Measuring dust on skin with a small vacuuming sampler--a comparison with other sampling techniques

Airborne skin exposure to allergens and irritants may cause dermatitis. There are few methods for assessing skin exposure to airborne particles. We have modified and tested a vacuuming sampler for removing particles from the skin. The sampler was compared with two other skin and surface exposure sampling techniques. These were based on surrogate skin (a patch sampler-adhesive tape on an optical cover glass) and a tape stripping removal procedure. All three samplers measure the mass of dust on skin. Dust containing starch was deposited onto the skin in a whole-body exposure chamber. Samples were taken from forearms and shoulders and analysed using optical microscopy. With the different sampling techniques small differences in the results were obtained. Agreement between the vacuuming sampler and the tape stripping technique was good. The comparison between patch and tape stripping procedure indicated a slight overestimation for the patch. The three techniques are applicable for assessing skin exposure to particles and for dose-effect studies. The vacuuming method will be further developed and applied in workplace studies. The technique allows for dust sampling from large areas of skin.     

Thyroid cancer after X-ray treatment of benign disorders of the cervical spine in adults

While there is very good epidemiological evidence for induction of thyroid cancer by radiation exposure in children, the risk for adults after exposure is still uncertain, especially when concerning relatively small radiation doses. A cohort of 27,415 persons which in 1950 through 1964 had received x-ray treatment for various benign disorders in the locomotor system (such as painful arthrosis and spondylosis) was selected from three hospitals in Northern Sweden. A proportion of this cohort, consisting of 8 ,44 persons (4,075 men and 4,069 women), had received treatment to the cervical spine and thereby received an estimated average dose in the thyroid gland of about 1 Gy. Standard incidence rates (SIR) were calculated by using the Swedish Cancer Register. In the cervical spine cohort, 22 thyroid cancers were found versus 13.77 expected (SIR 1.60, CI 1.00-2.42). The corresponding figures for women were 16 observed cases versus 9.60 expected cases (SIR 1.67: Cl 0.75-2.71). Most thyroid cancers (15 out of 22) were diagnosed > 15 years after the exposure. In the remaining part of the total cohort, i.e. those without cervical spine exposure, no increased risk of thyroid cancer was found (SIR 0.98, CI 0.64-1.38). The study strongly suggests that external radiation exposure of adults at relatively small doses increases the risk of thyroid cancer but also that this increase is very much lower than that reported after exposure in children.     

Evaluation of exhaled nitric oxide in schoolchildren at different exhalation flow rates

Nitric oxide (NO) in exhaled air is believed to reflect allergic inflammation in the airways. Measured levels of exhaled NO vary with the exhaled flow rate, which therefore must be standardized. The aim of this study was to estimate the optimal exhalation flow rate when measuring NO in exhaled air. We studied 15 asthmatic children (8-18 y) with elevated NO levels and 15 age-matched controls and focused on how the quality of the NO curve profile, the discriminatory power, and the reproducibility were influenced by the exhalation flow rate. We used an on-line system for NO measurements at six different exhalation flow rates in the interval of 11-382 mL/s. The fraction of exhaled nitric oxide (FENO) was highly flow-dependent as was expected. Intermediate flow rates yielded a flat and stable NO plateau and were considerably easier to interpret than those obtained at the highest and lowest flow rates. The ratio of FENO between asthmatics and controls was lower at higher flow rates and a considerable overlap in NO values was demonstrated at all flow rates except 50 mL/s. The reproducibility was much lower at more extreme flow rates and was best at 50 mL/s. We conclude that a target exhalation flow rate of approximately 50 mL/s is to be preferred using the single-breath method for on-line NO measurements in schoolchildren.     

Effects of a lipid lowering fibrate and hormone replacement therapy on serum lipids and lipoproteins in overweight postmenopausal women with elevated triglycerides

BACKGROUND: Cardiovascular disease (CVD) is the leading cause of death in women after menopause. In essence major risk factors for CVD are similar in women as for men inclusive of serum lipid perturbations. The effects of estrogens and hormone replacement therapy on lipid metabolism is widely discussed and warrant further evaluation especially when combined with other lipid lowering drugs. STUDY DESIGN: Postmenopausal women were studied by an open randomised study during 9 months. Subjects were recruited from outpatient clinics in a rural area of Sweden. Major inclusive criteria comprised body mass index (BMI) >28, serum triglycerides >1.5 mmol/l. Participants were at least 12 months postmenopause with a concomitant serum Follicle Stimulating Hormone (FSH) above 28 IU/l. After inclusion in the study patients were instructed to adhere to a low-fat and caloric diet for 3 months and after this period randomised into two groups of intervention; a lipidlowering fibrate (LLF) group and one hormone replacement therapy group (HRT). The LLF group was given gemfibrozil 600 mg orally twice daily and HRT group received 2 mg oestradiol in combination with 1 mg norethisterone acetate as a continuous combined therapy once daily. After 3 months, the LLF group added the HRT regimen and patients in the HRT group added gemfibrozil. Hence, all participants received the regimens combined for the last 6 months of the study. RESULTS: Serum s-cholesterol was markedly decreased in both groups during the first 3 months of single treatment (P<0.0001). This decrease reflected a reduction especially of calculated low density lipoprotein (LDL) s-cholesterol (P<0.001). High density lipoprotein (HDL) s-cholesterol was reduced in the HRT group (P<0.005) but increased (P<0.004) in the LLF group. Triglycerides were also decreased by both treatments but more marked in the LLF group (P<0.0001) than in the HRT group (P<0.02). After 9 months the reduction remained in both groups but no additive effects were encountered in any of the groups. CONCLUSION: The effects by gemfibrozil on s-cholesterol and triglycerides levels seem to be superior to continuous combined HRT in overweight women with elevated triglycerides. The combination of the two drugs did not seem to offer any additional benefit concerning the routine serum lipid or lipoprotein profile.     

Simple method based on fluorescent detection for the determination of 4-hydroxycyclophosphamide in plasma

Cyclophosphamide is a prodrug used both as a single drug and in combination chemotherapy. Cyclophosphamide is converted to its active metabolite (4-hydroxycyclophosphamide) by the cytochrome P450 enzymes. A liquid chromatography method including liquid-liquid extraction and protein precipitation in one step was developed to measure 4-hydroxycyclophosphamide in plasma. The 4-hydroxycyclophosphamide was stabilized and converted to a fluorescent dansylhydrazone derivative, which was chromatographed on a reverse-phase column and detected using a spectrofluorometric detector at excitation of 350 nm and emission of 550 nm. The limit of quantitation was 60 ng/mL and the between-day accuracy and precision were less than 9%. The method was applied to the analysis of plasma from patients who had received an intravenous infusion of 1 g/m(2) cyclophosphamide.     

Increased Level of Soluble HLA Class I Antigens in Systemic Lupus Erythematosus: Correlation with Anti-DNA Antibodies and Leukopenia

The concentration of soluble HLA class I (sHLA-I) was measured by ELISA in serum samples from 30 well-characterised SLE patients at high and low disease activity states and from 100 healthy controls. HLA-A allotypes in the patients were analysed by a PCR-based typing technique. A higher level of sHLA-I was found in SLE patient sera both at high and low disease activity than in controls (P< 0.001). The sHLA-I level was further increased during active disease (P< 0.01). Concentrations of sHLA-I correlated with anti-dsDNA antibodies at high disease activity, but not with disease activity as analysed by a modified SLEDAI. Numbers of leukocytes and lymphocytes, as well as levels of C1q and C3 correlated inversely with sHLA-I concentration. In five serial samples from ten patients the sHLA-I level co-varied with disease activity. Presence of HLA allotype A9 was associated with higher sHLA-I levels in both patients (P< 0.001) and controls (P< 0.001). We conclude that the increased sHLA-I concentration in SLE patients was related to several laboratory parameters reflecting disease activity suggesting that sHLA-I molecules are connected with the disease process. Increased sHLA-I level due to HLA-A allotype was not a disease susceptibility factor for SLE.     

Calculated moment-arm and muscle-tendon lengths during gait differ substantially using MR based versus rescaled generic lower-limb musculoskeletal models

Biomechanical analysis of gait relies on the use of lower-limb musculoskeletal models. Most models are based on a generic model which takes into account the subject's skeletal dimensions by isotropic or anisotropic rescaling. Alternatively, personalized models can be built based on information from magnetic resonance (MR) images. We have studied the effect of these approaches on muscle-tendon lengths (MTLs) and moment-arm lengths (MALs) for 16 major muscles of the lower limb of a normal adult during both normal and pathologic gait. For most muscles, the MTL and MAL calculated using the rescaled generic models showed high correlation values, but large offsets when compared to values calculated using personalized models. MTL and MAL differences with the personalized model are only slightly smaller for an anisotropic than for an isotropic rescaled model. Gait kinematics influenced the observed inter-model differences and correlations due to an altered range of joint angles in both gait patterns. In conclusion, both generic rescaling methods failed to accurately estimate absolute values for MTL and MAL calculated using the personalized model. However, the magnitude of MTL and MAL changes during normal and pathologic gait corresponded between all three models for most muscles. Since rescaling depends strongly on modelling assumptions and cannot fully take into account subject-specific musculoskeletal geometry, interpretation of MTL and MAL even in normal adult subjects requires extreme caution.     

The relationship between socio-economic status, parental support and adolescent physical activity

Aim: To examine: 1) the association between socio-economic status and adolescent physical activity; 2) to assess links between mothers' and fathers' social support and adolescents' physical activity. Methods: Participants were 326 urban adolescents and their parents. Physical activity was measured using a 7-d physical activity recall. Socio-economic status and parents' social support was assessed using questionnaires. Results: Boys were significantly more active than girls, and fathers' explicit modelling towards boys was higher compared to girls. In contrast, fathers' and mothers' logistic support was significantly higher towards their daughters. Social class and fathers' and mothers' social support were significantly related to adolescent self-reported physical activity. Fathers' explicit modelling was the strongest predictor of adolescent physical activity, predicting 13.5% of the total variance. Social class, fathers' logistic support and mothers' explicit modelling were also significant predictors, accounting for additional 14% of the variance in adolescents' weekly physical activity.
Conclusion: Parental support and social class are positively related to physical activity in Estonian adolescents.     

Fecal sterols and bacterial β‐glucuronidase activity: A preliminary metabolic epidemiology study of healthy volunteers from Umea,Sweden, and metropolitan New York

The dietary pattern, fecal bile acid and neutral sterol concentrations, and the bacterial β‐glucuronidase activity of 2 population groups with a varied risk for colon cancer development (i.e., a high‐risk population in the metropolitan New York area and an intermediate‐risk population in Umea, Sweden) were investigated. The average daily intake of dietary protein was the same in the 2 groups, but the fat intake was higher in Umea than in New York. The daily total fiber intake was also higher in Umea, as was the daily total stool output. The concentration of fecal secondary bile acids and β‐glucuronidase activity was lower in Umea than in New York, but the total daily excretion of these constituents was the same in both groups. The data suggest that one of the factors contributing to the lower risk of colon cancer in Umea, despite the high dietary fat intake, is the high intake of dietary whole grain and cereal fiber, which leads to an increase in stool bulk, thus diluting and/or binding promoters.     

Relationship Between Various Physical Activity Domains and Self-Perceived Health and Obesity in Women

The purpose of this study was to determine the relationship between self-perceived health and obesity and recreational, occupational, commuting, and total physical activity in women. The sample included 956 Estonian women aged 18–50. Cross-sectional data were collected in the Estonian Women Physical Activity Study via a mail-out survey in 2008 using the Global Physical Activity Questionnaire and self-reported measures of health indicators. The associations between physical activity and health indicators were examined using multiple logistic regression and were adjusted for potential confounding factors (age, education, and income). The women in the highest occupational physical activity group were significantly less likely to have good health (OR 0.51; CI 0.33–0.77) compared to women with no occupational physical activity. A significant association was observed, however, between being in the highest recreational physical activity group and having better self-perceived health (OR = 2.09, 95% CI 1.36–3.21) and not being obese (BMI ≥ 30) (OR = 0.42, 95% CI 0.21–0.86). A higher total amount of physical activity was not related to better health status or obesity. These findings suggest that the specific domains of physical activity may be more important for self-perceived health and obesity among women than the total amount of physical activity.