Correlations between Ratings and Technical Measurements in Hand-Intensive Work

An accurate rating of hand activity and force is essential in risk assessment and for the effective prevention of work-related musculoskeletal disorders. However, it is unclear whether the subjective ratings of workers and observers correlate to corresponding objective technical measures of exposure. Fifty-nine workers were video recorded while performing a hand-intensive work task at their workplace. Self-ratings of hand activity level (HAL) and force (Borg CR10) using the Hand Activity Threshold Limit Value^® were assessed. Four ergonomist observers, in two pairs, also rated the hand activity and force level for each worker from video recordings. Wrist angular velocity was measured using inertial movement units. Muscle activity in the forearm muscles flexor carpi radialis (FCR) and extensor carpi radialis (ECR) was measured with electromyography root mean square values (RMS) and normalized to maximal voluntary electrical activation (MVE). Kendall's tau-b correlations were statistically significant between self-rated hand activity and wrist angular velocity at the 10th, 50th, and 90th percentiles (0.26, 0.31, and 0.23) and for the ratings of observers (0.32, 0.41, and 0.34). Significant correlations for force measures were found only for observer-ratings in five of eight measures (FCR 50th percentile 0.29, time > 10%MVE 0.43, time > 30%MVE 0.44, time < 5% -0.47) and ECR (time > 30%MVE 0.26). The higher magnitude of correlation for observer-ratings suggests that they may be preferred to the self-ratings of workers. When possible, objective technical measures of wrist angular velocity and muscle activity should be preferred to subjective ratings when assessing risks of work-related musculoskeletal disorders.

Ratings of Hand Activity and Force Levels among Women and Men Who Perform Identical Hand-Intensive Work Tasks

We compared hand activity and force ratings in women and men doing identical hand-intensive work tasks. Musculoskeletal disorders are more common in women and hand-intensive work leads to an increased risk of these disorders. Knowledge of the gender influence in the rating of work exposure is lacking. The aim of this study was to investigate whether women and men performing identical hand-intensive work tasks were equally rated using hand activity and normalized peak force levels with the Hand Activity Threshold Limit Value^®. Fifty-six workers participated, comprising 28 women-men pairs. Four observers-two woman-man pairs-were also involved. Self-ratings and observers' ratings of hand activity and force level were collected. The results of these ratings showed no significant gender differences in self-rated hand activity and force, as well as observer-rated hand activity. However, there was a significant gender difference in the observer-rated force, where the women were rated higher (mean (SD): women 3.9 (2.7), men 3.1 (1.8) (p = 0.01)). This difference remained significant in the adjusted model (p = 0.04) with grip strength and forearm-finger anthropometrics. The results provide new insights that observers' estimates of force can be higher in women compared with men in the same work tasks. Force should be further investigated and preferably compared to objective measurements.

Patient expectations about a clinical diagnostic test may influence the clinician's test interpretation

BACKGROUND

With medical information widely available, patients often have preconceived ideas regarding diagnostic procedures and management strategies.

OBJECTIVES

To investigate whether expectations, such as beliefs about the source of symptoms and knowledge about diagnostic tests, influence pain perception during a clinical diagnostic test.

DESIGN

Cross-sectional study.

METHODS

Pain was induced by intramuscular hypertonic saline infusion in the thenar muscles. In line with sample size calculations, fifteen participants were included. All participants received identical background information regarding basic median nerve biomechanics and basic concepts of differential diagnosis via mechanical loading of painful structures. Based on different explanations about the origin of their induced pain, half of the participants believed (correctly) they had 'muscle pain' and half believed (incorrectly) they had 'nerve pain'. Pain intensity and size of the painful area were evaluated in five different positions of the median nerve neurodynamic test (ULNT1 _MEDIAN). Data were analysed with two-way analyses of variance.

RESULTS

/findings: Changes in pain in the ULNT1 _MEDIAN positions were different between the 'muscle pain' and 'nerve pain' group (p < 0.001). In line with their expectations, the 'muscle pain' group demonstrated no changes in pain throughout the test (p > 0.38). In contrast, pain intensity (p ≤ 0.003) and size of the painful area (p ≤ 0.03) increased and decreased in the 'nerve pain' group consistent with their expectations and the level of mechanical nerve loading.

CONCLUSION

Pain perception during a clinical diagnostic test may be substantially influenced by pain anticipation. Moreover, pain was more aligned with beliefs and expectations than with the actual pathobiological process.

Building COPD care on shaky ground: a mixed methods study from Swedish primary care professional perspective

Background

Chronic obstructive pulmonary disease (COPD) is a public health problem. Interprofessional collaboration and health promotion interventions such as exercise training, education, and behaviour change are cost effective, have a good effect on health status, and are recommended in COPD treatment guidelines. There is a gap between the guidelines and the healthcare available to people with COPD.

The aim of this study was to increase the understanding of what shapes the provision of primary care services to people with COPD and what healthcare is offered to them from the perspective of healthcare professionals and managers.

Methods

The study was conducted in primary care in a Swedish county council during January to June 2015. A qualitatively driven mixed methods design was applied. Qualitative and quantitative findings were merged into a joint analysis. Interviews for the qualitative component were performed with healthcare professionals (n = 14) from two primary care centres and analysed with qualitative content analysis. Two questionnaires were used for the quantitative component; one was answered by senior managers or COPD nurses at primary care centres (n = 26) in the county council and the other was answered by healthcare professionals (n = 18) at two primary care centres. The questionnaire data were analysed with descriptive statistics.

Results

The analysis gave rise to the overarching theme building COPD care on shaky ground. This represents professionals driven to build a supportive COPD care on ‘shaky’ organisational ground in a fragmented and non-compliant healthcare organisation. The shaky ground is further represented by uninformed patients with a complex disease, which is surrounded with shame. The professionals are autonomous and pragmatic, used to taking responsibility for their work, and with limited involvement of the management. They wish to provide high quality COPD care with interprofessional collaboration, but they lack competence and are hindered by inadequate routines and lack of resources.

Conclusions

There is a gap between COPD treatment guidelines and the healthcare that is provided in primary care. To facilitate implementation of the guidelines several actions are needed, such as further training for professionals, additional resources, and improved organisational structure for interprofessional collaboration and patient education.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-017-2393-y) contains supplementary material, which is available to authorized users.

Symptoms of Musculoskeletal Disorders among Drivers of All-Terrain Vehicles in Northern Sweden

All-terrain vehicles (ATVs) are a group of machines that do not operate on prepared roads. Off-road use of these fast-moving machines results in the driver being exposed to high magnitudes of vibration and shock. It is estimated that there are up to 20,000 people in Sweden that uses ATVs during their work, such as forest machines, snowmobiles, snowgroomers, motorcycles, and three- and four-wheeled vehicles. The aim of this cross-sectional study was to investigate the risk for musculoskeletal symptoms of the neck, shoulders, upper and lower back among professional drivers of ATVs. Data from 215 male drivers of forest machines, 137 drivers of snowmobiles, 79 drivers of snowgroomers and 167 men randomly selected from the general population to act as a control group were collected. All subjects were from the four most northern counties in Sweden. Musculoskeletal symptoms during the previous year were assessed using the standardised Nordic questionnaire. Prevalence rate ratios were adjusted for age, smoking and job strain. Results showed that all driver categories had significantly increased prevalence rate ratios (1.5-2.9) for experiencing symptoms in the neck-shoulder and thoracic regions. Unlike findings from previous epidemiological studies, there was not an increased risk of low back pain among any of the driver categories compared to the control group. The higher prevalence of musculoskeletal problems is thought to be due to long-term exposure to physical factors, such as, whole-body vibration (WBV) and shock, static muscle overload and extreme body postures. The findings in this study highlight the fact that working with ATVs may cause, aggravate or prevent resolution of musculoskeletal symptoms. However, the exact cause of these problems is unclear and the interaction between vibration and body posture is not known. The authors believe however that it is necessary to reduce exposure to WBV and shock to decrease the high prevalence of musculoskeletal symptoms among professional ATV drivers. This may be done by implementing preventative measures, such as selecting the best vehicle model or seat, optimising driving style and minimizing use in rough terrain. Health surveillance seems to be important for people that regularly use ATVs in their work.

Physical Activity Levels Among Adolescent and Young Adult Women and Men with and without Intellectual Disability

BACKGROUND

As physical activity can prevent overweight and promote general health, the aim was to investigate the amount of physical activity among adolescent and young adult women and men with intellectual disability (ID), compared to age-matched control groups without intellectual disability. A further aim was to examine whether physical activity level was associated with the body mass index (BMI).

MATERIALS AND METHODS

Fifty-two adolescent and young adult women and men with intellectual disability and 48 without intellectual disability, between the ages 16 and 20 years, BMIs ranging from 16.3 to 50.3 kg/m(2) , were measured for number of steps taken with a pedometer for five consecutive days (Sunday-Thursday).

RESULTS

The only group to meet recommendations regarding number of steps (10 000-12 000/day) was women without intellectual disability. No significant associations were found between total number of steps taken and BMI.

CONCLUSION

As the majority of adolescents and young adults with intellectual disability, especially women, did not reach recommended activity levels regardless of their BMIs, this call for broad measures to increase physical activity.

Seated postural neck and trunk reactions to sideways perturbations with or without a cognitive task

Driving on irregular terrain will expose the driver to sideways mechanical shocks or perturbations that may cause musculoskeletal problems. How a cognitive task, imposed on the driver, affects seated postural reactions during perturbations is unknown. The aim of the present study was to investigate seated postural reactions in the neck and trunk among healthy adults exposed to sideways perturbations with or without a cognitive task. Twenty-three healthy male subjects aged 19-36 years, were seated on a chair mounted on a motion system and randomly exposed to 20 sideways perturbations (at two peak accelerations 5.1 or 13.2m/s(2)) in two conditions: counting backwards or not. Kinematics were recorded for upper body segments using inertial measurement units attached to the body and electromyography (EMG) was recorded for four muscles bilaterally in the neck and trunk. Angular displacements (head, neck, trunk and pelvis) in the frontal plane, and EMG amplitude (normalised to maximum voluntary contractions, MVC) were analysed. The cognitive task provoked significantly larger angular displacements of the head, neck and trunk and significantly increased EMG mean amplitudes in the upper neck during deceleration, although 10% of MVC was never exceeded. A cognitive task seems to affect musculoskeletal reactions when exposed to sideways perturbations in a seated position.

Telehealthcare in COPD: a systematic review and meta-analysis on physical outcomes and dyspnea

BACKGROUND

Only a minority of patients with chronic obstructive pulmonary disease (COPD) have access to pulmonary rehabilitation (PR). Home-based solutions such as telehealthcare, have been used in efforts to make PR more available. The aim of this systematic review was to investigate the effects of telehealthcare on physical activity level, physical capacity and dyspnea in patients with COPD, and to describe the interventions used.

METHODS

Randomized controlled trials were identified through database searches, reference lists and included authors. Articles were reviewed based on eligibility criteria by three authors. Risk of bias was assessed by two authors. Standardized mean differences (SMD) or mean differences (MD) with 95% CI were calculated. Forest plots were used to present data visually.

RESULTS

Nine studies (982 patients) were included. For physical activity level, there was a significant effect favoring telehealthcare (MD, 64.7 min; 95% CI, 54.4-74.9). No difference between groups was found for physical capacity (MD, -1.3 m; 95% CI, -8.1-5.5) and dyspnea (SMD, 0.088; 95% CI, -0.056-0.233). Telehealthcare was promoted through phone calls, websites or mobile phones, often combined with education and/or exercise training. Comparators were ordinary care, exercise training and/or education.

CONCLUSIONS

The use of telehealthcare may lead to improvements in physical activity level, although the results should be interpreted with caution given the heterogeneity in studies. This is an important area of research and further studies of the effect of telehealthcare for patients with COPD would be beneficial.

REGISTRATION

In PROSPERO 2012: CRD42012003294.

STUDY PROTOCOL

http://www.crd.york.ac.uk/PROSPEROFILES/3294_PROTOCOL_20121016.pdf.

Postural muscle responses and adaptations to backward platform perturbations in young people with and without intellectual disability

This study examines postural muscle responses to backward perturbations in young people (16-20 years) with and without intellectual disability (ID). The study included 56 young people with ID and 43 age-matched without ID volunteers. The subjects stood on a platform that was moved backwards in a surface translation. Lower and upper leg muscles and lower back spine muscles were recorded with surface electromyography (EMG). Muscle onset latency, time to peak amplitude (EMG), adaptation of muscle responses to repeated perturbations (using integrated EMG (IEMG) for epochs), and synergies and strategies were assessed. The result showed no differences between the two groups in muscle onset latency, synergies, and strategies. Young people with ID reduced their time to peak amplitude in investigated muscles, a response that was different from the group without ID. Also, young people with ID tended to adapt their IEMG less compared to the controls. These findings suggest that young people with ID have limited ability to use somatosensory information and adapt their postural muscle responses to repeated external perturbations.

Adolescents with intellectual disability have reduced postural balance and muscle performance in trunk and lower limbs compared to peers without intellectual disability

For adolescent people with ID, falls are more common compared to peers without ID. However, postural balance among this group is not thoroughly investigated. The aim of this study was to compare balance and muscle performance among adolescents aged between 16 and 20 years with a mild to moderate intellectual disability (ID) to age-matched adolescents without ID. A secondary purpose was to investigate the influence of vision, strength, height and Body Mass Index (BMI) on balance. A group of 100 adolescents with ID and a control group of 155 adolescents without ID were investigated with five balance tests and three strength tests: timed up and go test, one leg stance, dynamic one leg stance, modified functional reach test, force platform test, counter movement jump, sit-ups, and Biering-Sørensen trunk extensor endurance test. The results showed that adolescents with an ID in general had significantly lower scores in the balance and muscle performance tests. The group with ID did not have a more visually dominated postural control compared to the group without ID. Height, BMI or muscle performance had no strong correlations with balance performance. It appears as if measures to improve balance and strength are required already at a young age for people with an ID.

Neck pain combined with arm pain among professional drivers of forest machines and the association with whole-body vibration exposure

The purpose of this study was to investigate the existence of neck pain and arm pain among professional forest machine drivers and to find out if pain were related to their whole-body vibration (WBV) exposure. A self-administered questionnaire was sent to 529 forest machine drivers in northern Sweden and the response was 63%. Two pain groups were formed; 1) neck pain; 2) neck pain combined with arm pain. From WBV exposure data (recent measurements made according to ISO 2631-1, available information from reports) and from the self-administered questionnaire, 14 various WBV exposure/dose measures were calculated for each driver. The prevalence of neck pain reported both for the previous 12 months and for the previous 7 d was 34% and more than half of them reported neck pain combined with pain in one or both arms. Analysis showed no significant association between neck pain and high WBV exposure; however, cases with neck pain more often experienced shocks and jolts in the vehicle as uncomfortable. There was no significant association between the 14 WBV measures and type of neck pain (neck pain vs. neck pain combined with arm pain). It seems as if characteristics of WBV exposure can explain neither existence nor the type of neck pain amongst professional drivers of forest machines. The logging industry is important for several industrialised countries. Drivers of forest machines frequently report neuromusculoskeletal pain from the neck. The type of neck pain is important for the decision of treatment modality and may be associated with exposure characteristics at work.

Hand-arm vibration syndrome (HAVS) and musculoskeletal symptoms in the neck and the upper limbs in professional drivers of terrain vehicles--a cross sectional study

This study compares the prevalence of symptoms of Hand-arm vibration syndrome (HAVS) and musculoskeletal symptoms in the neck and the upper limbs, between professional drivers of terrain vehicles and a referent group. 769 male professional drivers of forest machines, snowmobiles, snowgroomers and reindeer herders and 296 randomly selected male referents completed a questionnaire about symptoms of HAVS and musculoskeletal symptoms in the neck and the upper limbs. They also gave information about their lifetime exposure duration driving terrain vehicles and their nicotine use. Prevalence odds ratios (POR) were determined and adjusted for age and nicotine use. Results show that there is a relation between exposure to driving terrain vehicles and some of the symptoms of HAVS (POR: 1.2-6.1). Increased odds of musculoskeletal symptoms in neck, shoulders and wrists were also found (POR 1.2-6.4), and it seemed to be related to the cumulative exposure time.

Effects on leg muscular performance from whole-body vibration exercise: a systematic review

The purpose of this study was to investigate the effects on leg muscular performance from whole-body vibration exercise. Literature search was performed on the databases Pubmed, Cinahl, ISI web of science (Sci-expanded, SSCI) and Embase (Rehab & Physical Med). Rating of 19 relevant studies was performed (14 on long-term exercise and five on short-term exercise) using a score system for the methodological quality. Several randomized-controlled trial studies of high to moderate quality show similar improvements from long-term regimen on muscular performance in the legs after a period of whole-body vibration exercise. As there were few studies on short-term exercise and as they had no control groups, the same convincing improvements regarding muscular performance were not achieved. Preliminarily, there is strong to moderate evidence that long-term whole-body vibration exercise can have positive effects on the leg muscular performance among untrained people and elderly women. There is no clear evidence for effects on muscular performance after short-term vibration stimuli.

Whole-Body Vibration Exposure and Non-neutral Neck Postures During Occupational Use of All-terrain Vehicles

OBJECTIVES

The purpose of this study was to characterize whole-body vibration (WBV) exposure from various all-terrain vehicles (ATVs) like snowgroomers, snowmobiles and forwarders, and to investigate how frequently the drivers' cervical spine is positioned in a non-neutral rotational position during operation.

METHODS

Field measurements of WBV were measured according to the international standard ISO 2631-1 in 19 ATVs. Simultaneous recordings of frequency and duration of rotational neck movements exceeding 15 degrees were achieved through an observational method, PEOflex.

RESULTS

The sum of the vectors of frequency-weighted r.m.s. acceleration varied between 0.5 and 3.5 m s(-2), which meant that for most vehicles they exceeded the action value stated by the European Union (0.5 m s(r.m.s.)(-2)). In general, snowmobiles achieved the highest vibration total value. The dominant vibration direction for the snowmobile was the x-axis but the z-axis also had relatively high vibration dose values and maximal transient vibration values. The z-axis was the dominant vibration direction for the snowgroomer and the y-axis for the forwarder. Frequency and duration of non-neutral rotational neck postures were relatively low for all driver categories.

CONCLUSIONS

Vibration magnitudes in ATVs are considerably high than the EU's action value and the health guidance caution zones in ISO 2631-1. The dominant vibration direction varies depending on the machine type. Duration and frequency of non-neutral rotational positions do not seem to constitute single ergonomic risk factors for musculoskeletal symptoms in the neck among professional drivers of ATVs. However, synergistic effects with other factors are conceivable.

Osteoarthritis in the hip and whole-body vibration in heavy vehicles

BACKGROUND

Farmers have an increased risk of osteoarthritis in the hip, but the mechanism is not known. It has been suggested that the driving of tractors and jumping up and down from the tractor cabin is of importance. In this study, we test the hypothesis that driving vehicles with high levels of whole-body vibration (WBV) is associated with an increased risk of osteoarthritis in the hip.

METHODS

This is a cohort study of male operators of heavy vehicles working in the construction industry. They participated in a national health control program. The incidence rate for joint replacement in the hip was found in the Swedish Hospital Discharge Register for 1987 to 1998 and compared with the incidence in reference groups. Their exposure to WBV was estimated from their job titles. The rates were adjusted to body mass index (BMI) and smoking habits and compared to referents participating in the same health control program.

RESULTS

Drivers exposed to WBV had not an increased risk of joint replacement due to osteoarthritis in the hip (RR = 0.82; 95% CI 0.51-1.24).

CONCLUSIONS

This study does not support the hypothesis that exposure to WBV during operating a vehicle cause an increased risk of osteoarthritis in the hip.

Neuromusculoskeletal disorders in the neck and upper extremities among drivers of all-terrain vehicles--a case series

BACKGROUND

The purpose of this study was to investigate whether professional drivers of all-terrain vehicles (ATVs) with neck pain have a different array of neuromusculoskeletal disorders in the neck and upper extremities than a referent group with neck pain from the general population. It is hypothesized that exposure to shock-type vibration and unfavorable working postures in ATVs have the capacity to cause peripheral nervous lesions.

METHODS

This study was based on a case series analyzed according to a case-case comparison design. The study population consisted of 60 male subjects, including professional drivers of forest machines (n = 15), snowmobiles (n = 15), snowgroomers (n = 15) and referents from the general population (n = 15) all of whom had reported neck pain in a questionnaire and underwent an extensive physical examination of the neck and upper extremities. Based on symptom history, symptoms and signs, and in some cases chemical, electroneurographical and radiological findings, subjects were classified as having a nociceptive or neuropathic disorder or a mix of these types.

RESULTS

The occurrence of asymmetrical and focal neuropathies (peripheral nervous lesion), pure or in a mix with a nociceptive disorder was common among cases in the ATV driver groups (47%-79%). This contrasted with the referents that were less often classified as having asymmetrical and focal neuropathy (27%), but instead had more nociceptive disorders. The difference was most pronounced among drivers of snowgroomers, while drivers of forest machines were more frequently classified as having a nociceptive disorder originating in the muscles.

CONCLUSION

This study found a high prevalence of assymetrical and focal neuropathies among drivers with pain in the neck, operating various ATVs. It seems as if exposure to shock-type whole-body vibration (WBV) and appurtenant unfavorable postures in ATVs may be associated to peripheral nervous lesions.

Different toxic, fibrogenic and mutagenic effects of four commercial quartz flours in the rat lung

There is still intensive debate on the variability in the biological activities of different quartz species. Therefore we examined in a rat lung model the inflammatory, fibrogenic and genotoxic characteristics of four commercial quartz flours. The samples, two with probably low activity and two with probably high activity were selected from a panel of 16 samples on the basis of in vitro investigations. Rats were exposed by a single intratracheal injection of 0.6, 1.2 and 2.4 mg quartz samples per lung or with 1.2 mg standard quartz DQ12. After 90 days the inflammatory response was measured in the bronchoalveolar lavage fluid, as well as the content of 8-oxoguanine in the DNA of the lung cells. Additionally mutated p53 protein was determined. The four quartz samples revealed specific differences in all parameters investigated. In good agreement with the in vitro results the two samples expected as lowly active showed only weak inflammatory and no genotoxic reactions in the rat lungs. In contrast the two samples suspected as highly reactive induced a pronounced inflammatory response and for one of the samples genotoxic effects could be proven. The results raised here show a broad spectrum of biological activities dependent on the type of quartz from almost inert to genotoxic and highly inflammatory.

Investigations on the inflammatory and genotoxic lung effects of two types of titanium dioxide: untreated and surface treated

TiO(2) is considered to be toxicologically inert, at least under nonoverload conditions. To study if there are differences in lung effects of surface treated or untreated TiO(2) we investigated the inflammatory and genotoxic lung effects of two types of commercially available TiO(2) at low doses relevant to the working environment. Rats were exposed by instillation to a single dose of 0.15, 0.3, 0.6, and 1.2 mg of TiO(2) P25 (untreated, hydrophilic surface) or TiO(2) T805 (silanized, hydrophobic surface) particles, suspended in 0.2 ml of physiological saline supplemented with 0.25% lecithin. As control, animals were instilled with the vehicle medium only or with a single dose of 0.6 mg quartz DQ12. At days 3, 21, and 90 after instillation bronchoalveolar lavage was performed and inflammatory signs such as cells, protein, tumor necrosis factor-alpha, fibronectin, and surfactant phospholipids were determined. Additionally, 8 microm frozen sections of the left lobe of the lung were cut and stored at -80 degrees C. The sections were used for immunohistochemical detection of 8-oxoguanine (8-oxoGua) by a polyclonal antibody in the DNA of individual lung cells. In the quartz-exposed animals a strong progression in the lung inflammatory response was observed. Ninety days after exposure a significant increase in the amount of 8-oxoGua in DNA of lung cells was detected. In contrast, animals exposed to TiO(2) P25 or TiO(2) T805 showed no signs of inflammation. The amount of 8-oxoGua as a marker of DNA damage was at the level of control. The results indicate that both types of TiO(2) are inert at applicated doses.

Quartz exposure of the rat lung leads to a linear dose response in inflammation but not in oxidative DNA damage and mutagenicity

Exposure to quartz and high concentrations of other poorly soluble particles can lead to the development of lung tumors in the rat. The mechanisms involved in particle-induced carcinogenesis seem to include inflammation-associated production of reactive oxygen species (ROS) and DNA damage. ROS induce 8-oxoguanine (8-oxoGua) and a panel of other oxidation products in DNA. In proliferating cells such DNA lesions can lead to various types of mutations, which might be critical for cancer-related genes with respect to tumor formation. Quartz is known to mediate the induction of 8-oxoGua in the nuclear DNA of lung cells when applied to the lung of rats. We have investigated the time- and dose-dependent biologic effects of quartz and, as a control, corundum, on cell proliferation and various pulmonary inflammation and toxicity markers in rat bronchoalveolar lavage fluid (BALF); on the induction of 8-oxoGua in the DNA of rat lung cells; and on the cellular levels of p53 wild-type and p53 mutant (mut) protein. Rats were exposed by intratracheal instillation to various amounts of quartz (0.3, 1.5, or 7.5 mg/rat) or corundum (0.3, 1.5, or 7.5 mg/rat) and measured at Days 7, 21, and 90 after exposure. Corundum had no adverse effects except a slight elevation of 8-oxoGua at a dose of 7.5 mg/rat. However, significant changes in the BALF were detected at all quartz doses. 8-oxoGua was significantly increased only at 1.5 and 7.5 mg quartz/rat. The amount of cells with detectable p53 wild-type protein levels was increased at 1.5 and 7.5 mg quartz/rat at 7 and 21 d. Elevated amounts of cells with enhanced p53 mut protein levels were measured at all time points after instillation of 7.5 mg quartz/rat.

Light and electron microscopic investigation of the lectin-binding pattern in the oxyntic gland region of bovine abomasum

For the first time the expression of glycoconjugate residues in the oxyntic gland region of bovine abomasum has been investigated by means of lectin histochemistry. For light microscopic investigations, a battery of ten lectins, Con A, PSA, UEA I, WGA, LEA, SNA, RCA120, MPA, DBA and SBA was used. For electron microscopic examinations, WGA and RCA120 were utilized. The staining pattern of the lectins in all exocrine cell types of the oxyntic gland region is described. Compared to the results of monogastric species our study reveals some similarities, but just as many differences in the composition of glycoconjugate residues in bovine exocrine cell types. Typical for surface mucous cells is the amount of L-fucose, N-acetyl glucosamine residues and Galbeta1, 4GlcNAc sequences in the secretory granules. SNA could serve as a marker for surface mucous cells, because this lectin exclusively stains the plasma membrane and the secretory granules of surface mucous cells and the extracellular mucus. L-fucose and N-acetyl glucosamine are typical for the secretory granules of mucous neck cells. In addition, the secretory granules show the highest amount of N-acetyl galactosamine residues of all exocrine cells, so that DBA and SBA are recommended as marker lectins for mucous neck cells. Most lectins strongly stain the intracellular membrane system of oxyntic cells. The cocktail of glycoconjugates in the vicinity of the HCI production site provide protection against chemical injury. In chief cells only the apical plasma membrane is more or less labeled with all lectins apart from SNA. Specific marker lectins for oxyntic cells or chief cells of the bovine have not been characterized.

Significant differences in the cellular and molecular reactions of rat and hamster lung after quartz exposure

Exposure of rats to high doses of quartz and other insoluble isometric particles can produce lung tumors. In contrast, after exposure of such particles in hamsters no tumor outcome has been observed. Recent studies have demonstrated that the tumorigenic effect of particles is closely linked to the induction of inflammatory processes and the subsequent formation and persistence of mutagenic oxidative DNA-modifications. Species-specific differences in sensitivity to particles should therefore be reflected in the molecular reaction of the lung cells. We exposed rats and hamsters to two different doses of quartz (0.3 mg, 1.2 mg/100 g body weight) by intratracheal instillation and characterized the dose-related pattern of pulmonary inflammation (neutrophil recruitment, TNF), toxicity (protein content, surfactant phospholipids), antioxidant defence (glutathione content), mutagenicity (8-oxoguanine, p53) and proliferation. Our results clearly demonstrate a significantly higher response of the rat to quartz exposure for all determined molecular and cellular parameters. Therefore the examination of these parameters in humans would contribute to the evaluation of the relevance of rats or hamsters as models to predict particle-induced human lung cancer risk.

Evidence of a no-effect level in silica-induced rat lung mutagenicity but not in fibrogenicity

Exposure to silica can lead to fibrosis and the development of lung tumors in the rat. Based on these animal studies and on epidemiological data, silica has been classified as a human carcinogen. The initial mechanisms have not been finally clarified, but particle-induced tumor formation is at least closely associated with inflammation, the production of reactive oxygen species (ROS) and DNA damage. We investigated the dose-dependent effects of silica on the formation of the major DNA oxidation product 8-oxoguanine (8-oxo-Gua) in rat lung cells, on p53 (p53) and p53 mutant protein (p53 mut) synthesis, as well as on the amount of the surfactant phospholipids phosphatidylinositol (PI) and phosphatidylglycerol (PG) in the bronchoalveolar lavage fluids (BALF) as indicators of fibrotic processes in the lung. Rats were exposed by intratracheal instillation to various amounts of DQ12 quartz (0.15, 0.3, 0.6, 1.2, 2.4 mg/animal) and lungs were investigated after 21 and 90 days. PG decreased and PI increased quartz dose dependently. 8-oxoGua was significantly increased only after 1.2 and 2.4 mg quartz/animal. Cells expressing p53 protein were increased at 1.2 and 2.4 mg, p53 mutant protein only at 2.4 mg/animal. This indicates a no-effect level for mutagenicity at a low, but still fibrogenic quartz exposure.

Biomarkers of genetic damage and inflammation in blood and bronchoalveolar lavage fluid among former German uranium miners: a pilot study

Former East German uranium miners who are known to have been exposed to radon are estimated to be at high risk for lung carcinogenesis. Among these miners over 200 occupationally caused lung cancer cases are expected to occur each year, resulting in a total of 7,000-24,000 excess lung cancer cases in the coming years. It is still unknown whether there is a correlation between biomarkers and the exposure of the uranium miners to ionizing radiation that might enable us to trace those miners with high lung cancer risk. The primary aim of this pilot study was to test the possibility of performing a biomarker study in this unique cohort of former uranium miners in spite of several limitations that had to be taken into consideration when comparing them with healthy controls, such as old age, age-dependent diseases and potential confounding artefacts from dissimilar smoking patterns. The second aim was to test a range of biomarkers for DNA damage and inflammation in leukocytes and bronchoalveolar fluid for their ability to detect biological effects. In this cohort of miners we found an increased frequency of chromosomal aberrations in blood lymphocytes and an increased prevalence of both fibronectin and tumour necrosis factor alpha in the bronchoalveolar fluid.

Formation and persistence of 8-oxoguanine in rat lung cells as an important determinant for tumor formation following particle exposure

Exposure of rats to quartz (or various other particles) can lead to the development of lung tumors. At the moment, the mechanisms involved in particle-induced tumor formation are not clarified. However, it is suggested that inflammation, in conjunction with the production of reactive oxygen species (ROS) and an enhancement of epithelial cell proliferation, may play a key role in the development of lung tumors. ROS induces 8-oxoguanine (8-oxoGua) and other mutagenic DNA oxidation products, which can be converted to mutations in proliferating cells. Mutation formation in cancer-related genes is a critical event with respect to tumor formation. In this study we investigated the effects of quartz (DQ12) and of the nontumorigenic dust corundum on the induction of 8-oxoGua in the DNA of rat lung cells, as well as on cell proliferation and pulmonary inflammation. Wistar rats were exposed by intratracheal instillation to quartz (2.5 mg/rat) or corundum (2.5 mg/rat) suspended in physiological saline; control animals exposed to physiological saline or left untreated. Measurements were carried out 7, 21, and 90 days after the exposures. 8-oxoGua levels were determined in lung tissue sections at the single cell level by immunocytological assay using a rabbit anti-8-oxoGua antibody. After exposure to quartz, 8-oxoGua levels were significantly increased at all time points of investigation. Additionally, we observed inflammation and an enhanced cell proliferation. Exposure to corundum had no adverse effects on the lung; neither increased 8-oxoGua levels nor enhanced cell proliferation or inflammation were detected. These observations support the suggestion that inflammation associated with increased 8-oxoGua levels in lung cells and increased cell proliferation is an important determinant for particle-induced development of lung tumors in the rat.

Silicotic lymph node reactions in mice: genetic differences, correlation with macrophage markers, and independence from T lymphocytes

Quartz was injected into a hind food of BALB/c and DBA/2 mice and on days 40, 90, and 180 the progressive response ensuing in the draining popliteal lymph node (PLN) was investigated by histopathology and immunohistopathology. The area of silicotic nodules (ASN) was measured by morphometry, and, by this parameter, strain BALB/c proved to be a high responder to quartz, and strain DBA/2 a low responder, albeit both strains showed a similar degree of reactive lymphoid hyperplasia in the draining PLN. Both strains also showed a similar quartz content in the draining PLN but in BALB/c mice quartz particles were concentrated in the ASN, whereas in DBA/2 mice they were evenly dispersed over the PLN. Because the silicotic response of athymic BALB/c nu/nu mice was even stronger than that of euthymic BALB/c mice, T cells are not required for the development of silicotic nodules. This fits the notion that quartz is not an antigen and that high and low responder strains are MHC-identical. Because quartz-treated BALB/c, but not DBA/2 mice, showed a persistent expression of the macrophage differentiation markers MRP8 and MRP14, phenotypically the observed strain difference in silicotic responsiveness seems to be expressed at the level of macrophages.

Age-dependency of surfactant phospholipids and surfactant protein A in bronchoalveolar lavage fluid of children without bronchopulmonary disease

Whilst alterations in surfactant components of bronchoalveolar lavage fluid (BALF) have been described in a variety of pulmonary diseases in adults, no information is available on the surfactant composition in children beyond the neonatal period. In order to obtain reference values for the paediatric age group, we have studied phospholipid profiles of BALF in children without pulmonary disease. The study population consisted of 38 children aged 3-15 yrs (mean +/- SD 8 +/- 4 yrs) undergoing elective surgery for nonpulmonary illnesses. Surfactant composition was analysed by high pressure liquid chromatography using both an ultraviolet and a light-scattering detector. Total phospholipid concentration was higher in children under 8 yrs of age and decreased with age. In contrast, the total protein concentration remained constant throughout the age range. No age-related changes in the relative composition of phospholipid fractions could be observed. Surfactant protein A concentrations were highly variable in all age groups. This study provides the first data on surfactant components in bronchoalveolar lavage fluid of healthy children and will be the basis for future studies of children with pulmonary diseases.

Advantages of Sirius Red staining for quantitative morphometric collagen measurements in lungs

Sirius Red staining is presented as a method for collagen determination, enabling quantitative morphometric measurements to be performed in locally defined tissue areas. The advantage of this method is especially shown for alveolar lung tissue. By excluding the bronchial areas in the tissue sections, the differences in the degree of fibrosis proved to be more discrete after different loads of quartz dust than by any other method. The difference of 12 micrograms collagen measured colorimetrically represented a 1.2-fold increase. The collagen measured in the alveolar tissue by the morphometric method rose from 9.8 to 28.6%. This is a 2.9-fold increase, underlining the vast improvement in sensitivity. Thus, this method is specifically suitable for the evaluation of very small fibrotic lesions. The quartz doses given are particularly low compared to most other investigations. Histologic lung and lymph node sections from female Wistar rats injected intratracheally with differing quantities of quartz dust (0.03, 0.1, 0.5, 1.75 mg) were stained with Sirius Red, and the collagen fibers measured with a quantitative image analysis. The results for lymph nodes using different methods (wet weight determination, quantitative measurement of quartz typical areas, colorimetric and morphometric collagen determination) showed a high correlation at the different doses. This showed that the morphometric method is suitable for the quantitative measurement of collagen. Corresponding results were also found in the comparative lung tissue measurements (colorimetric and morphometric collagen determination). However, the morphometric method has the decisive advantage that measurements can be restricted to defined tissue areas and do not destroy the section.

Toxicological investigations on silicon carbide. 2. In vitro cell tests and long term injection tests

Silicon carbide (SiC) dust and other dusts for comparison were injected intratracheally at a high dose (50 mg) into rats and the response of the lungs and the lymph nodes was studied after an appropriate experimental period. The indices studied were: histological changes in the lung and lymph nodes, organ weights, the formation of collagenous fibres, and the appearance of quartz typical areas. According to several epidemiological investigations and previous experimental animal studies, SiC produces silicogenic (fibrogenic) effects. No changes in the tissues studied in terms of damaging fibrogenic effects could be found after eight months (first series) and three and 12 months (second series). In particular, the histological findings and the absence of quartz typical areas as well as the quantitative determination of collagen fibres show that SiC had no harmful effects on tissues. Based on these results, the extent to which other exposures during the production of SiC can be responsible for the established radiological alterations is discussed. Without doubt the following may be confounders: SiC fibres, crystalline SiO2 (quartz, cristobalite, tridymite), and possibly gaslike emissions (SO2). From the hygienic medical point of view the workplaces during SiC manufacture should be examined carefully. The substance SiC dust as such can be considered as inert from the experimental results based on qualitative and extremely sensitive procedures. A revision of the present threshold value for SiC in ther German MAK list is called for.

Toxicological investigations on silicon carbide. 1. Inhalation studies

The question of lung damage as a result of exposure to silicon carbide (SiC) was investigated by inhalation experiments to obtain information on the qualitative response of lung tissue to the test substance (SiC). For comparison, quartz, kaolinite, and tempered clay dusts were used. The indices for the effects of the dusts studied were organ weights, numbers of bronchoalveolar cells, lung surfactant phospholipid concentrations including subfractions, and lung clearance. Exposure to the test samples was carried out according to the Essen inhalation model in two independent series. The results of the two series were similar: Compared with sham controls, exposure to SiC did not affect the indices studied. Even at a low dose (a quarter of the SiC dose) quartz gave pronounced deviations in all indices. In particular, an increase in granulocytes indicated toxic properties of the dust. The long term elimination of quartz from the lung was worse than that of SiC. The kaolinite and tempered clay dusts were intermediate between SiC and quartz based on several of the indices studied. It is concluded that SiC is deposited practically inert in the lung.

Activity testing of alveolar macrophages and changes in surfactant phospholipids after irradiation in bronchoalveolar lavage: experimental and clinical data

This study presents results of bronchoalveolar lavage (BAL) after irradiation to the lungs in mice as well as clinical data. The number of BAL cells, mainly macrophages, lymphocytes, and granulocytes, changed in a time-dependent manner. The phagocytic activity of the macrophages measured as the phagocytosis of microbeads and measured as the esterase activity also showed a strong time-dependent increase during the acute phase up to 21 days after irradiation. The contents of surfactant phospholipids (SF) and sphingomyelin (SPH; as a parameter for cell death) were quantified by HPLC. Both were significantly changed between day 2 and 21 after irradiation. Three BALs of a patient with idiopathic interstitial pneumonitis, who had received an allogenic bone marrow graft after total body irradiation with 10 Gy, showed similar effects in the cellular and surfactant parameters. These data indicate that there are positive interactions between the number of different BAL cells, macrophage activity, and SF and SPH content in the preclinical model of the mouse as well as in the clinical situation after lung irradiation.

Recovery of rat alveolar macrophages by bronchoalveolar lavage under normal and activated conditions

When rat (female Wistar) lungs were lavaged (bronchoalveolar lavage, BAL) six times with physiological saline, approximately the same number of alveolar macrophages (AM) were found in the first and second BAL, whereas in the third fourth, fifth, and sixth BAL, the number of AM decreased exponentially. Morphometric counting of the number of AM in histological sections of lung tissue showed that only 14% of the AM population had been recovered by BAL. Although additives to the BAL fluid such as lidocaine and/or fetal calf serum increased the AM count in the first washing considerably, the total number of AM washed out remained unaltered. Addition of the phagocytosis stimulant zymosan increased the AM count in BAL by a factor of more than 2. On stimulation of the lungs with an inert dust (silicon carbide), the AM count in the BAL and the lung was only slightly increased 8 weeks after intratracheal instillation. In contrast, after exposure to fibrogenic and cytotoxic quartz, the AM count in BAL and lung was significantly increased, and the recovery of AM had also increased by a factor of approximately 2. The experiments show that it is the micromilieu of the alveoli and the condition of the AM (certain physiological activation states, such as phagocytic activity) that essentially determine the degree of recovery.

Radiation-induced changes in lung tissue and development of fibrosis determined by quantitative morphometric methods

This study presents results of morphometric investigations of mouse lungs after single irradiation. An automatic image analyser was used to monitor pathological changes in morphological structure, especially the size and distribution of collagen fibres, the thickness of the septa and the diameters of alveoli in the lung. Radiation-induced changes in the area of alveoli and septa as well as collagen content were seen 11 weeks after irradiation. A dose-dependent increase in tissue and decrease in alveolar surface as well as a quantifiable increase in radiation oedema were seen. The septa were thickened and the total collagen content increased in a dose-dependent manner. The morphometric methods used here are suitable for determining changes in lung structure, particularly those in collagen content in the early phase of a pathological response after thorax or total body irradiation for conditioning in bone marrow transplantation.

Spine density on olfactory granule cell dendrites is reduced in rats reared in a restricted olfactory environment

The Golgi technique was used to study the development of spines on the external dendrites of granule cells in the olfactory bulbs of young rats that had been continuously exposed to cyclohexanone vapor, deodorized air, or rat odors. Exposure to deodorized air for 3 weeks from postnatal day 1 reduced spine density on the medial and lateral sides of the bulb, whilst exposure to cyclohexanone reduced spine density on the lateral side only. These reductions were evident in other animals exposed for 7 weeks. With all treatments, spine density reached a maximum at postnatal day 21 and decreased markedly during the next month.

Freeze-fracture analysis of the respiratory cilia from the bronchial mucosa of a patient with primary ciliary dyskinesia

Respiratory cilia of the bronchial mucosa from a 5-year-old boy with clinical evidence of classical Kartagener's syndrome (situs inversus, bronchiectasis and sinusitis) were first examined by means of transmission electron microscopy for identification of the axonemal defects described as typical for primary ciliary dyskinesia (PCD). Additional oscillography was performed on the cilia in vitro, which showed absence of a coordinated ciliary beat frequency. After clear classification of the case as PCD, a freeze-fracture examination of the respiratory cilia was performed, which revealed a higher density of intramembrane particles on the outer fracture face (E-face) than on the inner fracture face (P-face). The results were discussed with regard to probable pathogenetic aspects on PCD.

Changes in granule cells of the ferret olfactory bulb associated with imprinting on prey odours

The maturation of the granule cells of the ferret olfactory bulb around the time of odour imprinting has been examined. Rapid Golgi impregnation studies revealed a temporal overshoot in the development of the spines on the external and internal dendrites of the granule cells. In contrast, the number of somatic spines decreased continuously. Electron microscopical examinations of the synaptic contacts in the external plexiform layer revealed that the time course of synapse and reciprocal synapse formation was similar to that of the formation of the spines on the external dendrites. The results were taken as evidence that both the Golgi and the electron microscopical investigations described the same developmental process of postnatal synaptic rearrangement.

Effect of N-methyl-formimino-methylester on the vomeronasal neuroepithelium of mice

N-methyl-formimino-methylester (MFM), a highly volatile chemical substance, causes massive, transient sensory-cell degeneration in the main, but not in the vomeronasal olfactory sensory epithelium of mice. After MFM-treatment it appears possible to study the accessory olfactory system after chemical "deafferentation" of the main system.