symptoms and work tasks each day for three two-week periods during 1 year were obtained. Respirable dust (RD) was measured 1 day each period for each worker. The personal daily exposure was assessed as: (1) days at work, (2) welding time and (3) estimates of RD from welding and grinding, calculated from diary entries and measurements. RESULTS: Only 9.2 % of the particle measurements exceed the Swedish occupational exposure limit (OEL; 5 mg/m(3)). Days at work increased the risk of symptoms studied: eyes: 1.79 (1.46-2.19), nasal: 2.16 (1.81-2.58), dry cough: 1.50 (1.23-1.82) and wheezing and/or dyspnoea: 1.27 (1.03-1.56; odds ratio, 95 % confidence interval). No clear dose-response relationships were found for the other exposure estimates. Eye symptoms increased by number of years welding. Nasal symptoms and dry cough increased having forced expiratory volume in first second below median at baseline. Wheezing and/or dyspnoea increased in winter, by number of years welding, having a negative standard skin-prick test and having a vital capacity above median at baseline. CONCLUSION: The current Swedish OEL may not protect welders against eye and airway symptoms. The results add to the evidence that welders should be offered regular medical surveillance from early in the career.

Adverse events in Public Dental Service in a Swedish county--a survey of reported cases over two years.

Adverse events cause suffering and increased costs in health care. The main way of registering adverse event is through dental personnel's reports, but reports from patients can also contribute to the knowledge of such occurrences. This study aimed to analyse the adverse events reported by dental personnel and patients in public dental service (PDS) in a Swedish county. The PDS has an electronic system for reporting and processing adverse events and, in addition, patients can report shortcomings, as regards to reception and treatment, to a patient committee or to an insurance company. The study material consisted of all adverse events reported in 2010 and 2011, including 273 events reported by dental personnel, 53 events reported by patients to the insurance company and 53 events reported by patients to the patient committee. Data concerning patients' age and gender, the nature, severity and cause of the event and the dental personnel's age gender and profession were collected and analysed. Furthermore the records describing the dental personnel's reports from 2011 were studied to investigate if the event had been documented and the patient informed. Age groups 0 to 9 and 20 to 39 years were underrepresented while those between the ages 10 to 19 and 60 to 69 years were overrepresented in dental personnel's reports. Among young patients delayed diagnosis and therapy dominated and among patients over 20 years the most frequent reports dealt with inadequate treatments, especially endodontic treatments. In 29% of the events there was no documentation of the adverse event in the records and 49% of cases had no report about patient information. The majority of the reports from dental personnel were made by dentists (69%). Reporting adverse events can be seen as a reactive way of working with patient safety, but knowledge about frequencies and causes of incidents is the basis of proactive patient safety work.

Brain imaging and human nutrition: which measures to use in intervention studies?

The present review describes brain imaging technologies that can be used to assess the effects of nutritional interventions in human subjects. Specifically, we summarise the biological relevance of their outcome measures, practical use and feasibility, and recommended use in short- and long-term nutritional studies. The brain imaging technologies described consist of MRI, including diffusion tensor imaging, magnetic resonance spectroscopy and functional MRI, as well as electroencephalography/magnetoencephalography, near-IR spectroscopy, positron emission tomography and single-photon emission computerised tomography. In nutritional interventions and across the lifespan, brain imaging can detect macro- and microstructural, functional, electrophysiological and metabolic changes linked to broader functional outcomes, such as cognition. Imaging markers can be considered as specific for one or several brain processes and as surrogate instrumental endpoints that may provide sensitive measures of short- and long-term effects. For the majority of imaging measures, little information is available regarding their correlation with functional endpoints in healthy subjects; therefore, imaging markers generally cannot replace clinical endpoints that reflect the overall capacity of the brain to behaviourally respond to specific situations and stimuli. The principal added value of brain imaging measures for human nutritional intervention studies is their ability to provide unique in vivo information on the working mechanism of an intervention in hypothesis-driven research. Selection of brain imaging techniques and target markers within a given technique should mainly depend on the hypothesis regarding the mechanism of action of the intervention, level (structural, metabolic or functional) and anticipated timescale of the intervention's effects, target population, availability and costs of the techniques.

Is acculturation associated with physical activity among female immigrants in Sweden?

BACKGROUND: Immigrant women in Sweden have lower levels of leisure time physical activity (LTPA) than Swedish-born women. The reasons are unclear, although acculturation has been suggested to play a role. METHODS: We used a cross-sectional study design to investigate the association between LTPA and two indicators of acculturation: (i) language proficiency (ability to understand news reports on the radio and television) and (ii) age at the time of migration, and if there existed a modifying effect on these hypothesized associations. The study sample consisted of 1651 women, aged 18-65, living in Sweden and born in Finland, Chile or Iraq. A postal questionnaire (translated into the women's native language) was used to collect the variables. The International Physical Activity Questionnaire was used to assess LTPA. Data were collected in 2002-05 and analyzed in 2009-10. A partial-proportional odds model was used for the analysis. RESULTS: Increased language proficiency was associated with increased LTPA [odds ratio (OR) = 2.31, 95% confidence interval (CI) = 1.57-3.41]. Country of birth modified the association. Furthermore, younger age at migration was associated with increased LTPA (OR = 1.44, 95% CI = 1.01-2.03). CONCLUSIONS: Increased language proficiency has the potential to be an important health-promoting factor among immigrant women.

Preterm birth and unintentional injuries: risks to children, adolescents and young adults show no consistent pattern.

AIM: Preterm birth is associated with a number of physical and mental health issues. The aim of this study was to find out whether there was also any association between individuals born preterm in Sweden between 1984 and 2006 and the risk of unintentional injuries during childhood, adolescence and young adulthood. METHODS: The study followed 2 297 134 individuals, including 5.9% born preterm, from 1985 to 2007 for unintentional injuries leading to hospitalization or death (n = 244 021). The males and females were divided into four age groups: 1-5 years, 6-12 years, 13-18 years and 19-23 years. Hazard ratios were calculated for falls, transport injuries and other injuries. RESULTS: After adjusting for a comprehensive set of covariates, some of the preterm subgroups demonstrated slightly increased risks of unintentional injuries, while others showed slightly decreased risks. However, most of the estimates were borderline or non-significant in both males and females. In addition, the absolute risk differences between individuals born preterm and full term were small. CONCLUSION: Despite the association between preterm birth and a variety of physical and mental health consequences, this study shows that there is no consistent risk pattern between preterm birth and unintentional injuries in childhood, adolescence and young adulthood.

Dietary factors and low-grade inflammation in relation to overweight and obesity.

Low-grade inflammation is a characteristic of the obese state, and adipose tissue releases many inflammatory mediators. The source of these mediators within adipose tissue is not clear, but infiltrating macrophages seem to be especially important, although adipocytes themselves play a role. Obese people have higher circulating concentrations of many inflammatory markers than lean people do, and these are believed to play a role in causing insulin resistance and other metabolic disturbances. Blood concentrations of inflammatory markers are lowered following weight loss. In the hours following the consumption of a meal, there is an elevation in the concentrations of inflammatory mediators in the bloodstream, which is exaggerated in obese subjects and in type 2 diabetics. Both high-glucose and high-fat meals may induce postprandial inflammation, and this is exaggerated by a high meal content of advanced glycation end products (AGE) and partly ablated by inclusion of certain antioxidants or antioxidant-containing foods within the meal. Healthy eating patterns are associated with lower circulating concentrations of inflammatory markers. Among the components of a healthy diet, whole grains, vegetables and fruits, and fish are all associated with lower inflammation. AGE are associated with enhanced oxidative stress and inflammation. SFA and trans-MUFA are pro-inflammatory, while PUFA, especially long-chain n-3 PUFA, are anti-inflammatory. Hyperglycaemia induces both postprandial and chronic low-grade inflammation. Vitamin C, vitamin E and carotenoids decrease the circulating concentrations of inflammatory markers. Potential mechanisms are described and research gaps, which limit our understanding of the interaction between diet and postprandial and chronic low-grade inflammation, are identified.

Gene expression analysis in induced sputum from welders with and without airway-related symptoms.

PURPOSE: To identify changes in gene expression in the airways among welders, with and without lower airway symptoms, working in black steel. METHODS: Included were 25 male, non-smoking welders. Each welder was sampled twice; before exposure (after vacation), and after 1 month of exposure. From the welders (14 symptomatic, of whom 7 had asthma-like symptoms), RNA from induced sputum was obtained for gene expression analysis. Messenger RNA from a subset of the samples (n = 7) was analysed with microarray technology to identify genes of interest. These genes were further analysed using quantitative PCR (qPCR; n = 22). RESULTS: By comparing samples before and after exposure, the microarray analysis resulted in several functional annotation clusters: the one with the highest enrichment score contained "response to wounding", "inflammatory response" and "defence response". Seven genes were analysed by qPCR: granulocyte colony-stimulating factor 3 receptor (CSF3R), superoxide dismutase 2, interleukin 8, glutathione S-transferase pi 1, tumour necrosis factor alpha-induced protein 6 (TNFAIP6), interleukin 1 receptor type II and matrix metallopeptidase 25 (MMP25). Increased levels of CSF3R, TNFAIP6 and MMP25 were indicated among asthmatic subjects compared to non-symptomatic subjects, although the differences did not reach significance. CONCLUSIONS: Workers' exposure to welding fumes changed gene expression in the lower airways in genes involved in inflammatory and defence response. Thus, microarray and qPCR technique can demonstrate markers of exposure to welding fumes and possible disease-related markers. However, further studies are needed to verify genes involved and to further characterise the mechanism for welding fumes-associated lower airway symptoms.

N-nitrosamines in the southern Swedish rubber industries - exposure, health effects, and immunologic markers.

OBJECTIVES: The aim of this study was twofold: (i) to evaluate the air levels of N-nitrosamines in the Swedish rubber industry and (ii) to estimate the risk of symptoms and changed levels of immunologic markers in relation to these levels. METHODS: Using adsorption tubes, we collected samples of N-nitrosamines in the breathing zone of 96 rubber workers and analyzed them with liquid chromatography tandem mass spectrometry. Of these 96 workers, 66 were included in a medical examination and blood analysis together with an additional 106 rubber workers and 118 unexposed subjects. Medical and occupational histories were obtained in structured interviews, symptoms were recorded and immunologic markers analyzed in blood. RESULTS: The sum of N-nitrosamines ranged from less than the limit of detection to 36 microg/m (3)and differed with the vulcanization (ie, curing process) method used. Workers vulcanizing with a salt bath had the highest levels (median 4.2 microg/m (3)). Compared to the unexposed subjects, the rubber workers had an increased risk of nosebleeds, eye and throat symptoms, hoarseness, cough, nausea, headache, and changed levels of eosinophils and total immunoglobulin G (IgG). However, we found no clear exposure-response relationship with the symptoms or the immunologic markers studied. CONCLUSIONS: High levels of N-nitrosamines were found and must be lowered considerably in order to decrease the risk of cancer. There is a need for an occupational exposure limit for N-nitrosamines in Sweden. The lack of exposure-response relationships with the subacute symptoms examined in this study may be due to a healthy-worker selection or to the possibility that the symptoms are caused by an exposure not co-varying with N-nitrosamines.

Gene expression in nasal lavage from hairdressers exposed to persulphate.

OBJECTIVES: Many hairdressers experience work-related symptoms from the airways caused by bleaching powder. This contains persulphates, which could be irritating to the mucous membrane and also may evoke an allergic reaction. However, specific IgE antibodies are difficult to detect. We found earlier that hairdressers with work-related bleaching powder-associated nasal symptoms reacted to persulphate, but that atopics also did and that the mechanism appeared to be similar in the two groups. In this study, we analysed gene expression of cytokines in the nose in order to further investigate the mechanism for work-related bleaching powder-associated nasal symptoms. METHODS: The study subjects belonged to either hairdressers with work-related bleaching powder-associated nasal symptoms (S; n = 6), hairdressers without work-related bleaching powder-associated symptoms (WS; n = 7) or atopics (A; n = 6). Nasal lavage was performed before and during (up to 4 h after the last challenge) provocation with potassium persulphate. Expression of two genes involved in allergic inflammation [interleukin 5 (IL5) and IL13] and one involved in cell-mediated immunity (interferon-gamma; IFNG) were analysed in nasal lavage with quantitative PCR. RESULTS: The change of IL5 in the S group differed when compared to the WS group (P = 0.0051), in the A group when compared to the WS group (P = 0.014), but not in the S group when compared to the A group (P = 0.82). The change of IL13 in the A group differed when compared to the S (P = 0.041) and WS (P = 0.014) groups, but no difference was noticed between the S and WS groups (P = 0.30). The relative level of IFNG increased from before challenge to during challenge in the S group (P = 0.031). CONCLUSIONS: Symptomatic hairdressers showed increased expression of IL5 and IFNG, but not IL13, during challenge. Hairdressers without work-related bleaching powder-associated nasal symptoms showed no markedly changed reaction. Atopics showed increased expression of IL5 and IL13. Thus, this may indicate a difference in the mechanism of symptoms between symptomatic hairdressers and atopics. However, due to the low number of participants, further studies are needed to elucidate the mechanism for persulphate-associated nasal symptoms.

Lung function in relation to 2-thiothiazolidine-4-carboxylic acid and genetic effect modification among rubber workers in Sweden.

OBJECTIVE: What is the risk of impaired lung function in contemporary Swedish rubber workers and are there modifying effects of genetic variants? METHODS: Included in the study were 159 rubber exposed and 118 not-rubber exposed workers. Lung function was analyzed as forced vital capacity percent of predicted and forced expiratory volume in 1 second percent of predicted. Levels of 2-thiothiazolidine-4-carboxylic acid (a marker of carbon disulfide and vulcanization fumes) was assessed with liquid chromatography tandem mass spectrometry. Polymorphisms in glutathione-related genes were analyzed by Taqman-based allelic discrimination and ordinary polymerase chain reaction. RESULTS: There was an association between increasing levels of 2-thiothiazolidine-4-carboxylic acid and impaired lung function among exposed workers. The association was modified by glutathione S-transferase alpha 1 (GSTA1)-52 and GSTP1-114. GSTM1 had an influence on lung function among unexposed workers. CONCLUSIONS: There may be a risk of impaired lung function in contemporary rubber workers. Gene-modifying effects may be considered in risk assessments.

Levels of 1-hydroxypyrene, symptoms and immunologic markers in vulcanization workers in the southern Sweden rubber industries.

OBJECTIVES: The aim of this study was to determine urinary 1-hydroxypyrene (1-HP) levels in contemporary Swedish vulcanization workers and in controls. These levels were used as an index substance for vulcanization fumes, as well as a biomarker for polycyclic aromatic hydrocarbons (PAHs). The risk of symptoms and changed levels of immunologic markers were investigated in relation to the 1-HP levels. METHODS: Included in the study were 163 exposed workers and 106 controls. Medical and occupational histories were obtained by structured interviews. Symptoms were recorded and immunologic markers analysed in blood by routine analysis methods. Levels of 1-HP were determined by liquid chromatography and fluorescence detection. RESULTS: The highest levels of 1-HP were found among exposed workers using injection and compression vulcanization and lower levels were found among exposed workers vulcanizing with salt bath, hot air, microwaves or fluid-bed. Compared to controls, exposed workers had increased risks of eye symptoms, nosebleeds, burning and dry throat, hoarseness, severe dry cough, nausea and headache. Furthermore, exposed workers had elevated levels of neutrophils and total IgG (immunoglobulin subclass G). However, only for severe dry cough an evident exposure-response relationship with urinary 1-HP levels was found. CONCLUSIONS: This work clearly shows increased levels of urinary 1-HP in Swedish vulcanization workers. Furthermore, it demonstrates an increased risk of several symptoms and elevated levels of some immunologic markers in these workers. However, no obvious exposure-response relationships were found.

Influence of glutathione-related genes on symptoms and immunologic markers among vulcanization workers in the southern Sweden rubber industries.

OBJECTIVE: The aim was to elucidate the role of genetic variants on symptoms of the eyes and airways, headache and nausea, as well as on immunologic markers, among vulcanization workers in the contemporary Swedish rubber industry. Polymorphisms in genes, which are involved in the defense against reactive oxygen species and metabolism of toxic substances present in the vulcanization fumes, were analyzed. METHODS: One hundred and forty-five exposed and 117 unexposed workers were included in the study. Medical and occupational histories were obtained in structured interviews. Symptoms were recorded and immunologic markers analyzed in blood. Polymorphisms in glutathione-related genes (glutamate cysteine ligase catalytic subunit (GCLC)-129, glutamate cysteine ligase modifier subunit (GCLM)-588, glutathione S-transferase alpha 1 (GSTA1)-52, GSTM1*O, GSTP1-105, GSTP1-114, and GSTT1*O) were analyzed by Taqman-based allelic discrimination and ordinary PCR. RESULTS: A protective effect of GSTA1-52 (G/A + A/A) genotype on symptoms and immunologic cells, in particular among exposed workers, was suggested. Exposed workers with GSTT1*O had increased risk of nosebleed compared to exposed workers with GSTT1*1. Exposed workers with GSTP1-105 (ile/val + val/val) had decreased levels of total immunoglobulin E (IgE) compared to exposed workers with GSTP1-105 ile/ile. GCLC-129 variant genotype demonstrated increased levels of immunologic cells among exposed workers, although statistical significance was not reached. CONCLUSION: Our data indicate that hereditary factors influence the susceptibility to symptoms and the immunologic response of workers in the rubber industry.

Symptoms and immunologic markers among vulcanization workers in rubber industries in southern Sweden.

OBJECTIVES: The aim of this study was to estimate the risk of symptoms and the possible derangement of levels of immunologic markers for contemporary Swedish rubber workers. Furthermore, the relation between exposure and these biomarkers of response was examined using urinary levels of 2-thiothiazolidine-4-carboxylic acid (TTCA), which reflect the exposure. METHODS: Included in the study were 166 exposed workers and 117 controls. Medical and occupational histories were obtained in structured interviews. Symptoms were recorded, and immunologic markers were analyzed in blood. Urinary levels of TTCA were determined by liquid chromatography tandem mass spectrometry. RESULTS: Compared with the controls, the exposed workers had increased risks of eye symptoms [odds ratio (OR) 3.0], nose bleeds (OR 4.0), burning and dry throat (OR 3.0), hoarseness (OR 2.4), severe dry cough (OR 3.8), nausea (OR 4.3), and headache (OR 2.5). When the exposed workers were divided into three groups according to the TTCA levels, the highest risks were observed among the exposed workers with intermediate TTCA levels. Furthermore, the exposed workers in all of the TTCA subgroups had elevated concentrations of total immunoglobulin G when compared with the controls. Elevated concentrations of leukocytes, neutrophils, and eosinophils were observed in the group with high TTCA levels. CONCLUSIONS: This work shows an increased risk of several symptoms and elevated levels of some immunologic markers among exposed workers in Swedish rubber industries. In addition, relationships between urinary levels of TTCA and some biomarkers of response were reported.

Levels of 2-thiothiazolidine-4-carboxylic acid (TTCA) and effect modification of polymorphisms of glutathione-related genes in vulcanization workers in the southern Sweden rubber industries.

OBJECTIVES: Workers in the rubber industry are exposed to a complex mixture of hazardous substances and have increased risk of developing several diseases. However, there is no up to date survey examining the exposure in the Swedish rubber industry. One of the toxic compounds in the industry is carbon disulfide (CS(2)), which is biotransformed to 2-thiothiazolidine-4-carboxylic acid (TTCA). TTCA is used as a biomarker of CS(2) exposure, but there seem to exist inter- and intraindividual variability; which could partly be due to genetic variation. The aim of the study was to determine TTCA levels and the modifying effects of glutathione-related genes in a group of Swedish rubber workers. METHODS: Urine was collected from both exposed workers and controls during the last 4 h of the work shift. The level of TTCA in urine was analyzed by liquid chromatograpy tandem mass spectrometry. Genotyping of the single nucleotide polymorphisms GCLC-129, GCLM-588, GSTA1-52, GSTP1-105 and GSTP1-114 and deletions of GSTM1 and GSTT1 were performed with real-time PCR or ordinary PCR and subsequent agarose electrophoresis. RESULTS: The highest levels of TTCA were found among workers curing with salt bath, hot air, microwaves or fluid-bed, and lower levels were found among workers curing with injection and compression molding. Furthermore, with respect to GSTM1 and GSTT1 there were statistically significant differences in TTCA-levels between genotypes among exposed workers but not among controls. The other five polymorphisms had no impact on the TTCA levels. CONCLUSIONS: The present study demonstrates relatively high levels of TTCA in urine from Swedish rubber workers. Polymorphisms in GSTM1 and GSTT1 modify the levels.

Evaluation of accuracy in activity calculations for the conjugate view method from Monte Carlo simulated scintillation camera images using experimental data in an anthropomorphic phantom.

UNLABELLED: Activity determination from scintillation camera images using the conjugate view method may be inaccurate because of variation in scattered radiation from adjacent organs and activity from overlapping tissues. The aim of this study was to simulate patient scintillation camera images and from these evaluate the accuracy of 2 correction methods. The contribution from overlapping tissue activity was also calculated for some organs. METHODS: Biokinetic data for (99m)Tc-sestamibi obtained in rats was used as input to simulate scintillation camera images with a voxel-based computer phantom using the Monte Carlo method. The organ activity was calculated using the conjugate view method with either the effective attenuation coefficient method or scatter correction using the triple-energy window (TEW) method combined with attenuation correction with a transmission factor image. Images were simulated with activity in organs one by one to evaluate the accuracy of the 2 correction methods and to evaluate the activity contribution from activity in adjacent or overlapping tissues. To allow comparison with the clinical situation, the total activity distribution from the animal study was used to simulate scintillation camera images at different points in time and the calculated activity was compared with both the input data and some patient data from the literature. RESULTS: The combination of scatter and attenuation correction gave the most accurate calculated activity, +/-10% of the true activity from the images with activity in one organ at a time. In the images similar to the clinical situation, the kidney activity was overestimated up to a factor of 34, mainly because of excretion of activity through the intestines. CONCLUSION: The scatter correction using the TEW method in combination with attenuation correction with the measured transmission factor resulted in the most accurate activity determination of the methods used. This study also shows that organ activity data calculated from scintillation camera images may be overestimated by >90% because of activity in overlapping tissues.

A school-based intervention to promote dietary change.

PURPOSE: This study examined the effect of 2 school-based interventions on adolescents' consumption and knowledge of fish with the hypothesis that home economics education would enhance the effect of modifications in the school canteen. The school lunch intervention (SL) focused on changes in the school canteen, and the school lunch + home economics intervention (SL + HE) in addition consisted of changes in the home economics syllabus. Pupils in the 8th grade (n = 228) from 3 schools in Göteborg, Sweden, participated (control, n = 83; SL group, n = 58; SL + HE group, n = 87). METHODS: A controlled design was used in which behavior and knowledge were assessed before and after the intervention. In contrast to much previous research of this type, measurement of behavior was based primarily on direct observation as opposed to self-reported intakes. Behavior (fish consumption) was measured individually by structured observations in the school canteen 5 times (once a week) when fish was served. Nutritional knowledge was measured by means of 10 items in a questionnaire. To analyze changes in behavior, a nonparametric statistical method assessing systematic change in paired ordered categoric variables was used. RESULTS: At follow-up evaluation, consumption had increased significantly in the SL + HE group, a change that also differed from the control group. In addition, significant positive changes in knowledge were observed in both intervention groups, but not in controls. CONCLUSIONS: The results suggest that dietary change was achieved by modifying conditions in the school canteen together with changing the home economics syllabus. This study shows the importance of the school in the promotion of dietary change among adolescents.