Analysis of HSPA1B (+1267A>G) Genetic Polymorphism in Patients with Vibration Disease in Combination with Metabolic Syndrome.

In 167 men with vibration syndrome (VS), allele and genotype frequencies of HSPA1B (+1267A>G) genetic polymorphism (rs1061581) were studied depending on the type of vibration exposure and on the presence or absence of metabolic syndrome (MetS). The examined subjects were divided into two groups: VS patients (n=80) and VS+MetS patients (n=87). The differences in the lipid profiles between groups were revealed against the background of the lack of distinctions in the age of patients for A/G and G/G genotypes carriers. An increase in A/A (p=0.03) and a decrease in A/G (p=0.04) genotype frequencies in VS patients caused by hand-transmitted vibration in comparison with those in whom the disease was caused by a combination of hand-transmitted and whole-body vibration were found. The shifts in the frequencies of the above genotypes (p=0.01) were similar in patients with both types of vibration exposure in the VS+MetS group in comparison with VS group; the carriage of genotypes with the G allele in VS group exceeded that in VS+MetS group (p=0.01).

Riveting hammer vibration damages mechanosensory nerve endings.

Hand-arm vibration syndrome (HAVS) is an irreversible neurodegenerative, vasospastic, and musculoskeletal occupational disease of workers who use powered hand tools. The etiology is poorly understood. Neurological symptoms include numbness, tingling, and pain. This study examines impact hammer vibration-induced injury and recoverability of hair mechanosensory innervation. Rat tails were vibrated 12 min/d for 5 weeks followed by 5 week recovery with synchronous non-vibrated controls. Nerve fibers were PGP9.5 immunostained. Lanceolate complex innervation was compared quantitatively in vibrated vs sham. Vibration peak acceleration magnitudes were characterized by frequency power spectral analysis. Average magnitude (2515 m/s2 , root mean squared) in kHz frequencies was 109 times that (23 m/s2 ) in low Hz. Percentage of hairs innervated by lanceolate complexes was 69.1% in 5-week sham and 53.4% in 5-week vibration generating a denervation difference of 15.7% higher in vibration. Hair innervation was 76.9% in 5-weeks recovery sham and 62.0% in 5-week recovery vibration producing a denervation difference 14.9% higher in recovery vibration. Lanceolate number per complex (18.4 ± 0.2) after vibration remained near sham (19.3 ± 0.3), but 44.9% of lanceolate complexes were abnormal in 5 weeks vibrated compared to 18.8% in sham. The largest vibration energies are peak kHz accelerations (approximately 100 000 m/s2 ) from shock waves. The existing ISO 5349-1 standard excludes kHz vibrations, seriously underestimating vibration injury risk. The present study validates the rat tail, impact hammer vibration as a model for investigating irreversible nerve damage. Persistence of higher denervation difference after 5-week recovery suggests repeated vibration injury destroys the capability of lanceolate nerve endings to regenerate.

[Carpal canal ultrasound examination in patients with mild hand-arm vibration disease].

Objective: To investigate the clinical value of ultrasound examination of carpal canal structure in patients with mild hand-arm vibration disease. Methods: A total of 29 patients (58 wrists) with mild hand-arm vibration disease who were treated in Shenzhen Prevention and Treatment Center for Occupational Diseases from May to December, 2015 were enrolled as observation group, and 20 healthy volunteers (40 wrists) were enrolled as the control group. Color Doppler ultrasound was used to observe the morphology and echo of the median nerve in the carpal canal and 9 muscle tendons and transverse carpal ligament. The thickness of transverse carpal ligament and diameter of the median nerve at the level of the hamulus of hamate bone were measured, as well as the cross-sectional area of the median nerve at the level of pisiform bone. Results: In the 29 patients with hand-arm vibration disease patients in the observation group, 8 experienced entrapment of the median nerve in the carpal canal, among whom 5 had entrapment in both wrists; there were 13 wrists (23%) with nerve entrapment and 45 wrists (77%) without nerve entrapment. Compared with the control group, the patients with hand-arm vibration disease and nerve entrapment in the observation group showed significant thickening of the transverse carpal ligament at the level of the hamulus of hamate bone and a significant increase in the cross-sectional area of the median nerve at the level of pisiform bone (P<0.05) , while there were no significant differences in the thickness of transverse carpal ligament at the level of the hamulus of hamate bone and the cross-sectional area of the median nerve at the level of pisiform bone (t=-9.397 and -4.385, both P>0.05) . Conclusion: Ultrasound examination can clearly show the radiological changes of carpal canal contents in patients with mild hand-arm vibration disease and has a certain diagnostic value in nerve damage in patients with hand-arm vibration disease.

The relationship between clinical and standardized tests for hand-arm vibration syndrome.

BACKGROUND: Standardized laboratory tests are undertaken to assist the diagnosis and staging of hand-arm vibration syndrome (HAVS), but the strength of the relationship between the tests and clinical stages of HAVS is unknown. AIMS: To assess the relationship between the results of thermal aesthesiometry (TA), vibrotactile (VT) thresholds and cold provocation (CP) tests with the modified Stockholm scales for HAVS and to determine whether the relationship is affected by finger skin temperature. METHODS: Consecutive records of workers referred to a Tier 5 HAVS assessment centre from 2006 to 2015 were identified. The diagnosis and staging of cases was undertaken from the clinical information contained in the records. Cases with alternative or mixed diagnoses were excluded and staging performed according to the modified Stockholm scale without knowledge of the results of the standardized laboratory tests. RESULTS: A total of 279 cases of HAVS were analysed. Although there was a significant trend for sensorineural (SN) and vascular scores to increase with clinical stage (P < 0.01), there was no significant difference in scores between 2SN early and 2SN late or between 2SN late and 3SN. There was moderate correlation between the TA and VT scores and the clinical SN stages (r = 0.6). This correlation did not change when subjects were divided into those with a finger skin temperature <30 and >30°C. CP scores distributed bimodally and correlated poorly with clinical staging (r = 0.2). CONCLUSIONS: Standardized SN tests distinguish between the lower Stockholm stages, but not above 2SN early. This has implications for health surveillance and UK policy.

Long-term daily vibration exposure alters current perception threshold (CPT) sensitivity and myelinated axons in a rat-tail model of vibration-induced injury.

Repeated exposure to hand-transmitted vibration through the use of powered hand tools may result in pain and progressive reductions in tactile sensitivity. The goal of the present study was to use an established animal model of vibration-induced injury to characterize changes in sensory nerve function and cellular mechanisms associated with these alterations. Sensory nerve function was assessed weekly using the current perception threshold test and tail-flick analgesia test in male Sprague-Dawley rats exposed to 28 d of tail vibration. After 28 d of exposure, Aß fiber sensitivity was reduced. This reduction in sensitivity was partly attributed to structural disruption of myelin. In addition, the decrease in sensitivity was also associated with a reduction in myelin basic protein and 2',3'- cyclic nucleotide phosphodiasterase (CNPase) staining in tail nerves, and an increase in circulating calcitonin gene-related peptide (CGRP) concentrations. Changes in Aß fiber sensitivity and CGRP concentrations may serve as early markers of vibration-induced injury in peripheral nerves. It is conceivable that these markers may be utilized to monitor sensorineural alterations in workers exposed to vibration to potentially prevent additional injury.

Work disability after diagnosis of hand-arm vibration syndrome.

PURPOSE: Our aim was to study the course of vasospastic and sensorineural symptoms after the clinical diagnosis of hand-arm vibration syndrome (HAVS), and the association of current HAVS symptoms with occupational status, self-evaluation of health, quality of life, and work ability. METHODS: We gathered all HAVS cases diagnosed at the Finnish Institute of Occupational Health in Helsinki and Tampere during 1990-2008. A questionnaire was sent to all these patients (n = 241). Altogether 149 of them (62 %) returned the questionnaire. Cumulative lifelong vibration exposure was evaluated on the basis of the data in the patient files. RESULTS: On average, 8.5 years after the diagnosis of HAVS, approximately one-third of the patients reported improvement in symptoms of vibration-induced white finger (VWF) and the sensorineural symptoms. Young age and shorter exposure time were associated with improvement in VWF symptoms (p = 0.033 and p < 0.001, respectively). Persistent or deteriorated symptoms of both VWF and sensorineural symptoms were associated with lowered work ability, quality of life (EQ-5D), and general health, also after adjusting for age, smoking, and diseases other than HAVS. The patients' own prediction of work ability in 2 years was more negative if the VWF symptoms or sensorineural symptoms had continued after diagnosis of HAVS (p = 0.065 and p = 0.001, respectively). CONCLUSIONS: Our results suggest that in about two-thirds of the patients, the HAVS symptoms may stabilize or deteriorate in the follow-up. Considering the effects on work ability, timely prevention measures should be taken more actively to help patients continue their working careers.

Dependence of vascular damage on higher frequency components in the rat-tail model.

Hand-Arm Vibration Syndrome (HAVS) is caused by hand-transmitted vibration in industrial workers. Current ISO guidelines (ISO 5349) might underestimate vascular injury associated with range of vibration frequencies near resonance. A rat-tail model was used to investigate the effects of higher frequencies >100 Hz on early vascular damage. 13 Male Sprague-Dawley rats (250 ± 15 gm) were used. Rat-tails were vibrated at 125 Hz and 250 Hz (49 m/s(2)) for 1D, 5D and 10D; D=days (4 h/day). Structural damage of the ventral artery was quantified by vacuole count using Toluidine blue staining whereas biochemical changes were assessed by nitrotyrosine (NT) staining. The results were analyzed using one-way repeated measures mixed-model ANOVA at p<0.05 level of significance. The structural damage increased at 125 Hz causing significant number of vacuoles (40.62 ± 9.8) compared to control group (8.36 ± 2.49) and reduced at 250 Hz (12.33 ± 2.98) compared to control group (8.36 ± 2.49). However, the biochemical alterations (NT-signal) increased significantly for 125 Hz (143.35 ± 5.8 gray scale value, GSV) and for 250 Hz (155.8 ± 7.35 GSV) compared to the control group (101.7 ± 4.18 GSV). Our results demonstrate that vascular damage in the form of structural and bio chemical disruption is significant at 125 Hz and 250 Hz. Hence the current ISO guidelines might underestimate vascular damage at frequencies>100 Hz.

Laboratory and field measurements and evaluations of vibration at the handles of riveting hammers.

The use of riveting hammers can expose workers to harmful levels of hand-transmitted vibration (HTV). As a part of efforts to reduce HTV exposures through tool selection, the primary objective of this study was to evaluate the applicability of a standardized laboratory-based riveting hammer assessment protocol for screening riveting hammers. The second objective was to characterize the vibration emissions of reduced vibration riveting hammers and to make approximations of the HTV exposures of workers operating these tools in actual work tasks. Eight pneumatic riveting hammers were selected for the study. They were first assessed in a laboratory using the standardized method for measuring vibration emissions at the tool handle. The tools were then further assessed under actual working conditions during three aircraft sheet metal riveting tasks. Although the average vibration magnitudes of the riveting hammers measured in the laboratory test were considerably different from those measured in the field study, the rank orders of the tools determined via these tests were fairly consistent, especially for the lower vibration tools. This study identified four tools that consistently exhibited lower frequency-weighted and unweighted accelerations in both the laboratory and workplace evaluations. These observations suggest that the standardized riveting hammer test is acceptable for identifying tools that could be expected to exhibit lower vibrations in workplace environments. However, the large differences between the accelerations measured in the laboratory and field suggest that the standardized laboratory-based tool assessment is not suitable for estimating workplace riveting hammer HTV exposures. Based on the frequency-weighted accelerations measured at the tool handles during the three work tasks, the sheet metal mechanics assigned to these tasks at the studied workplace are unlikely to exceed the daily vibration exposure action value (2.5 m s(-2)) using any of the evaluated riveting hammers.

[Hand bones disorders in vibrational disease caused by local vibration should be considered as pathogenetic characteristic of the disease].

Opposite to the authors of the publication, that dystrophic changes in locomotory apparatus of hands and shoulders girdle could not be considered as vibration disease signs, the article authors believe that hand bone changes--tuberosity of distal finger bones, cystic transparency, local osteoporosis--could be pathogenetic signs of vibration disease, along with vascular and neurologic signs. The authors agree that periarthrosis, miofibrosis, if characterized properly through sanitary and hygienic regulations in new List of Occupational diseases, that will be put into practical medicine in the nearest future, could be considered as second occupational disease in the same patient.

[Bone and joint changes caused by exposure to local vibration].

The question to include locomotory disorders into set of symptoms of vibration disease due to local vibration is discussed over years. Studies of clinical symptoms of vibration disease in machinery construction workers demonstrated that bone and joint changes risk depends on intensity of vibration factor and length of exposure to local vibration, as well as on work hardiness. The authors specified X-ray criteria of bone and joint disorders and laboratory markers of bone tissue injury under exposure to local vibration.

Vibration from a riveting hammer causes severe nerve damage in the rat tail model.

INTRODUCTION: Hand-arm vibration syndrome (HAVS) is an occupational neurodegenerative and vasospastic disorder in workers who use powered hand tools. Frequency weighting (ISO 5349) predicts little risk of injury for frequencies >500 HZ. Potentially damaging high frequencies abound in impact tool-generated shock waves. METHODS: A rat tail impact vibration model was developed to deliver shock-wave vibration from a riveting hammer to simulate bucking bar exposure. Rat tails were vibrated continuously for 12 min. Tail flick withdrawal times were determined for noxious heat. Nerve trunks and skin were processed for light and electron microscopy. RESULTS: Immediately after vibration, the tails were hyperalgesic and had disrupted myelinated axons, fragmented nerve endings, and mast-cell degranulation. By 4 days, the tails were hypoalgesic; nerve endings were lost in the skin. CONCLUSIONS: Shock-wave vibration causes severe nerve damage. Frequency weighting seriously underestimates the risk of nerve injury with impact tools.

[State of hepatolienal circulation and liver functions in vibration disease under angioprotector treatment].

The authors demonstrate that angioprotector therapy with Telmisartan in vibration disease patients caused positive effects on hepatolienal circulation, liver microcirculation and clinical functional parameters.

[Should locomotor disorders of upper extremities under exposure to local vibration be considered as a pathogenetic sign of vibration disease?].

To understand role of local vibration in development of locomotory disorders in hands of vibration disease patients, the authors studied relationship between these disorders with major syndromes in vibration disease. Findings are that the main etiologic factor leading to locomotory changes at work with local vibration is a degree of static efforts in this type of work.

[Pulsed low-frequency electrotherapy of vibration disease associated with osteoarthrosis].

The study involving 185 patients with vibration disease and concomitant osteoarthrosis has demonstrated the positive influence of pulsed low-frequency currents in combination with hydrogen sulphide baths on the clinical course of the disease. This combined therapy produced good immediate and late post-treatment results. The data obtained suggest high efficiency of differential application of complex-modulated pulsed and fluctuating currents in patients with vibration disease. It is concluded that amplipulse therapy is the method of choice for the management of this pathology in the absence of apparatuses emitting pulsed currents in the running way regime.