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Biomedical subjects

M Cherniack

Publications and source records attributed to M Cherniack.

16 recordsLinked to original sources
PubMed2006

Nerve conduction and sensorineural function in dental hygienists using high frequency ultrasound handpieces.

BACKGROUND: Oscillatory vibration from industrial power tools poses a well-recognized risk of peripheral nerve injury. There have been reports of elevated vibrotactile perception thresholds (VPT) among dentists, dental technicians, and dental hygienists, using rotary devices and ultrasonics. Elevated VPTs are an indicator of small fiber nerve or mechanoreceptor injury, but the high frequencies associated with dental instruments are presumed by the ISO to exceed physiological response upper thresholds. This study examines nerve conduction and sensorineural deficits in dental hygienists. METHODS: A cross-sectional study of 94 experienced dental hygienists was conducted to assess peripheral nerve function and clinical signs and symptoms. Specialized testing included measurement of VPTs for three different categories of mechanoreceptors, sensory nerve conduction tests with fractionated digit and palmar segments, and measurement of calibrated pinch force with force sensitive resistors (FSRs) during a simulated procedure. RESULTS: Chronic hand paresthesias were described by 44.7% of experienced dental hygienists. Sensory nerve conduction velocity (SNCV) across the wrist-palm segment of the median nerve. VPTs were particularly elevated at the FAII mechanoreceptor among experienced dental hygienists. Compared to participants without carpal tunnel syndrome (CTS), as defined by study criteria, 14 experienced hygienists with diagnosed CTS had almost twice the average weekly use of vibratory instruments -8.3 hr versus 4.5 hr, and had SNCV deficits along the digit -47.11 m/sec (+8.70) versus 42.57 m/sec (+8.25), and across the wrist -44.04 m/sec (+7.15) versus 41.36 m/sec (+9.27). There was a distinct subset of dental hygienists (27%) with a combination of low calibrated pinch force in simulations, subjective loss of strength and elevated VPTs, especially in the FAII mechanoreceptor population -110.82 db (+8.57) versus 104.84 db (+6.80) in the rest of the cohort. This subset also had a higher prevalence of paresthesias (67% vs. 39%) and greater cumulative vibration exposure (OR = 1.206 [CI 1.005-1.448]), than other hygienists. CONCLUSIONS: The high levels of paresthesias observed among dental hygienists appear to be attributable to several pathophysiological mechanisms, including, sensory nerve demyelination at the carpal tunnel and intrinsic to the digits, and dysfunction of fingertip mechanoreceptors. A distinct sub-population appears to exhibit a high level of accumulated abnormality.

Adult↗
PubMed2005

Digital vibration threshold testing and ergonomic stressors in automobile manufacturing workers: a cross-sectional assessment.

Upper extremity musculoskeletal disorders (UEMSDs) comprise a large proportion of work-related illnesses in the USA. Physical risk factors including manual force and segmental vibration have been associated with UEMSDs. Reduced sensitivity to vibration in the fingertips (a function of nerve integrity) has been found in those exposed to segmental vibration, to hand force, and in office workers. The objective of this study was to determine whether an association exists between digital vibration thresholds (VTs) and exposure to ergonomic stressors in automobile manufacturing. Interviews and physical examinations were conducted in a cross-sectional survey of workers (n = 1174). In multivariable robust regression modelling, associations with workers' estimates of ergonomic stressors stratified on tool use were determined. VTs were separately associated with hand force, vibration as felt through the floor (whole body vibration), and with an index of multiple exposures in both tool users and non-tool users. Additional associations with contact stress and awkward upper extremity postures were found in tool users. Segmental vibration was not associated with VTs. Further epidemiologic and laboratory studies are needed to confirm the associations found. The association with self-reported whole body vibration exposure suggests a possible sympathetic nervous system effect, which remains to be explored.

Adult↗
PubMed2004

Segmental nerve conduction velocity in vibration-exposed shipyard workers.

OBJECTIVES: Segmental sensory nerve conduction velocity (SNCV) was measured from the wrists to the hands and digits of a population of vibration-exposed shipyard workers. This study was designed to investigate whether SNCV was selectively slowed in the fingers and whether a laboratory approach could be adapted for robust field use. METHODS: Wrist-palm, palm-proximal digit, and digital segments were determined from stimulation at the wrist with recording electrodes placed distally and adjusted to individual anatomy. The cohort was selected on the basis of current use of vibratory tools. RESULTS: Wrist-palm and digital segments were slower than palm-proximal digit segments for dominant and non-dominant hands and for both ulnar and median nerves. In the dominant-hand median nerve of participants with current exposure, the SNCV was 41.4 m/s (SD 8.0) for the wrist-palm segment, 50.8 (SD 9.5) for the palm segment, and 42.1 m/s (SD 9.3) for the digital segment. Temperature had an important effect on nerve conduction velocity but not equally across segments. Other explanatory variables had modest effect on SNCV. CONCLUSIONS: Reduced SNCV in the digits may be a consequence of industrial exposure to vibration. Each sensory nerve segment appeared to have a different characteristic velocity and different pattern of association with skin temperature. There are differences between median and ulnar nerve segments, with potentially important consequences when standard distances are used to assess wrist-digit velocity.

Carpal Tunnel Syndrome↗
PubMed2003

Skin temperature recovery from cold provocation in workers exposed to vibration: a longitudinal study.

BACKGROUND: Vibration white finger (VWF) is characterised by arterial hyperresponsiveness and vasoconstriction following cold provocation. Several years after of removal from exposure, most subjects show improved finger systolic blood pressure (FSBP) under conditions of cold challenge, but continue to report cold hands and finger blanching. AIMS: To assess the underlying reasons for the persistence of cold symptoms. METHODS: A total of 204 former users of pneumatic tools with cold related hand symptoms were evaluated and then re-evaluated a year later. Symptoms were evaluated using the Stockholm Workshop Scale. Finger systolic blood pressure per cent (FSBP%) was assessed by comparing digital blood pressure in a cold provoked and normalised state. Fingertip skin temperature was measured during cooling and occlusion and during rewarming and recovery. RESULTS: There were dramatic improvements in FSBP% (14.3 mm Hg %), modest improvement in recovered skin temperature (0.86 degrees C), and no change in symptom stage. When the most symptomatic subjects (n = 75) were compared with the less symptomatic subjects (n = 129), there were similar inter-test improvements in FSBP%. Skin temperature recovery improved in the less symptomatic (+1.49 degrees C), but did not change in the most symptomatic group (-0.12 degrees C). However, the more symptomatic group had higher temperatures at the initial test, thus qualifying the result. CONCLUSIONS: Skin temperature recovery after cold challenge in subjects with VWF remains reduced in the symptomatic subjects several years after exposure removal. This is evident even when blood pressure has increased in the setting of cold provocation. Results suggest that in VWF, the dermal circulation remains impaired, even after the restoration of arterial blood pressure in the digits.

Adult↗
PubMed2001

The creation of ergonomic data sheets for hazard communication of work-related musculoskeletal disorders.

Information on human health hazards caused by chemical exposure has traditionally been supplied through Material Safety Data Sheets (MSDS). This report describes development of an analogous Ergonomic Data Sheet (EDS) to address hazards of work-related musculo-skeletal disorders (WRMSD) from use of hand tools. The EDS includes sections on risk factors for WRMSD, design aspects of the tool that decrease risks, precautionary measures, and objective testing of the tool compared to other comparable tools. The EDS can be used within an Ergonomic Communication Program similar to a Hazard Communication Program.

Communication↗
PubMed2000

Evaluation and management of chronic work-related musculoskeletal disorders of the distal upper extremity.

This clinical review will describe the epidemiology, clinical presentation, and management of the following work-related musculoskeletal disorders (WMSDs) of the distal upper extremity: deQuervain's disease, extensor and flexor forearm tendinitis/tendinosis, lateral and medial epicondylitis, cubital tunnel syndrome, and hand-arm vibration syndrome (HAVS). These conditions were selected for review either because they were among the most common WMSDs among patients attending the New York State Occupational Health Clinics (NYSOHC) network, or because there is strong evidence for work-relatedness in the clinical literature. Work-related carpal tunnel syndrome is discussed in an accompanying paper. In an attempt to provide evidence-based treatment recommendations, literature searches on the treatment of each condition were conducted via Medline for the years 1985-1999. There was a dearth of studies evaluating the efficacy of specific clinical treatments and ergonomic interventions for WMSDs. Therefore, many of the treatment recommendations presented here are based on a consensus of experienced public health-oriented occupational medicine physicians from the NYSOHC network after review of the pertinent literature. A summary table of the clinical features of the disorders is presented as a reference resource.

Arm↗
PubMed2000

Vibration exposure, smoking, and vascular dysfunction.

OBJECTIVES: Vibration white finger (VWF), also known as "occupational Raynaud's phenomenon", is marked by arterial hyperresponsiveness and vasoconstriction during cold stimulation. The impact of tobacco use, and by extension stopping smoking, on the long term course of the disease has been inconclusively characterised. The objectives of this study included assessment of the impact of tobacco use on symptoms and on objective tests in shipyard workers exposed to vibration, and in gauging the natural history of the disorder after stopping exposure and changing smoking patterns. METHODS: In a cross sectional investigation, 601 current and former users of pneumatic tools were evaluated subjectively for cold related vascular symptoms, and tested by cold challenge plethysmography. There was follow up and subsequent testing of 199 members of the severely effected subgroup of smokers and non-smokers, many of whom had stopped smoking in the interval between tests. Effects of smoking and stopping smoking on symptoms and plethsymographic results were assessed. RESULTS: Symptoms and measured abnormal vascular responses related to cold were more severe in smokers than in non-smokers. Follow up of 199 severely effected members of the cohort, all removed from exposure for 2 years, indicated that smokers were almost twice as likely to have more severe vasospasm (test finger/control finger systolic blood pressure% (FSBP%) <30) than were non-smokers (-32.2% v 17.4%). 53 Subjects who stopped smoking during the interval between tests improved, and were indistinguishable from non-smokers similarly exposed to vibration. Additional physiological benefits of stopping smoking were still apparent at further follow up examination, 1 year later. Improvements evident on plethysmography were not accompanied by improvements in symptoms, which were unaffected by smoking. CONCLUSIONS: Smoking seems to delay physiological improvement in response to cold challenge in workers with VWF, after the end of exposure to vibration. Symptoms were less likely to improve over time than digital blood pressure, and were less affected by smoking.

Adult↗
PubMed2000

Use of health information systems in the Russian federation in the assessment of environmental health effects.

The Russian Federation has made an intensive effort to compile and use information on the environment and human health. In 1996-1997, we evaluated the information that was collected and analyzed on the local (raion), regional (oblast), and federal levels with reference to its usefulness in the assessment of environmental health effects. The Russian Federation maintains standardized nationwide institutions that routinely collect health data in polyclinics and hospitals and then report to the national offices. The allocations of the workforce and the broad range of surveyed health outcomes are extensive, but a lack of systematic control of information quality limits the ability to take full advantage of these efforts. On the other hand, the hierarchical system of data collection has advantages over more decentralized or commercial health systems. A major weakness in the current reporting is the aggregation and transformation of data. Although this may not disturb the generation of health statistics, it seriously limits the use of regional and federal level data in the assessment of health effects of environmental exposures. In spite of limitations, some revised approaches to the analysis of existing data may be both feasible and fruitful. Combining information from routine data and newly collected data is likely to be the most effective way to assess the relationship between environmental exposures and diseases. Although there is a strong and justifiable desire to rapidly translate information of environmental health effects into policy alternatives, at present, it seems more useful to emphasize data quality, completeness, and plans for the use of data.

Data Collection↗
PubMed1998

Clinical evaluation of hand-arm-vibration syndrome in shipyard workers: sensitivity and specificity as compared to Stockholm classification and vibrometry testing.

The hand-arm-vibration syndrome (HAVS) is a complex entity composed of circulatory, sensory, and motor disturbances, as well as associated musculoskeletal components. This study was performed to find a diagnostic testing modality with sufficient sensitivity, specificity, and predictive value to be utilized as a screening test for this disorder in a working population. A full range of testing modalities was utilized in the shipyard medical department. In addition, a clinical diagnosis of vascular and sensorineural disease was established in the workers by a combination of plethysmography, vibrometry, two point discrimination, and monofilament testing in an independent occupational medicine clinic. No one test modality met the requirements for such a definitive diagnostic test. Rather, a range of modalities was required to reach any acceptable level of predictive value, with sufficient degrees of specificity and sensitivity.

Adult↗
PubMed1993

Statistical design and monitoring of the Carotene and Retinol Efficacy Trial (CARET).

CARET is a chemoprevention trial of beta-carotene and vitamin A with lung cancer as the primary outcome. Participants at high risk for lung cancer are drawn from two populations: asbestos-exposed workers and heavy smokers. The intervention is a daily combination of 30 mg beta-carotene and 25,000 IU vitamin A as retinyl palmitate. Nearly 18,000 participants will be followed for a mean 6 years, yielding over 100,000 person-years of follow-up. We project that this sample size will have 80% power to detect a 23% decrease in the incidence of lung cancer cases. The purpose of this paper is to present the values of the key sample size parameters of CARET; our schemes for monitoring CARET for sample size adequacy, incidence of side effects, and efficacy of the study vitamins; an overview of the data collected; and plans for the primary, secondary, and ancillary analyses to be performed at the end of the trial. These approaches to the design, monitoring, and analysis of CARET are applicable for many other prevention trials.

Aged↗
PubMed1991

CARET, the beta-carotene and retinol efficacy trial to prevent lung cancer in asbestos-exposed workers and in smokers.

CARET is a two-armed, double-blind, randomized chemo-prevention trial to test the hypothesis that oral administration of beta-carotene 30 mg/day plus retinyl palmitate 25,000 IU/day will decrease the incidence of lung cancer in high-risk populations: heavy smokers and asbestos-exposed workers who have smoked. The agents combine anti-oxidant and nuclear tumor suppressor mechanisms. Fastidious monitoring for possible side effects is facilitated by inclusion of a Vanguard population. As of 31 December 1990, 6,105 participants of the 18,000 needed have been randomized in the trial. Efficacy results are expected in 1999.

Aged↗
PubMedDate not supplied

Clinical and psychological correlates of lumbar motion abnormalities in low back disorders.

BACKGROUND CONTEXT: Low back pain (LBP) and low back disorders (LBDs) identify a complex constellation of conditions that frustrate both diagnosis and therapy. Dynamic quantitative assessment and questionnaire instruments directed toward psychosocial and situational variables provide potentially powerful tools for determining functional pathology and potentially outcome. PURPOSE: Our goal was to independently assess clinical correlates of a trunk motion measurement device, the lumbar motion monitor (LMM). The reliability of the LMM as a clinical test was assessed by comparison with an independent medical examination and biobehavioral questionnaires. STUDY DESIGN/SETTING: There were three study components. A multispecialty physician panel that administered a structured physical examination contributed to a clinical correlation case series study. Standardized outcomes and risk identification questionnaires were administered to the case population. Finally, the LMM was administered in a customary fashion to the same population. PATIENT SAMPLE: Nineteen subjects were recruited on the basis of criteria that included symptoms of chronic recurrent low back pain. This was an employed and active, although impaired, population. Eighteen of the subjects were currently employed with limited lost work time, but chronic and recurrent pain was a common feature. OUTCOME MEASURES: Questionnaire outcome measures were both characterologic and situation based. In addition to providing diagnoses, the physician panel was also asked to offer certain qualitative assessments, such as rehabilitative potential and functional level pertinent to activities of daily living. The impact of LMM measures on physician decision making was also assessed. Trunk angular measurements were used to assess function of patients with chronic low back disorders. METHODS: Kinematic performance on the LMM was expressed as three probability scores. These were the likelihood of abnormality, the "sincerity of effort" (exacerbation or aggravation of impairment), and the likelihood of structural anatomic disease. These variables were examined against established self-report measures of pain and disability. RESULTS: The LMM and physician panels were in agreement on the presence or absence of abnormality. LMM findings tended to be more consistent with clinical history than the clinical examination. The LMM results were also generally consistent with the self-reported measures of pain and disability: a high likelihood of structural disease was associated with depression, somatization, poor health perception and diminished vitality. CONCLUSIONS: The LMM appears to be a useful assessment tool for gauging the presence of LBP and LBD. It was accurate in detecting abnormality when abnormality was determined by clinical history and physician diagnosis. The LMM's differentiation of mechanical low back disease (nonanatomically specific disorders) from structurally specific low back disease was not consistent with a parallel clinical differentiation. Larger trials in a prospective format and studies on a chronically disabled population seem warranted. In an impaired but less disabled population, elevated pain and somatization did not appear to weaken the effort during testing.

Adult↗
PubMedDate not supplied

Ambiguities in office-related injury: the poverty of present approaches.

This is a straightforward entry into the fray over the association of upper extremity disorders with the modern workplace. The authors point out that successful intervention and prevention efforts are underway around the world, despite the continuing debate on theory.

Arm Injuries↗