Closed vs open surgical exposure of palatally displaced canines: surgery time, postoperative complications, and patients' perceptions: a multicentre, randomized, controlled trial.

Background: Closed and open surgical techniques are two different main approaches to surgical exposure of palatally displaced canines (PDCs). Because there is insufficient evidence to support one technique over the other, there is a need for randomized controlled trials. Objectives: To compare surgery time, complications and patients' perceptions between closed and open surgical techniques in PDCs. Trial design: The trial was a multicentre, randomized, controlled trial with two parallel groups randomly allocated in a 1:1 ratio. Material and methods: Study participants were 119 consecutive patients from 3 orthodontic centres, with PDCs planned for surgical exposure, randomly allocated according to a computer-generated randomization list, using concealed allocation. Full-thickness mucoperiosteal flap was raised, and bone covering the canine was removed in both interventions. In closed exposure, an attachment with a chain was bonded to the canine and the flap was sutured back with the chain penetrating the mucosa. In open exposure, a window of tissue around the tooth was removed and glass ionomer cement placed on the canine crown, to prevent gingival overgrowth during spontaneous eruption. Patient perceptions were assessed with two questionnaires, for the evening on the day of operation and 7 days post-surgery. Blinding: It was not possible to blind either patients or care providers to the interventions. The outcome assessors were blinded and were unaware of patients' intervention group. Results: Seventy-five girls and 44 boys, mean age 13.4 years (SD 1.46) participated in the study and got either of the interventions (closed exposure, n = 60; open exposure, n = 59). Surgery time did not differ significantly between the interventions. Complications though were more severe in bilateral cases and the patients experienced more pain and impairment in the open group. Conclusion: There were no statistically significant differences regarding surgery time between the groups. Postoperative complications were similar between the groups in unilateral PDCs, but more common in the open group in bilateral cases. More patients in the open group experienced pain and impairment compared to the closed group. Trial registration: Trial registration: ClinicalTrials.gov, ID: NCT02186548 and Researchweb.org, ID: 127201.

A potential anti-tumor effect of leukotriene C4 through the induction of 15-hydroxyprostaglandin dehydrogenase expression in colon cancer cells.

Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide. Cyclooxygenase-2, which plays a key role in the biosynthesis of prostaglandin E2 (PGE2), is often up-regulated in CRC and in other types of cancer. PGE2 induces angiogenesis and tumor cell survival, proliferation and migration. The tumor suppressor 15-hydroxyprostaglandin dehydrogenase (15-PGDH) is a key enzyme in PGE2 catabolism, converting it into its inactive metabolite 15-keto-PGE2, and is often down-regulated in cancer. Interestingly, CRC patients expressing high levels of the cysteinyl leukotriene 2 (CysLT2) receptor have a good prognosis; therefore, we investigated a potential link between CysLT2 signaling and the tumor suppressor 15-PGDH in colon cancer cells.We observed a significant up-regulation of 15-PGDH after treatment with LTC4, a CysLT2 ligand, in colon cancer cells at both the mRNA and protein levels, which could be reduced by a CysLT2 antagonist or a JNK inhibitor. LTC4 induced 15-PGDH promoter activity via JNK/AP-1 phosphorylation. Furthermore, we also observed that LTC4, via the CysLT2/JNK signaling pathway, increased the expression of the differentiation markers sucrase-isomaltase and mucin-2 in colon cancer cells and that down-regulation of 15-PGDH totally abolished the observed increase in these markers.In conclusion, the restoration of 15-PGDH expression through CysLT2 signaling promotes the differentiation of colon cancer cells, indicating an anti-tumor effect of CysLT2 signaling.

FosB transcription factor regulates COX-2 expression in colorectal cancer cells without affecting PGE2 expression.

The expression levels of cyclooxygenase (COX)-2 and the prostaglandin E2 (PGE2) content have been associated with poor prognosis in patients with colorectal cancer (CRC). There is a strong correlation between COX-2 expression and PGE2 production in tissues from CRC patients, suggesting an important role for COX-2 on the regulation of PGE2 production. Previous studies by the present authors, where CRC patients were divided into high- or low-COX-2 expressing tumors, displayed important differences in the expression levels of several transcription factors involved in carcinogenesis. Among them, FBJ murine osteosarcoma viral oncogene homolog B (FosB), which is a member of the activator protein-1 complex, was the highest upregulated transcription factor in patients with high expression levels of COX-2. The present study aimed to investigate the role of FosB on the COX-2/PGE2 axis in CRC cells with high COX-2 expression levels. Interference RNA technology was used to knockdown FosB expression in HCA-7 cells, and 72 h later the messenger (m)RNA expression levels of COX-1 and COX-2, as well as the PGE2 content, were measured. The results indicated that FosB knockdown decreased the expression levels of COX-2 but did not affect the PGE2 content or the mRNA expression levels of COX-1. The present findings suggest an important role for FosB on the regulation of COX-2 expression, but no effect on the regulation of the PGE2 levels. In addition, the present results imply independent regulatory mechanisms for COX-2 expression and PGE2 content.

Determinants of personal exposure to some carcinogenic substances and nitrogen dioxide among the general population in five Swedish cities.

Environmental levels of airborne carcinogenic and related substances are comparatively better known than individual exposure and its determinants. We report on a personal monitoring program involving five Swedish urban populations. The aim of the program was to investigate personal exposure to benzene, 1,3-butadiene, formaldehyde, and nitrogen dioxide (NO2). The measurements were performed among 40 inhabitants during seven consecutive days, in one urban area each year, during 2000-2008. The estimated population exposure levels were 1.95 µg/m(3) for benzene, 0.56 µg/m(3) for 1,3-butadiene, 19.4 µg/m(3) for formaldehyde, and 14.1 µg/m(3) for NO2. Statistical analysis using a mixed-effects model revealed that time spent in traffic and time outdoors contributed to benzene and 1,3- butadiene exposure. For benzene, refueling a car was an additional determinant influencing the exposure level. Smoking or environmental tobacco smoke were significant determinants of exposure to NO2, benzene, and 1,3-butadiene. Those with a gas stove had higher NO2 exposure. Living in a single-family house increased the exposure to formaldehyde significantly. In a variance component model, the between-subject variance dominated for 1,3-butadiene and formaldehyde, whereas the between-city variance dominated for NO2. For benzene, the between-subject and between-cities variances were similar.

Lung function in volunteers before and after exposure to trichloramine in indoor pool environments and asthma in a cohort of pool workers.

OBJECTIVES: Exposure to trichloramine (NCl(3)) in indoor swimming-pool environments is known to cause mucous membrane irritation, but if it gives rise to changes in lung function or asthma in adults is not known. (1) We determined lung function in volunteers before and after exposure to indoor pool environments. (2) We studied the occurrence of respiratory symptoms and asthma in a cohort of pool workers. DESIGN/METHODS/PARTICIPANTS: (1) We studied two groups of volunteers, 37 previously non-exposed healthy persons and 14 pool workers, who performed exercise for 2 h in an indoor pool environment. NCl(3) in air was measured during pool exposures and in 10 other pool environments. Filtered air exposures were used as controls. Lung function and biomarkers of pulmonary epithelial integrity were measured before and after exposure. (2) We mailed a questionnaire to 1741 persons who indicated in the Swedish census 1990 that they worked at indoor swimming-pools. RESULTS: (1) In previously non-exposed volunteers, statistically significant decreases in FEV(1) (forced expiratory volume) and FEV(%) (p=0.01 and 0.05, respectively) were found after exposure to pool air (0.23 mg/m(3) of NCl(3)). In pool workers, a statistically significant decrease in FEV(%) (p=0.003) was seen (but no significant change of FEV(1))(.) In the 10 other pool environments the median NCl(3) concentration was 0.18 mg/m(3). (2) Our nested case/control study in pool workers found an OR for asthma of 2.31 (95% CI 0.79 to 6.74) among those with the highest exposure. Exposure-related acute mucous membrane and respiratory symptoms were also found. CONCLUSIONS: This is the first study in adults showing statistically significant decreases in lung function after exposure to NCl(3). An increased OR for asthma among highly exposed pool workers did not reach statistical significance, but the combined evidence supports the notion that current workroom exposures may contribute to asthma development. Further research on sensitive groups is warranted.

Dental behaviour management problems: the role of child personal characteristics.

AIM: This study aimed to investigate the role of dental fear (DF) and other personal characteristics in relation to dental behaviour management problems (DBMP). DESIGN: A study group of 230 patients (7.5-19 years old; 118 girls), referred because of DBMP, was compared to a reference group of 248 same-aged patients (142 girls) in ordinary dental care. Patients and their parents independently filled in questionnaires including measures of fear and anxiety, behavioural symptoms, temperamental reactivity, and emotion regulation. RESULTS: Study group patients referred because of DBMP differed from the reference group in all investigated aspects of personal characteristics. In the multivariate analyses, DF was the only variable with consistent discriminatory capacity through all age and gender subgroups. Aspects of anxiety, temperament, and behavioural symptoms contributed, but differently for different subgroups and at different levels of dental fear. CONCLUSIONS: Among older children and adolescents, DF deserves to be re-established as the single most important discriminating variable for DBMP at clearly lower scores than commonly used. Further research should focus on the different patterns of DBMP development, considering various personal characteristics that may trigger, maintain, or exacerbate young patients' vulnerability to DF and DBMP.

Field validation of the Ogawa diffusive sampler for NO2 and NOx in a cold climate.

A small-scale field trial in Umeå, Sweden with Ogawa samplers and a chemiluminescence instrument indicated that the NO(2) concentration was underestimated with respect to the reference monitor, if calculated according to the manufacturer's Ogawa sampling protocol. By co-locating Ogawa samplers and reference monitors at six sites in two Swedish cities, uptake rates were determined for NO(2) and NO(x) better applicable to the Swedish conditions and climate. The concentrations of NO(2) and NO(x) calculated according to the instruction manual of the sampler and using the field-determined uptake rates were compared with values derived from chemiluminescence monitors for each week over which samples were taken. When calculated according to the manufacturer's suggested protocol, the Ogawa sampler underestimated the NO(2) concentrations by 9.1% on average for all samples (N = 53), with respect to the reference monitor. In contrast, NO(x) concentrations were overestimated by a mean value of 15% for all samples (N = 45). By using the field determined uptake rates for the calculation of NO(2) and NO(x) a better estimation of the concentrations was obtained. The ratio between concentrations determined with the Ogawa samplers and chemiluminescence monitors was then 1.02 for all measurements of NO(2) and 1.00 for NO(x). Precision, expressed as the mean coefficient of variation, was 6.4% for six, 6-replicate measurements of NO(2) and 3.7% for five, 6-replicate measurements of NO(x).

Possible predictors of discontinuation of specialized dental treatment among children and adolescents with dental behaviour management problems.

This study aimed to identify potential predictors of non-attendance among children and adolescents with dental behaviour management problems (DBMP). A group of 179 patients, 7.5-19 yr of age, was grouped into 56 'non-attenders' (discontinued treatment, missed appointments, or >or= 20% cancellations) and 123 'attenders'. In addition to data from an introductory interview and dental recordings, baseline data from psychometric measures of fear and other personal and parental characteristics were included in logistic regression analyses and tree-based modelling. The non-attenders had higher scores on impulsivity and sociability and lower socio-economic status (SES) than the attenders, and they lived more often in single-parent families. Logistic regression analyses and tree-based modelling point to SES and parental anxiety as important predictors for non-attendance within this group of children and adolescents. To predict, and possibly to prevent, non-attendance among children and adolescents referred for specialized dental care because of DBMP, we must consider their lives and family situations as well as their personal characteristics and oral health status. Further research should focus on whether the observed associations between non-attendance and factors such as personal characteristics, family and psychosocial factors, and previous dental experiences, also hold for those who remain in regular dental care.

Genes with relevance for early to late progression of colon carcinoma based on combined genomic and transcriptomic information from the same patients.

BACKGROUND: Genetic and epigenetic alterations in colorectal cancer are numerous. However, it is difficult to judge whether such changes are primary or secondary to the appearance and progression of tumors. Therefore, the aim of the present study was to identify altered DNA regions with significant covariation to transcription alterations along colon cancer progression. METHODS: Tumor and normal colon tissue were obtained at primary operations from 24 patients selected by chance. DNA, RNA and microRNAs were extracted from the same biopsy material in all individuals and analyzed by oligo-nucleotide array-based comparative genomic hybridization (CGH), mRNA- and microRNA oligo-arrays. Statistical analyses were performed to assess statistical interactions (correlations, co-variations) between DNA copy number changes and significant alterations in gene and microRNA expression using appropriate parametric and non-parametric statistics. RESULTS: Main DNA alterations were located on chromosome 7, 8, 13 and 20. Tumor DNA copy number gain increased with tumor progression, significantly related to increased gene expression. Copy number loss was not observed in Dukes A tumors. There was no significant relationship between expressed genes and tumor progression across Dukes A-D tumors; and no relationship between tumor stage and the number of microRNAs with significantly altered expression. Interaction analyses identified overall 41 genes, which discriminated early Dukes A plus B tumors from late Dukes C plus D tumor; 28 of these genes remained with correlations between genomic and transcriptomic alterations in Dukes C plus D tumors and 17 in Dukes D. One microRNA (microR-663) showed interactions with DNA alterations in all Dukes A-D tumors. CONCLUSIONS: Our modeling confirms that colon cancer progression is related to genomic instability and altered gene expression. However, early invasive tumor growth seemed rather related to transcriptomic alterations, where changes in microRNA may be an early phenomenon, and less to DNA copy number changes.

Dental behaviour management problems among children and adolescents--a matter of understanding? Studies on dental fear, personal characteristics and psychosocial concomitants.

The primary aim of this thesis was to study dental fear, personal characteristics and psychosocial concomitants in relation to dental behaviour management problems (DBMP) and dental attendance. The study sample consisted of children (8-12 yrs) and adolescents (13-19 yrs) referred to the Specialized Paediatric Dental Clinic because of DBMP. They were compared to a reference group of same aged dental patients in ordinary dental care. A methodological study explored the Dental Subscale of the Children's Fear Survey Schedule (CFSS-DS) in terms of agreement between self and parental ratings and age- and gender-differentiated cut-off scores as compared to the commonly used. Baseline data on children's and adolescents' dental fear, psychosocial situation and everyday life, and personal characteristics were analysed according to a variable-based approach using logistic regression analyses and tree-based modelling of group differences. From the frequency of missed or/and cancelled appointments or interruption of dental treatment the group of referred children was separated into two groups (non-attendees vs. attendees). The differences between the groups were analysed using logistic regression analyses and tree-based modelling. It was found that children and adolescents referred because of DBMP differ in several ways from children and adolescents in ordinary dental care. These differences concerns dental fear, emotional and behavioural problems and temperamental aspects, as well as psychosocial concomitants. The results indicated an overall more negative and complex picture for the children and adolescents referred because of DBMP. The occurrence of single-parent families, child-parent separations, and professional support actions were clearly more frequent among patients referred because of DBMP. Dental fear was the only variable with consistent discriminatory capacity for DBMP through all age and gender subgroups. Aspects of anxiety, temperament, and behavioural symptoms contributed to the prediction of DBMP, but differently for different subgroups and at different levels of dental fear. A non-attending behaviour within the DBMP group was predicted by family factors and a temperamental profile indicating an out-going and somewhat impulsive personal profile. The results indicate further need to establish and validate age and gender differentiated cut-off scores and that self-rating on the CFSS-DS should complement parental ratings, since DF was the single best predictor of DBMP at clearly lower scores than commonly used. Avoidance may be seen as the extreme of DBMP, varying from irregular dental attendance to dropping out entirely from dental treatment. Therefore deeper knowledge and understanding of DBMP, will help the dental staff to meet and treat children and adolescents according to their individual need and act for the prevention of DBMP and irregular dental attendance.

Receptor and enzyme expression for prostanoid metabolism in colorectal cancer related to tumor tissue PGE2.

Prostaglandins support progression of colorectal cancer by several mechanisms. This conclusion is based on epidemiological and drug intervention long-term studies or retrieved from animal and cell culture experiments. The aim of the present study was to map receptor and enzyme expression for prostanoid metabolism in the presence of high or low PGE2 content within colon cancer tissue at primary tumor operation and after short-term preoperative provision of non-steroidal anti-inflammatory drug (NSAID). Twenty-three unselected patients with colon cancer were randomly selected to receive indomethacin (NSAID) or sham treatment for 3 days before surgery. Normal colon and tumor tissue were collected at operation for RNA extraction. Tissue PGE2 levels were measured by radioimmunoassay. Gene expression was quantified by microarray and real-time PCR. COX-1 expression increased proportionally to COX-2 expression in colon cancer tissue from untreated patients. Indomethacin reduced PGE2 content in normal and tumor tissue with subsequently decreased IP, HPGD and PPARgamma receptor expression in both tumor and normal colon tissue, while subtype EP1-4 receptors were not significantly influenced by indomethacin treatment. MPGES-1 expression was not related to overall PGE2 content in tumor and colon tissue, but decreased significantly in normal tissue during indomethacin exposure. Reduction of tumor tissue PGE2 was related to significant alteration in expression of several hundred genes indicating decreased cell cycling and increased apoptosis during indomethacin treatment, probably related to upregulation of acute phase reactants in tumor tissue. Increased prostanoid activity in colon cancer tissue is related to cross-talk between tumor and stroma cells.

Child dental fear as measured with the Dental Subscale of the Children's Fear Survey Schedule: the impact of referral status and type of informant (child versus parent).

OBJECTIVES: The first aim of this methodological study was to investigate the agreement between self-ratings of Children's Fear Survey Schedule (CFSS-DS). The second aim was to explore using differentiated cut-off scores, and to compare these cut-off scores with those commonly used. METHODS: Three different data collections included study groups (n = 497) of children and adolescents who had been referred to specialized pediatric dentistry clinics, and reference groups (n = 499) of dental patients and children rating the analyses were limited to the Östergötland sample (n = 210 + 228). Patients and their accompanying parents (mainly mothers) were asked to fill in the CFSS-DS independently. Cut-off scores on the CFSS-DS scale were determined using receiver-operating characteristic analysis; patient-parent agreement was illustrated with Bland-Altman plots. RESULTS: The patient-parent agreement was modest, particularly among those who were referred because of dental behaviour management problems (DBMP). Cut-off scores differentiated by age and gender, suggested by exploration according to two different methods, were with few exceptions clearly below the standard cut-off score. CONCLUSION: [corrected] The validity of parental ratings of their children dental fear should be questioned, particularly in high-fear populations. Self-ratings should, as far as possible, be used to complement parental ratings. One consequence of using the standard cut-off score is the risk of overlooking some patients needs for special attention. Further research is needed to establish and validate age-and gender-differentiated cut-off scores on the CFSS-DS.

Potential dermal exposure to methyl methacrylate among dental technicians; variability and determinants in a field study.

Methyl methacrylate (MMA) is a commonly used chemical in dental work that can cause dermatitis. Nineteen dental technicians participated in a field study in which potential dermal exposure to MMA and exposure determinants, including glove use and MMA vapour in the breathing zone, were repeatedly monitored during three consecutive days. Using patches placed on various parts of their hands we observed that the fingers and palms of the dental technicians were exposed to MMA, and their forefingers were significantly more exposed than their ring fingers; this is based on pooled data for both left and right hands (p = 0.04). The exposure variability was greater between workers than within worker (i.e. day-to-day variability), but the between worker variability was to some extent explained by a model which included the tested determinants. Neither the amount of MMA vapours in the breathing zone nor glove use was consistently correlated with the dermal exposure. Thus, the effects of glove use and the distribution of exposure to MMA on the hands in working environments needs to be further investigated.

Psychosocial concomitants to dental fear and behaviour management problems.

BACKGROUND: Children with dental behavioural management problems (DBMP) form a heterogeneous group, where personal characteristics play significant roles. Attention to everyday life and family situation as additional background facets may help to better understand and treat these patients. AIM: This study describes everyday life and family situation in child/adolescent patients referred because of DBMP, as compared to patients in ordinary dental care. DESIGN: A study group of 230 referred patients (8-19 years old; 118 girls) was compared to a reference group of 248 same-aged patients (142 girls) without DBMP. Patients and parents were interviewed according to a semistructured protocol. RESULTS: Patients referred because of DBMP more often lived in low socioeconomic status families, had parents not living together, fewer leisure-time activities, and were assessed as doing worse in social interactions compared to the reference group. Half of the study group had personal professional support, and some had experienced interventions by the social authorities. Whether these findings apply also to children/adolescents with DBMP who are not referred to specialist care remains to study. CONCLUSIONS: Many children and adolescents referred because of DBMP have a burdensome life and family situation. This should be paid attention to in research and in clinical care.

Prostanoid receptor expression in colorectal cancer related to tumor stage, differentiation and progression.

INTRODUCTION: Alterations in eicosanoid metabolism is well established in a variety of malignant tumors, particularly colorectal carcinoma. Recent studies in our laboratory have emphasized a role for EP subtype receptors in progression of colorectal cancer and disease specific mortality. Therefore, the aim of the present study was to extend our knowledge to include additional receptor expression (DP1, DP2, FP, IP, TP) for prostanoids (PGD2, TXA2, PGF2alpha, PGI2) in relationship to tumor stage, differentiation and progression of colorectal cancer. MATERIAL AND METHODS: Total RNA from 62 tumors and adjacent normal colon tissue (n = 48) was extracted. Quantification of receptor expression was performed by realtime PCR and related to the expression of an appropriate housekeeping gene (GAPDH). Tumors were assessed according to Dukes A-D (stage I-IV). RESULTS: DP1, DP2, FP and IP receptor subtypes displayed significantly reduced overall expression in tumor tissue compared to normal colon tissue, while the TP receptor subtype showed significantly higher expression in tumor tissue. Overall expression of the prostanoid receptors in tumor tissue was not related to clinical indexes as tumor stage and tumor cell differentiation evaluated by multivariate analyses. Cultured colorectal cancer cell lines with low (HT-29) and high (HCA-7) intrinsic PGE2 production at confluent state did not express DP1 and IP receptor subtypes, but displayed low expression of DP2, FP and TP receptor subtypes. CONCLUSION: The results in the present study indicate imbalanced expression of prostanoid receptors in colorectal cancer compared to normal colon tissue without clear cut relationship to disease progression. Therefore, future studies should be performed on defined cells within the tumor tissue compartment determining whether any prostanoid receptor(s) is useful as a molecular target in treatment or prevention of colorectal cancer.

Ozone air levels adjacent to a dental ozone gas delivery system.

OBJECTIVE: Ozone (O3) has been suggested as an anti-microbial treatment in dentistry, with an ozone gas delivery system introduced for the treatment of fissure and root caries. The aim of this study was to investigate the sealing capacity of the novel delivery system and its re-suction capacity during accidental displacement of the cup at different stages of ozone delivery. MATERIAL AND METHODS: Ozone leakage was studied in vitro after application on a flat metal surface and on buccal and occlusal tooth surfaces. An ozone analyzer was used to measure ozone gas concentrations adjacent to the delivering cups when adapted to the target surfaces during and after 10-20 s application cycles. The measured levels were compared with the background concentrations in the room. Measurements were performed 1) after complete ozone application cycles, 2) within the cycle before the start of the suction period, and 3) after displacements of the cup during the cycles. RESULTS: Ozone air values varied between 8 and 166 microgram/meter-3 for the flat metal surface and between 0 and 108 microgram/meter-3 for the tooth surfaces. Ozone leakage levels were 7.6 microgram/m-3 for the flat and and 7.4 microgram/meter-3 and 5.6 microgram/meter-3 for the buccal and occlusal surfaces, respectively, and 5.2 microgram/meter-3 and 9.8 microgram/meter-3 for the premolar and molar surfaces, respectively. Cycles with displacement showed significantly higher leakage levels than continuous complete cycles (p=0.03). CONCLUSIONS: Ozone application cycles with displacements showed significantly higher leakage levels than continuous complete cycles. The largest ozone delivery cups showed the highest leakage values. A change in background levels was seen with similar change in adjacent ozone levels. The overall measured ozone leakage values were low after normally functioning delivery cycles and after repeated displacements. The delivery system can be considered safe.

EP1-4 subtype, COX and PPAR gamma receptor expression in colorectal cancer in prediction of disease-specific mortality.

The importance of prostaglandins in tumor growth and progression is well recognized, including antineoplastic activities by cyclooxygenase (COX) inhibitors. Variation in treatment response to COX inhibition has questioned differences in expression of cell surface and nuclear membrane receptors among tumors with different disease progression. The purpose of this study was to evaluate whether EP(1-4) subtype, PPAR gamma receptor and COX-1/COX-2 expression in colorectal cancer are related to tumor-specific mortality. Reverse transcription-polymerase chain reaction and immunohistochemistry were used to demonstrate expression and protein appearance in tumor tissue compared with normal colon tissue. EP(1) and EP(2) subtype receptor protein was highly present in tumor cells, EP(3) occurred occasionally and EP(4) was not visible. PPAR gamma, EP(2) and EP(4) mRNA were significantly higher in normal colon tissue compared with tumor tissue, without any distinct relationship to Dukes A-D tumor stage. Multivariate analyses indicated that increased tumor tissue EP(2) and COX-2 expression predicted poor survival (p<0.001). COX-1 expression was significantly higher than COX-2 expression in normal colon tissue. Average COX-2 mRNA was not increased in tumor tissue compared with normal colon. However, most tumor cells stained positive for COX-2 protein, which was low or undetectable in normal mucosa cells. COX-1 protein was preferentially visible in stroma. EP(1-4) subtype receptor mRNAs were generally positively correlated to both COX-1 and COX-2 in tumor tissue, but not in normal colon. Our results imply that both prostaglandin production (COX-2) and signaling via EP(1-4) subtype receptors, particularly EP(2), predict disease-specific mortality in colorectal cancer.

Can NO(2) be used to indicate ambient and personal levels of benzene and 1,3-butadiene in air?

The aim of this study was to investigate the relation between two toxic volatile organic compounds, 1,3-butadiene and benzene, and a commonly used indicator of vehicle exhaust fumes, NO(2). This was to see if NO(2) can be used to indicate personal exposure to carcinogenic substances or at least estimate ambient levels measured at a stationary point. During the winter of 2001, 40 randomly selected persons living in the City of Umea (in the north of Sweden) were recruited to the study. Personal measurements of 1,3-butadiene, benzene and NO(2) were performed for one week, and were repeated for 20 of the 40 participants. Additional information was gathered using a diary kept by each participant. During the same time period weekly stationary measurements were performed at one urban background station and one street station in the city centre. The results from the personal measurements showed a negligible association of NO(2) with 1,3-butadiene (r= 0.06) as well as with benzene (r= 0.10), while the correlation coefficient between 1,3-butadiene and benzene was high and significant (r= 0.67). In contrast to the personal measurements, the stationary measurements showed strong relations between 1,3-butadiene, benzene and NO(2) both within and in-between the street and urban background station. This study supports NO(2) as a potential indicator for 1,3-butadiene and benzene levels in streets or urban background air, while the weak relations found for the personal measurements do not support the use of NO(2) as an indicator for personal 1,3-butadiene and benzene exposure.

Validation of the Willems badge diffusive sampler for nitrogen dioxide determinations in occupational environments.

The Willems badge, a diffusive sampler for nitrogen dioxide, has previously been validated for ambient air measurements. This paper describes the laboratory and field validation of the Willems badge for personal sampling under working environment conditions. The mean sampling rate in the laboratory tests was 46 ml min(-1), with an RSD of 12%. No statistically significant effects on sampling rate of the sampling time, concentration of NO2 or relative humidity were found. A slightly decreased sampling rate was observed at low wind velocity. This was also confirmed during static sampling, which makes the sampler less appropriate for static sampling indoors. No back diffusion was observed. Storage of the samplers for two weeks before or after exposure did not affect the sampling rate. Our analysis is based on a modified colorimetric method, performed by FIA (flow injection analysis). This technique was compared to ion chromatography analysis. The use of ion chromatography lowered the detection limit from 11 to 2 microg m(-3) for an 8 h sample, and furthermore enabled the detection of other anions. In conclusion, the diffusive sampler was found to perform well for personal measurements in industrial environments.