The importance of work organization on workload and musculoskeletal health--Grocery store work as a model.

We have evaluated the consequences of work organization on musculoskeletal health. Using a postal questionnaire, answered by 1600 female grocery store workers, their main work tasks were identified and four work groups were defined (cashier, picking, and delicatessen work, and a mixed group, who performed a mix of these tasks). The crude odds ratios (ORs) for neck/shoulder complaints were 1.5 (95% CI 1.0-2.2), 1.1 (0.7-1.5) and 1.6 (1.1-2.3), respectively, compared to mixed work. Adjusting for individual and psychosocial factors had no effect on these ORs. For elbows/hands, no significant differences were found. Technical measurements of the workload showed large differences between the work groups. Picking work was the most strenuous, while cashier work showed low loads. Quantitative measures of variation revealed for mixed work high between minutes variation and the highest between/within minutes variation. Combining work tasks with different physical exposure levels increases the variation and may reduce the risk of musculoskeletal complaints.

Uncertainty of blank correction in isotope ratio measurement.

Blank correction for isotope ratio measurement on small amounts of substances is often limited by presence of a blank, with an apparent isotopic composition different from that of the sample. For isotope ratios, blank correction is commonly performed either by the regression method, which works without the need for estimation of the blank, or by the subtraction method. With the subtraction method, estimation of the amount and isotope delta of the blank is required, and these estimates could be obtained either by direct, semi-indirect, or indirect measurement. Previously given expressions for the standard uncertainties of indirectly measured blank amounts and blank isotope deltas did not account for covariance between input quantities. In the present work, a previously published data set was re-evaluated, with covariance terms properly included in the calculation of uncertainties. It was shown that covariance effects may yield a significant reduction in uncertainty estimates, both for blank quantities and for blank corrected results. For series measurements on a standard material, it was also shown that the distribution of individual corrected isotope delta values around the average value was approximately normal, with its standard deviation equal to the estimated standard uncertainty of the corrected values. In most cases, it was observed that the regression and subtraction methods yield approximately the same blank corrected average values and uncertainties, regardless of method selected for estimation of blank quantities.

Reduction of bias in static closed chamber measurement of delta13C in soil CO2 efflux.

The (13)C/(12)C ratio of soil CO(2) efflux (delta(e)) is an important parameter in studies of ecosystem C dynamics, where the accuracy of estimated C flux rates depends on the measurement uncertainty of delta(e). The static closed chamber method is frequently used in the determination of delta(e), where the soil CO(2) efflux is accumulated in the headspace of a chamber placed on top of the soil surface. However, it has recently been shown that the estimate of delta(e) obtained by using this method could be significantly biased, which potentially diminish the usefulness of delta(e) for field applications. Here, analytical and numerical models were used to express the bias in delta(e) as mathematical functions of three system parameters: chamber height (H), chamber radius (R(c)), and soil air-filled porosity (theta). These expressions allow optimization of chamber size to yield a bias, which is at a level suitable for each particular application of the method. The numerical model was further used to quantify the effects on the delta(e) bias from (i) various designs for sealing of the chamber to ground, and (ii) inclusion of the commonly used purging step for reduction of the initial headspace CO(2) concentration. The present modeling work provided insights into the effects on the delta(e) bias from retardation and partial chamber bypass of the soil CO(2) efflux. The results presented here supported the continued use of the static closed chamber method for the determination of delta(e), with improved control of the bias component of its measurement uncertainty.

Precision of measurements of physical workload during standardized manual handling part III: goniometry of the wrists.

Goniometry of the wrist is a feasible method for studying wrist movements in most hand-intensive work. The precision and accuracy of the method per se is good. For the knowledge on validity of field measurements, the size of imprecision is of importance. This study evaluated this condition during standardized circumstances. Six women performed three different hand-intensive work tasks: 'materials picking', 'light assembly', and 'heavy assembly', repeated during three different days. Variance components between-days (within subjects) and between-subjects were derived for positions (flexion/extension and deviation) and movements, including angular velocities, % of time with very low velocity (<1 degree /s), as well as repetitiveness. For positions, the average standard deviations in the three tasks were, both between-days and between-subjects, 3-4 degrees . For movements, the coefficients of variation of angular velocities were about 10% between-days, and could to a great part be explained by differences in work rate. Between-subjects variability was higher, 20-40%. The variability was larger at low velocities than at high ones. The precision of the measured positions was good, expressed as small between-days and between-subjects variability. For movements, the between-days variability was also small, while there was a larger between-subjects variability. The imprecision of goniometry is consequently lower and comparable with inclinometry but lower than for EMG.

Precision of measurements of physical workload during standardised manual handling. Part II: Inclinometry of head, upper back, neck and upper arms.

For measuring the physical exposure/workload in studies of work-related musculoskeletal disorders, direct measurements are valuable. However, the between-days and between-subjects variability, as well as the precision of the method per se, are not well known. In a laboratory, six women performed three standardised assembly tasks, all of them repeated on three different days. Triaxial inclinometers were applied to the head, upper back and upper arms. Between-days (within subjects) and between-subjects (within tasks) variance components were derived for the 10th, 50th and 90th percentiles of the angular and the angular velocity distributions, and for the proportion of time spent in predefined angular sectors. For percentiles of the angular distributions, the average between-days variability was 3.4 degrees , and the between-subjects variability 4.0 degrees . For proportion of time spent in angular sectors, the variability depended on the percentage of time spent in the sector; the relative variability was scattered and large, on average 103% between days and 56% between subjects. For the angular velocity percentiles, the average between-days variability was 7.9%, and the average between-subjects variability was 22%. The contribution of the measurement procedure per se to the between-days variability, i.e., the imprecision of the method, was small: less than 2 degrees for angles and 3% for angular velocity.

Validity of self-assessed reports of occurrence and duration of occupational tasks.

To obtain quantitative estimates of the physical workload in epidemiological and intervention studies of musculoskeletal disorders, there is a need to extend task based exposure data to job exposure profiles. For this purpose a work task diary was developed and evaluated. This was validated against direct observations of a day's work for twenty-two female office workers and twenty female hospital cleaners. There was a good agreement regarding the occurrence of the main tasks. However, the less time-consuming tasks were under-reported. Moreover, about two thirds of the changes between tasks were not reported. The difficulties of defining tasks that function as occupational entities seems to be a major reason for the lack of agreement. The underestimation of the duration of breaks/pauses was most pronounced for the cleaners. Still, the diary would be useful for the calculation of job exposure, by time-weighting task exposure data, when the tasks and/or their duration vary between days.

Precision of measurements of physical workload during standardised manual handling. Part I: surface electromyography of m. trapezius, m. infraspinatus and the forearm extensors.

Though surface electromyography (EMG) has been widely used in studies of occupational exposure, its precision in terms of the variance between-days and between-subjects has seldom been evaluated. This study aimed at such an evaluation. Six women performed three different work tasks: 'materials picking', 'light assembly', and 'heavy assembly', repeated on 3 different days. EMG was recorded from m. trapezius, m. infraspinatus and the forearm extensors. Normalisation was made to a maximal (MVE), and a submaximal (RVE), reference contraction. Variance components between days (within subjects) and between subjects were derived for the 10th, 50th and 90th percentiles, as well as for muscular rest parameters. For the task 'heavy assembly', the coefficient of variation between days (CV(BD)) was 8% for m. trapezius (right side, 50th percentile, MVE normalised values). Larger variabilities were found for m. infraspinatus (CV(BD) 15%), and the forearm extensors (CV(BD) 33%). Between-subjects variability (CV(BS)) was greater, 16% for m. trapezius and 57% for m. infraspinatus, 29% for the forearm extensors. RVE normalisation resulted in larger CV(BD), while reducing CV(BS). The between-days and between-subjects variability may be used to optimise sampling strategy, and to assess the bias in epidemiological studies. The bias caused by measurement procedures per se is acceptable.

Measurements of wrist and forearm positions and movements: effect of, and compensation for, goniometer crosstalk.

Flexible biaxial goniometers are extensively used for measuring wrist positions and movements. However, they display an inherent crosstalk error. The aim was to evaluate the effect, of this error, on summary measures used for characterizing manual work. A goniometer and a torsiometer were combined into one device. An algorithm that effectively compensated for crosstalk was developed. Recordings from 25 women, performing five worktasks, were analyzed, both with and without compensation for crosstalk. The errors in the 10th, 50th and 90th percentiles of the flexion/extension distributions were small, on average <1 degrees. The ulnar/radial deviation distributions were weakly dependent on forearm position. The flexion/extension velocity measures were, for the 50th and 90th percentiles, as well as the mean velocity, consistently underestimated by, on average, 3.9%. For ulnar/radial deviation, the velocity errors were less consistent. Mean power frequency, which is a measure of repetitiveness, was insensitive (error <1%) to crosstalk. The forearm supination/pronation angular distributions were wider, and the velocities higher, than for the wrists. Considering wrist/hand exposure in epidemiologic studies, as well as for establishing and surveillance of exposure limits for prevention of work-related upper extremity musculoskeletal disorders, the crosstalk error can, when considering other errors and sources to variation, be disregarded.

Self-assessed and directly measured occupational physical activities--influence of musculoskeletal complaints, age and gender.

This study compares questionnaire assessed physical activity with direct technical measurements among cleaners and office workers, stratified regarding age, gender and self-reported neck/shoulder complaints. During two full working days number of steps was recorded by a pedometer, sitting/standing positions by a posimeter and heart rate by a Sport-Tester. In addition the subjects kept a work task diary for 10 days. There were high intra-individual variations in exposure between the days. Subjects with complaints rated their exposure higher than those without, although they in fact showed lower direct measured exposure. This may imply underestimation of exposure-effect relationships. Rate of perceived exertion showed low correlation with heart rate ratio within the two occupational groups, but high, 0.64 when the two groups were combined. Age and complaints explained 31% of the variance for the cleaners.

Plasma neutrophil lipocalin, elastase-alpha1-antitrypsin complex and neutrophil protease 4 in preterm infants with respiratory distress syndrome.

Respiratory distress syndrome (RDS) and chronic lung disease of prematurity (CLD) are associated with inflammation of the airways and interstitial tissue of the lung. It is hypothesized that RDS severity and the risk of developing CLD may be correlated with neutrophil gelatinase-associated lipocalin (NGAL), a marker of leucocyte activity, human elastase-alpha1-antitrypsin complex (HEAT) or free and complexed neutrophil protease 4 (NP4), markers of proteolytic enzyme secretion from granulocytes. Thirty-three preterm infants with RDS were enrolled in the study and plasma sampled between 3 and 14 days of life. NGAL, HEAT and NP4 concentrations varied widely in infants with RDS. Significant correlations between subsequent development of CLD and plasma concentrations of HEAT and NP4, respectively, were found on days 3-4 of life, p=0.006 and p=0.02, respectively.

Nitrogen isotope analysis of ammonium in aqueous solutions using a perfluorosulfonated ionomer membrane for solid-phase microextraction.

The use of custom-made solid-phase microextraction (SPME) fibers coated with a perfluorosulfonated ionomer, Nafion, was investigated for nitrogen isotopic analysis of ammonium in aqueous solutions. Aqueous ammonium was converted to ammonia by addition of a base, followed by absorption from the headspace, desorption in the injection port of a gas chromatograph, and analysis by gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). Fibers coated with a Nafion tubing were chosen due to a higher fiber-gas distribution constant and a higher Nafion thickness than fibers coated with Nafion solution, both leading to a higher amount of ammonia absorbed at equilibrium. The Nafion membrane-coated fiber absorbed approximately 20 times more than a commercial polydimethylsiloxane (PDMS) fiber. The isotopic fractionation between fiber and gas was 1.0117 +/- 0.0009 (standard deviation, SD, of all measurements) at an initial ammonia gas concentration of 21-210 microM. At 390 microM initial gas concentration it was slightly lower. When sampling from liquid samples, an ammonium concentration of 10 mM was needed to obtain a sufficient amount of ammonia absorbed. Modeling of the absorption at different temperatures showed that the absorption was approximately constant in the temperature range suitable for SPME experiments. Absorption at room temperature was therefore used for simplicity. A pilot study was conducted in which absorption was achieved from a single 9 microL droplet of sample. The preliminary results showed that delta(15)N analysis was possible for only 0.4-0.5 micromol of ammonium with a SD of 0.8 per thousand (n = 5).

Increased expression of the secretory leukocyte proteinase inhibitor in Wegener's granulomatosis.

The secretory leucocyte proteinase inhibitor (SLPI) is a low molecular weight, tissue-specific inhibitor of proteases, such as elastase and cathepsin G. It is the major local protease inhibitor in the upper airways. Proteinase 3, the main autoantigen in Wegener's granulomatosis (WG), can degrade SLPI proteolytically. In addition, SLPI is sensitive to oxidative inactivation by myeloperoxidase-generated free oxygen radicals. SLPI also has an antimicrobial capacity that can be of interest, as infection is considered to play a role in the pathogenesis of WG. This study focuses on SLPI expression in patients suffering from WG, something that to our knowledge has not been explored hitherto. Serum samples and nasal biopsies were obtained from 12 Swedish WG patients, while buffy coats were obtained from 33 American WG patients. SLPI levels in serum were measured by means of ELISA and the protein was detected by means of immunohistochemistry in nasal biopsies. mRNA expression was studied by means of in situ hybridization on nasal biopsies and RT-PCR on leucocytes. IL-6 or ESR were measured as markers of inflammatory activity. Cystatin C or creatinine was measured as a marker of renal filtration. White blood cell counts were registered. In serum, we found close to normal SLPI levels, without any correlation to IL-6. Two patients had greatly elevated values, both of them suffering from severe renal engagement. Strong SLPI mRNA expression was found in nasal biopsies. RT-PCR on leucocyte mRNA showed normal or greatly elevated expression of SLPI mRNA, correlating with disease activity. Leukocyte SLPI expression seems to be up-regulated in active WG. Serum levels were measured in a small number of patients and were found to be close to normal. Lack of correlation to the acute phase response indicates a specific regulation. This might be linked to an altered protease/antiprotease balance. These findings could indicate that SLPI locally participates in the anti-inflammatory and perhaps antimicrobial response in WG.

Tracheobronchial aspirate fluid neutrophil lipocalin, elastase- and neutrophil protease-4-alpha1-antitrypsin complexes, protease inhibitors and free proteolytic activity in respiratory distress syndrome.

UNLABELLED: This study aimed to determine whether the protease/protease inhibitor balance and neutrophil activity is of pathophysiological importance in the severity and resolution of respiratory distress syndrome (RDS) and the eventual development of neonatal chronic lung disease (CLD). Ventilated preterm infants with RDS (n = 43) were studied during their first week of life. Tracheobronchial aspirate fluid (TAF) concentrations of neutrophil lipocalin, the elastase- and neutrophil protease-4 (NP4) complex concentrations, and alpha1-antitrypsin (alpha1AT), antichymotrypsin (ACT) and secretory leucocyte protease inhibitor (SLPI) levels were analysed. Free proteolytic and elastolytic activities were also determined. CLD correlated with low alpha1AT (p = 0.02) and ACT (p = 0.02) levels at 3-4 d of age and low SLPI (p = 0.03) at 7-8 d of age. No correlations were found between CLD or severity of RDS (as judged from radiological examination) and neutrophil lipocalin, elastase- and NP4-alpha1AT complexes during the first week of life, with one exception: RDS X-ray severity and the elastase-alpha1AT complex concentration were correlated at 3-4d of age (p = 0.02). Free proteolytic activity occurred in the TAF of 7/30 infants tested on day 3-4 and free elastolytic activity in 1 patient. During the rest of the first week of life no free elastolytic or proteolytic activities were observed. Caesarean section was correlated with low levels of SLPI on day 3-4 (p = 0.01), NP4 (p = 0.03) and ACT (p = 0.05) on day 5-6. Gestational age was positively correlated with protease inhibitors and their complexes at 3-4 d of age. CONCLUSION: Free proteolytic or elastolytic activity in the TAF of RDS infants in the first week of life occurred by way of exception. Elastase-/NP4-alpha1AT complex or neutrophil lipocalin levels were not correlated with the development of CLD. The correlation between CLD and low alpha1AT or ACT at 3-4 d and SLPI at 7-8 d of age may be due to either immaturity or complex formation. The severity of RDS as judged from radiological examination was correlated with elastase-alpha1AT complex on day 3-4. The main hypothesis, that TAF protease/protease inhibitor levels or imbalance and leucocyte activity are important factors indicating a high risk of severe RDS and subsequent CLD development, was principally not confirmed.

Determination of the 15N/14N ratio of ammonium and ammonia in aqueous solutions by equilibrium headspace-gas chromatography-combustion-isotope ratio mass spectrometry.

A method for determination of the 15N/14N ratio of total ammoniacal nitrogen (TAN; ammonium and ammonia) in aqueous solutions was developed, primarily intended for use with soil extracts, which have a high TAN level, e.g. from recently fertilised agricultural soils. Ammonium was converted to ammonia by addition of NaOH, followed by nitrogen isotopic analysis of the headspace by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) where complete separation of TAN from the matrix was not necessary. The ammonia concentration in the gas phase was maximised by increasing the temperature and salt concentration and by decreasing the gas liquid ratio in the headspace vials. Isotopic equilibrium was reached after less than 1 h at 80 degrees C. The measured isotopic ratio was constant for solutions containing 30-200 mM NH4-N, corresponding to 950-7000 ng NH3-N detected with the IRMS. The integrated area response at m/z 28 increased linearly with the ammonium ion concentration in the interval 10-200 mM NH4-N. The fractionation factor between the liquid and gas phases was 1.0054 +/- 0.0007 within the linear range, which is in agreement with values reported in the literature, but with a higher precision. Changes in temperature, gas:liquid ratio or salt concentration did not affect the measured ratio, demonstrating the robustness of the developed method.

Factors associated with the development of arm lymphedema following breast cancer treatment: a match pair case-control study.

We examined factors that may influence the development of arm lymphedema following breast cancer treatment including the specific mode of therapy, patient occupation and life style. Medical record data and a questionnaire were used to collect information after surgery concerning such issues as wound seroma, infection, adjuvant treatment, vessel string (phlebitis), body mass index, smoking habits and stress. Occupational workload was assessed after surgery whereas housework, exercise, hobbies and body weight were assessed both before and after surgery. Seventy-one breast cancer treated women with arm lymphedema lasting more than 6 months but less than 2 years were matched to women similarly treated for breast cancer but without arm lymphedema (controls). The matching factors included axillary node status, time after axillary dissection, and age. In the lymphedema group, there was a higher body mass index at time of surgery (p=0.03) as well at time of study (p=0.04). No differences were found in occupational workload (n=38) or housework, but the lymphedema group reduced their spare time activities including exercise after surgery compared with the controls (p<0.01). In conclusion, women treated for breast cancer with axillary node dissection with or without adjuvant radiotherapy could maintain their level of physical activity and occupational workload after treatment without an added risk of developing arm lymphedema. On the other hand, a higher BMI before and after operation increases the lymphedema risk.

The presence of elafin, SLPI, IL1-RA and STNFalpha RI in head and neck squamous cell carcinomas and their relation to the degree of tumour differentiation.

Biopsy samples of head and neck carcinomas were investigated with regard to elafin, secretory leukocyte protease inhibitor (SLPI), interleukin 1-receptor antagonist [(IL)1-RA] and soluble tumour necrosis factor alpha receptor antagonist (STNFalpha RI). SLPI and elafin are serine protease inhibitors produced in the serous cells of the upper respiratory airways and in the keratinocytes, respectively. We have now found the presence of elafin and SLPI in squamous cell carcinomas of the upper respiratory tract (tonsillar, hypopharyngeal, tongue, mouth floor, gingival and laryngeal cancer). Significantly higher amounts of SLPI and elafin are present in well-differentiated and moderately differentiated tumours than in poorly differentiated tumours (p < 0.0001 and p < 0.0015). Tumour necrosis factor-alpha and IL-1beta have been shown to stimulate the production of SLPI and elafin. Since these cytokines can both be difficult to detect, we chose to study their inhibitors, STNFalpha RI and IL1-RA, instead. IL1-RA was expressed in highly differentiated tumours as well as in poorly differentiated ones. No significant difference was seen between the groups. STNFalpha RI was only found in very small amounts, sparsely distributed in the tumours, and was not related to the degree of differentiation.

Interleukin-1 receptor antagonist is detectable in human carotid artery plaques and is related to triglyceride levels and Chlamydia pneumoniae IgA antibodies.

OBJECTIVES: To investigate whether the interleukin-1 receptor antagonist (Il-1ra) and interleukin-1beta (Il-1beta) can be detected in human carotid artery tissue, and whether their presence is related to evidence of Chlamydia pneumoniae infection, risk factors for atherosclerosis, and clinical data. SETTING: Departments of Vascular Diseases and Surgical Pathophysiology, University Hospital, Malmö, Sweden. SUBJECTS: A total of 66 patients undergoing carotid endarterectomy (median age 74, range 53-89 years, 26 women). Il-1beta and Il-1ra were studied in carotid artery plaques and in Il-1ra in serum. RESULTS: Interleukin-1 receptor antagonist was detected in mononuclear cells in plaques from 37/66 (56%) patients. Patients with Il-1ra in plaques showed higher [2.04 (1.70-3.14) mmol x L(-1) vs. 1.69 (1.09-1.99) mmol x L(-1); P < 0.05] serum(s-)triglyceride(tg) levels, and a higher frequency of IgA seropositivity for C. pneumoniae (76% vs. 52%; P < 0.05) than those without. S-Il-1ra levels correlated with s-tg levels (r=0.38; P=0.047). There were no differences between patients with and without Il-1ra in plaques concerning s-Il-1ra, blood(b-)haemoglobin or leucocyte count, s-cholesterol, b-glucose, blood pressure, IgG seropositivity for C. pneumoniae, prevalence of neurological symptoms preceding operation, smoking, or diabetes mellitus. There were no differences in frequency of Il-1ra in plaques or in s-Il-1ra levels between patients with symptomatic and asymptomatic stenosis, between smokers and nonsmokers, or between diabetic and nondiabetic patients. Il-1beta was not detected in plaques in the current study. CONCLUSION: Interleukin-1 receptor antagonist can be detected in human atherosclerotic carotid artery plaques, and is related to s-triglyceride levels and IgA seropositivity for C. pneumoniae, but not to prevalence of neurological symptoms related to embolization.

Neutrophil elastase and secretory leukocyte protease inhibitor in prelabor rupture of membranes, parturition and intra-amniotic infection.

OBJECTIVE: Neutrophil elastase (NE), a multifunctional serine protease stored in azurophilic granules of mature neutrophils, is capable of intracellular degradation of proteins during phagocytosis and extracellular degradation of connective tissue during an inflammatory process. Secretory leukocyte protease inhibitor (SLPI) is a natural NE inhibitor present in amniotic fluid, fetal membranes and cervical mucus. An imbalance between NE and SLPI has been implicated as a mechanism of abnormal tissue destruction in chronic inflammatory diseases. The purpose of this study was to determine if parturition, premature rupture of the membranes (PROM) and microbial invasion of the amniotic cavity are associated with changes in amniotic fluid concentrations of NE and SLPI. STUDY DESIGN: Amniotic fluid was retrieved by amniocentesis from 380 patients in the following groups: (1) preterm labor and intact membranes without microbial invasion of the amniotic cavity who delivered at term (n = 13) or prematurely (n = 26), and preterm labor with microbial invasion of the amniotic cavity (n = 9); (2) preterm PROM with (n = 34) and without (n = 51) microbial invasion of the amniotic cavity; and (3) term gestation without microbial invasion of the amniotic cavity with intact membranes not in labor (n = 63), in labor (n = 158), and with rupture of membranes not in labor (n = 26). Microbial invasion of the amniotic cavity was determined by a positive amniotic fluid culture for micro-organisms including aerobic, anaerobic and Mycoplasma species. NE and SLPI amniotic fluid levels were determined by highly specific and sensitive immunoassays. RESULTS: Preterm PROM was associated with a significant increase in the amniotic fluid concentration of NE. Microbial invasion of the amniotic cavity was associated with a significant increase in the amniotic fluid concentration of NE in women with preterm labor and intact membranes, as well as in women with preterm PROM. Term and preterm parturition was associated with a significant increase in the amniotic fluid concentration of NE. In the absence of microbial invasion of the amniotic cavity, preterm and term PROM were associated with a significant reduction in the amniotic fluid concentration of SLPI. CONCLUSION: Preterm PROM, microbial invasion of the amniotic cavity, and parturition at term and preterm are associated with a significant increase in the amniotic fluid concentration of NE. PROM is associated with a reduced amniotic fluid concentration of SLPI.

Turnover of 125I-labelled tissue kallikrein following intraduodenal or intravenous administration.

UNLABELLED: Tissue kallikrein is released in the body both physiologically and in many inflammatory disorders. Little is, however, known about the turnover of released tissue kallikrein in humans. Approximately 1 mg of tissue kallikrein (mol wt 43,000 Da) was purified from 85 L human urine by: (1) ultracentrifugation, (2) filtration through an aprotinin-coupled Sepharose 4B column, followed by (3) gel filtration over a Sephadex G-75 column. The elimination, after intraduodenal or intravenous administration of purified tissue kallikrein radiolabelled with 125I, was followed by collecting serial samples of plasma, urine and faeces from three volunteers. Within 72 h, about 96% of the intraduodenally administered radioactivity had been excreted in urine, and approximately 5.4% in faeces, mainly as 125I. No intact 125I-tissue kallikrein was found in plasma, urine or faeces after the intraduodenal instillation of the protein. The plasma half-life of 125I-tissue kallikrein up to 3 h after intravenous injection was 9 min and, thereafter, 20 h. The 125I-tissue kallikrein was quickly bound to a plasma protein with a mol wt of about 67 kDa, but some of the radioiodinated tissue kallikrein was still unbound 15 min after injection, judged by gel filtration on Sephadex G-200 columns. Most of the radioactivity was excreted in the urine as 125I, but about 4-6% was recovered as free 125I-tissue kallikrein. CONCLUSION: The use of tissue kallikrein as an oral drug appears, therefore, to be useless. Tissue kallikrein released into plasma seems to be quickly bound to a protein with a mol wt of 67 kDa, probably kallistatin or Protein C inhibitor, but some tissue kallikrein seems to be unbound and may have some physiological or pathophysiological action. The unbound tissue kallikrein is, at least partly, cleared from the circulation by the kidneys, and tissue kallikrein in the urine may partly be derived from plasma.

Questionnaire versus direct technical measurements in assessing postures and movements of the head, upper back, arms and hands.

OBJECTIVES: This study compares questionnaire-assessed exposure data on work postures and movements with direct technical measurements. METHODS: Inclinometers and goniometers were used to make full workday measurements of 41 office workers and 41 cleaners, stratified for such factors as musculoskeletal complaints. The subjects answered a questionnaire on work postures of the head, back, and upper arms and repeated movements of the arms and hands (3-point scales). The questionnaire had been developed on the basis of a previously validated one. For assessing worktasks and their durations, the subjects kept a 2-week worktask diary. Job exposure was individually calculated by time-weighting the task exposure measurements according to the diary. RESULTS: The agreement between the self-assessed and measured postures and movements was low (kappa = 0.06 for the mean within the occupational groups and kappa = 0.27 for the whole group). Cleaners had a higher measured workload than office workers giving the same questionnaire response. Moreover, the subjects with neck-shoulder complaints rated their exposure to movements as higher than those without complaints but with the same measured mechanical exposure. In addition, these subjects also showed a general tendency to rate their postural exposure as higher. The women rated their exposure higher than the men did. CONCLUSIONS: The questionnaire-assessed exposure data had low validity. For the various response categories the measured exposure depended on occupation. Furthermore, there was a differential misclassification due to musculoskeletal complaints and gender. Thus it seems difficult to construct valid questionnaires on mechanical exposure for establishing generic exposure-response relations in epidemiologic studies, especially cross-sectional ones. Direct technical measurements may be preferable.