Biomedical subjects

Howard Mason

Publications and source records attributed to Howard Mason.

7 recordsLinked to original sources

PubMed2006

Modification of the Stockholm Vascular Scale.

BACKGROUND: Staging hand-arm vibration syndrome (HAVS) depends upon accurate reporting of the extent and frequency of blanching attacks. Reporting may not be repeatable and not all individuals classifiable using the Stockholm Workshop Scale (SWS). For Department of Trade and Industry (Dti) coal miners' assessments, the SWS was modified to include a blanching score. Further modifications, which involve splitting Stage 2V into 'early' and 'late' have been proposed but the impact of this on classification has not been investigated. AIM: To investigate the impact of modifications in the SWS on HAVS classification. METHODS: Staging of individuals with HAVS according to the SWS using two modified scales. Two different cut-offs for defining 'frequent' blanching attacks (>or=3 or >or=7 attacks/week, respectively) were used. RESULTS: One hundred and sixty-five individuals were staged. Using the SWS, 58 and 31% of the population were unclassifiable using the two cut-offs, respectively. The modification splitting Stage 2V reduced the proportions that were unclassifiable to 2 and 9%, respectively, and increased those classified as Stage 2V. The cut-off for frequent attacks used (3 or 7) affected the proportion of individuals falling into the subdivisions of Stage 2 with 17 and 42% being classified as 2Vearly and 45 and 20% as 2Vlate, respectively. CONCLUSIONS: Subdividing Stage 2V enables more individuals to be classified, but the proportion falling into each category is susceptible to the cut-off used for defining frequent attacks. Caution may need to be applied if this categorization is used to make decisions regarding fitness to work.

Arm↗

PubMed2006

Speciation of arsenic compounds in urine from occupationally unexposed and exposed persons in the U.K. using a routine LC-ICP-MS method.

This paper describes a routine, robust, and reproducible liquid chromatography-inductively coupled plasma-mass spectrometry (LC-ICP-MS) speciation method for five arsenic compounds [arsenobetaine (AB), arsenite, arsenate, monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA)] in urine. Concentrations of these arsenic species in urine samples are reported in two sets of non-occupationally exposed controls with one set having consumed fish within 24 h (n = 31) and the other not having consumed fish for 48 h (n = 34). Arsenic species in urine samples from workers in both the timber treatment industry (n = 49) and semiconductor industry (n = 46) are also reported. The arsenic content in all of the samples was also determined using hydride-generation coupled with ICP-MS. The results show that urine samples from people not occupationally exposed to arsenic contain low levels of DMA, MMA, and AB and that only urine from smokers contained any inorganic arsenic. Consumption of seafood was seen to significantly increase the levels of AB and DMA in the unexposed persons. Urine samples from the semiconductor workers exhibited significantly higher levels of arsenite, arsenate, and DMA than the unexposed samples. The urine samples from timber treatment workers exhibited significantly higher levels of four arsenic species (not AB) than those observed in both the control groups and the semi-conductor workers.

Anion Exchange Resins↗

PubMed2006

Cold-provocation testing for the vascular component of hand-arm vibration syndrome in health surveillance.

The aim was to investigate whether the use of infra-red thermography (I-R) and measurement of temperature gradients along the finger could improve the diagnostic accuracy of cold-provocation testing (15 degrees C for 5 min) in vascular hand-arm vibration syndrome (HAVS). Twenty-one controls and 33 individuals with stages 2/3V HAVS were studied. The standard measurement of time to rewarm by 4 degrees C (T4 degrees C) and temperature gradients between the finger tip, base and middle (measured using I-R) were calculated. Receiver Operating Characteristics (ROC) analysis to distinguish between the two groups revealed that for T4 degrees C the area under the ROC curve was not statistically significantly different from 0.5 (0.64 95% confidence interval 0.49-0.76). The difference between the tip and middle portion of the finger during the sixth minute of recovery was the most promising gradient with an area of 0.76 (95% confidence interval 0.62-0.87), and sensitivity and specificity of 57.6% and 85.7% respectively. However, this was not significantly different from that for the time to rewarm by 4 degrees C. In conclusion, the cold-provocation test used in this study does not appear to discriminate between individuals with stage 2/3V HAVS and controls and this is not improved by the measurement of temperature gradients along the fingers using I-R.

Adult↗

PubMed2005

Disability in the upper extremity and quality of life in hand-arm vibration syndrome.

PURPOSE: To investigate whether hand-arm vibration syndrome (HAVS) leads to disability in the upper extremity or deficit in quality of life (QoL) using validated questionnaire tools, and to establish whether these effects are related to the Stockholm Workshop Staging (SWS). METHOD: This was a postal cross-sectional questionnaire study with a 50% response rate. Four hundred and forty-four males, who had been diagnosed and staged according to the SWS were sent the Disability in the Arm, Shoulder and Hand (DASH) and the SF-36v2 QoL questionnaires. RESULTS: HAVS cases had significantly greater DASH disability scores and reduced QoL physical and mental component scores compared to published normal values. Those HAVS cases with a presumptive diagnosis of Carpal Tunnel Syndrome(CTS) had even higher disability scores. There was a clear, linear relationship between both the DASH disability score and the physical component of the QoL and sensorineural SWS, but not with the vascular SWS. CONCLUSIONS: HAVS has a significant effect on an individual's perceived ability to perform everyday tasks involving the upper extremity, and their quality of life. Physical capability may be further compromised in those individuals who have a presumptive diagnosis of CTS. These findings may have important implications regarding management of the affected worker.

Activities of Daily Living↗

PubMed2005

Window renovation and exposure to lead--an observational study.

BACKGROUND: Renovation of windows in old houses has recently established itself as an industry. A recognizable occupational lead exposure exists, which has not been studied previously. AIM: To compare lead exposure amongst window renovators with other groups of lead-exposed workers. METHODS: Using blood lead results measured at the Health and Safety Laboratory (HSL), Sheffield, comparisons were made between three cohorts: window renovation workers, all male workers monitored by HSL during the period 1999-2001 and 63 male subjects involved in chemical paint-stripping of wood. RESULTS: Both the window renovation and the wood-stripping cohorts show significantly higher blood lead distributions than the 'all workers' cohort (P < 0.001). A similar pattern was also found for comparison of the prevalence of subjects above the UK suspension level of 60 microg/dl (2.89 microM) (window renovation, P < 0.001; wood-stripping, P < 0.0001). Blood lead results at or above the suspension level in wood-strippers were significantly higher compared to window renovators (P = 0.034). CONCLUSION: Window renovation is shown to present a potential for significant lead exposure, and suspension from work under The Control of Lead at Work Regulations 2002. Two groups of risk factors predominate: the well-documented potential for release of lead from old paint, and the peripatetic nature of the work.

Chemical Industry↗

PubMed2005

Urinary corticosterone measures: effects of strain and social rank in BKW and CD-1 mice.

We used urinary assays as a non-invasive method to examine corticosterone levels in two outbred strains of male laboratory mice (BKW and CD-1). Measures were taken before and after 2 weeks of pair housing, to examine the effects of social stress. We found that CD-1 mice had significantly higher corticosterone levels compared to BKW mice both before and after pairing. Behavioural measures provided evidence that, when paired, both strains of mice polarised into dominants and subordinates, with a higher overall incidence of aggressive acts in the BKW mice. Some pairings had to be separated to prevent injuries so the pairing procedure introduced a selection for non-aggressive socially tolerant mice. Social status was nevertheless found to be associated with pre-existing differences in urinary corticosterone in the CD-1 strain: mice that later became dominant had overall lower levels of urinary corticosterone compared to subordinates. In conclusion, urinary corticosterone levels indicated clear differences in physiology, likely to be related to the adrenal stress response, dependent on both strain and social status. Thus, this non-invasive measure could help to predict the welfare outcomes of social housing and how these may depend on dominance status, rather than overall levels of aggression, in different strains of mice.

Aggression↗

PubMed2005

A screening questionnaire for HAVS?

AIM: To define the diagnostic power of simple questions most applicable for a hand-arm vibration syndrome (HAVS) assessment screening questionnaire. METHOD: Using a binary logistic regression we analysed 365 physician led HAVS health surveillance assessments to identify which questions could form the basis of a screening questionnaire. RESULTS: Four sensorineural related questions regarding tingling and numbness in response to the cold and after using vibrating tools, and two vascular-related questions focusing on the patient's fingers going white on exposure to cold and numbness during an attack of whiteness were identified. CONCLUSIONS: Questions of high sensitivity for screening subjects for the vascular and neurosensory components of HAVS were identified, which can be used to identify those requiring further clinical investigation and functional testing.

Adult↗