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Biomedical subjects

N R Williams

Publications and source records attributed to N R Williams.

At least 19 recordsLinked to original sources
PubMed2003

Investigating and analysing workplace clusters of diseases: a Health & Safety Executive perspective.

BACKGROUND: Clusters of disease arising in workplaces cause concern among the management of the company, the workers affected and their families and friends. Chance is the most likely explanation for their occurrence, although a number of real workplace hazards have been identified through their observation and investigation. Employers have a duty to investigate such occurrences in order to assess whether some unknown or unidentified hazard is at work and to take the appropriate action. Several papers have been published over the last 15 years or so that set out a method for investigating workplace clusters of disease. Aims This paper presents the steps in the approach taken by the Health & Safety Executive in Great Britain. METHOD: An initial step identifies the relevant stakeholders at the outset, in order to maintain a realistic expectation of what the investigation can hope to achieve and to open a dialogue. The main steps in the assessment are: (1) identifying cases; (2) determining the other parameters of the investigation; (3) statistically assessing the cluster; (4) examining potential exposures and assessing their biological plausibility; and (5) determining the overall significance of the cluster. The approach is illustrated throughout by examples.

Cluster Analysis↗
PubMed2003

Occupational groups at risk of voice disorders: a review of the literature.

BACKGROUND: Occupational voice health is becoming more important as more people rely on their voices for their work. A number of studies have identified certain occupational groups at increased risk of developing occupational voice disorders, namely teachers, singers and aerobics instructors. Aim The paper aims to review the literature on occupational groups at risk of voice disorders and identify areas for future research. METHOD: A literature review of key databases using key words such as 'occupational', 'voice health', 'voice loss', 'dysphonia' and 'work related' was undertaken. RESULTS: The review identified case reports, studies of attendees at hospital voice clinics and a few cross-sectional studies of occupational groups in the workplace. There were no longitudinal studies found or intervention studies looking at reduction of risk. CONCLUSION: Further research on occupational voice disorders needs to be based in the workplace, and to look at the risk factors for the development of voice problems and for the efficacy of controls.

Exercise↗
PubMed2003

Voice recognition products-an occupational risk for users with ULDs?

BACKGROUND: Voice recognition systems (VRS) allow speech to be converted both directly into text-which appears on the screen of a computer-and to direct equipment to perform specific functions. Suggested applications are many and varied, including increasing efficiency in the reporting of radiographs, allowing directed surgery and enabling individuals with upper limb disorders (ULDs) who cannot use other input devices, such as keyboards and mice, to carry out word processing and other activities. Aim This paper describes four cases of vocal dysfunction related to the use of such software, which have been identified from the database of the Voice and Speech Laboratory of the Massachusetts Eye and Ear infirmary (MEEI). METHOD: The database was searched using key words 'voice recognition' and four cases were identified from a total of 4800. RESULTS: In all cases, the VRS was supplied to assist individuals with ULDs who could not use conventional input devices. Case reports illustrate time of onset and symptoms experienced. CONCLUSION: The cases illustrate the need for risk assessment and consideration of the ergonomic aspects of voice use prior to such adaptations being used, particularly in those who already experience work-related ULDs.

Adult↗
PubMed2003

Monitor.

Explore the source record for details and available documents.

Adult↗
PubMed2003

A survey of the role of the UK physicist in nuclear medicine: a report of a joint working group of the British Institute of Radiology, British Nuclear Medicine Society, and the Institute of Physics and Engineering in Medicine.

Guidelines for the provision of physics support to nuclear medicine were published in 1999 by a joint working group of the British Institute of Radiology, the British Nuclear Medicine Society, and the Institute of Physics and Engineering in Medicine. Following publication of the guidelines, a survey was conducted by the working group to gather data on the actual level of physicist support in UK hospitals of different types and on the activities undertaken by physicists. The data were collected in the 12 months following the publication of guidelines and cover different hospital models and seven UK regions. The results provide evidence that many of the smaller units - small teaching hospitals and, particularly, small district general hospitals - have insufficient physics support. Although, on average, there is good agreement between the guidelines and the survey data for medium and large district general hospitals, there is wide variation in the level of physics provision between hospitals delivering apparently similar services. This emphasizes the need for national guidelines, against which institutions may be bench-marked and which may be used as a recommendation for the staffing levels necessary to ensure services are delivered safely and standards are not compromised. The complexity and variety of workload is an important factor in determining the level of physics support. As services develop, it is vital that this aspect is recognized to ensure that appropriate resources are available for the required physics input, even if any new service represents only a modest clinical throughput in terms of patient numbers.

Data Collection↗
PubMed2002

Occupational voice disorders due to workplace exposure to irritants--a review of the literature.

The medical literature contains relatively few examples of reports of voice disorders that could be attributed to chemical exposure at work. General medical conditions such as gastro-oesophageal reflux and the use of medication such as inhaled steroids are well-recognized causes of laryngitis, but the occupational causes are less well documented. This paper describes the results of a literature review looking at the reporting of cases of occupationally acquired voice disorders due to exposure to irritants in the workplace.

Agricultural Workers' Diseases↗
PubMed2002

Acute ingestion of red wine by men activates platelets but does not influence endothelial markers: no effect of white wine.

Long-term moderate alcohol use is associated with a better cardiovascular risk profile than total abstinence, although the short-term effect of a bolus of alcohol is unclear. The hypothesis tested in this study was that an acute bolus of alcohol would adversely affect the endothelium and platelets. Blood was taken before and 4 h after the ingestion of red or white wine by nine volunteers per group, and by 11 control water-only drinkers at the same time points. Plasma was obtained and markers of platelet activity (beta-thromboglobulin and soluble P selectin) and endothelial cell function (von Willebrand factor and soluble thrombomodulin) measured by enzyme-linked immunosorbent assay. The only marker to change significantly was beta-thromboglobulin, which increased from a median of 10 ng/ml (interquartile range, 8.5-15) before drinking red wine to 16 ng/ml (interquartile range, 14-20) 4 h later (P = 0.0067). We conclude that an acute bolus of red wine, but not white wine, activates platelets but has no substantial effect on the endothelium.

Adult↗
PubMed2001

Leucocyte copper, a marker of copper body status is low in coronary artery disease.

To elucidate the relationship between leucocyte copper as a reliable, sensitive index of copper body status and extent of atherosclerosis in patients with Coronary Artery Disease (CAD) the present case-control study was carried out. 80 subjects were studied (23 females and 57 males), aged between 30-70, due to have a angiography. Individual angiograms were scored by combining the individual scores in all the major coronary arteries into one score of a scale 1.00 for patency to 0.00 for severe CAD. Serum and leucocyte copper and zinc were determined by GFAAS. No significant difference between patients with advanced CAD and relatively normal arteries were observed in the lipid profile and levels of plasma copper. Leucocyte copper had a significant link with the severity of atherosclerosis which was independent of sex. There was a linear relationship between the degree of decreasing leucocyte copper concentration and angiogram score. These findings give support to the hypothesis that marginal copper status, assessed by decreased leucocyte copper level, is associated with developing CAD.

Adult↗
PubMed2001

Death due to inhalation of industrial acetylene.

CASE REPORT: Acetylene is a commonly found industrial agent that, when mixed with oxygen, is used for welding. This report outlines circumstances surrounding the death of a 40-year-old male with presumptive evidence of abuse of the substance and subsequent death. The article covers the uses of acetylene, the toxic effects attributed to the gas, and the circumstances of the incident.

Acetylene↗
PubMed2001

Biological monitoring and exposure to mercury.

Occupational health professionals' interest in controlling mercury (Hg) exposure, and the use of biological monitoring in this context, has been ongoing for a number of years. Evidence from urinary Hg results in a number of UK firms who have undertaken some form of biological monitoring or occupational health surveillance suggest that exposure has decreased over the last 10-15 years. This decrease precedes the establishment in the UK of an advisory biological monitoring guidance value (HGV) for urinary Hg and the production of updated medical guidance from the Health & Safety Executive on Hg exposure (MS12 1996). This latter document recommends a urinary sampling interval for urinary Hg of between 1 and 3 months, which is consistent with the reported toxicokinetics of Hg excretion, but we highlight that urinary Hg represents integrated exposure over many previous months. Mercury is a recognized nephrotoxin and MS12 1996 mentions the use of regular dipstick protein estimations. We review our experience of investigating proteinuria and enzymuria in a large-scale cross-sectional occupational study. The incidence of Hg-induced renal disease is probably very rare at current exposure levels. Therefore acceptance of a high false-positive rate of proteinuria not related to Hg exposure needs to be considered in any urinary protein testing regime of Hg workers. The establishment of an HGV for urinary Hg has raised questions about the uncertainty associated with a urinary Hg result, including factors such as diurnal variation, whether urine correction by creatinine or specific gravity is preferable and the possibility of non-occupational sources of Hg contributing significantly towards breaching the HGV. Correction of urinary Hg results by creatinine or specific gravity and the use of a fixed sampling time, such as the beginning or end of the day, substantially reduce the uncertainty in a urinary Hg measurement. But even with good laboratory precision, an individual with a true urinary Hg excretion of 20 nmol/mmol creatinine could supply urine samples of between 14 and 26 nmol/mmol creatinine. The influence of dietary sources in the UK contributing to urinary Hg values approaching or exceeding the HGV is unlikely. The use of tribal or ethnic cosmetics and remedies needs to be considered if a urinary Hg result looks inappropriately high, as some such preparations have been found to contain Hg and can be absorbed through the skin. The ability of excessive chewers or teeth grinders who have a large number of dental amalgam fillings to breach the urinary HGV in the absence of substantial occupational Hg exposure has been reported in a few Scandanavian studies. We report here a likely case of this phenomenon. Since the establishment of the HGV, our biological monitoring Hg data from a number of industry sectors using inorganic or metallic Hg have suggested that a minority of samples (13%) are still greater than the HGV.

Cross-Sectional Studies↗
PubMed2000

Paraoxonase activity in two healthy populations with differing rates of coronary heart disease.

BACKGROUND: The rate of coronary heart disease is over three-fold greater in Belfast than in Toulouse and the excess risk cannot be totally explained by 'classical' risk factors such as total cholesterol, LDL-cholesterol, smoking, etc. DESIGN: The effect of the human serum paraoxonase (PON1) 192-genetic polymorphism on plasma lipid and lipoprotein concentrations and on PON1 activity and concentration was investigated in 186 randomly selected healthy subjects from Toulouse and 165 from Belfast. RESULTS: The frequency of the R allele of PON1, which has been related to the risk of coronary heart disease, was significantly higher in Belfast (0.33) than in Toulouse (0.24; chi2 = 7.229, P = 0.0072). Subjects from Belfast also had significantly higher serum cholesterol, triglycerides, LDL-cholesterol, and apolipoprotein B, and significantly lower HDL-cholesterol and apolipoprotein A1, but these lipoprotein parameters were independent of the PON1 192-polymorphisms. PON1 activity towards paraoxon was significantly higher in the Belfast population than in Toulouse (median values: 179.7 vs. 129.4 nmol min-1 mL-1 serum, respectively; P < 0.05), which is consistent with our finding of a greater prevalence of the R allele. The median serum concentration of PON1 was 56.3 microgram mL-1 in Belfast, which was significantly lower (P < 0.005) than the level of 71 microgram mL-1 in Toulouse. CONCLUSIONS: Our results thus provide further support for the hypothesis that populations at increased CHD risk have diminished serum PON1 concentration and an increased prevalence of the R allele of PON1. They are also consistent with reports that the ability of PON1 to hydrolyse paraoxon is inversely related to its capacity to hydrolyse lipid-peroxides, and thus to its antiatherogenic action.

Aged↗
PubMed2000

Estimation of ascitic fluid volume using 99Tcm labelled macroaggregated albumin.

We have assessed the usefulness of a radionuclide dilution method for estimation of ascitic fluid volume. 99Tc(m) macroaggregated albumin (10 MBq) was injected into the peritoneal fluid. Multiple samples were taken using a trocath peritoneal dialysis catheter over a 4-h period. Blood samples were taken at the same time and a 4-h urine collection was made during the study. At 4 h a controlled drainage of ascitic fluid, followed by suction drainage, was used and a total drained volume measured. For comparison, peritoneal volumes were measured from the radioactivity of peritoneal fluid activity samples using dilution techniques. The estimated peritoneal fluid volume using the radionuclide method was consistently higher than the drained volume. This was attributed to either a lack of uniform distribution of the activity in the peritoneal cavity by 4 h or early breakdown and absorption of activity from the peritoneal cavity. In two patients it was not possible to measure a volume due to poor distribution of the radionuclide in the peritoneal fluid. We found that in our group of patients the radionuclide dilution is of little value in estimating the peritoneal fluid volume.

Adult↗
PubMed2000

Insulin response and changes in composition of non-esterified fatty acids in blood plasma of middle-aged men following isoenergetic fatty and carbohydrate breakfasts.

It was previously shown that a high plasma concentration of non-esterified fatty acids (NEFA) persisted after a fatty breakfast, but not after an isoenergetic carbohydrate breakfast, adversely affecting glucose tolerance. The higher concentration after the fatty breakfast may in part have been a result of different mobilization rates of fatty acids. This factor can be investigated as NEFA mobilized from tissues are monounsaturated to a greater extent than those deposited from a typical meal. Twenty-four middle-aged healthy Caucasian men were given oral glucose tolerance tests (OGTT), and for 28 d isoenergetic breakfasts of similar fat composition but of low (L) or moderate (M) fat content. The composition of NEFA in fasting and postprandial plasma was determined on days 1 and 29. No significant treatment differences in fasting NEFA composition occurred on day 29. During the OGTT and 0-1 h following breakfast there was an increase in plasma long-chain saturated NEFA but a decrease in monounsaturated NEFA (microg/100 microg total NEFA; P<0.001). Between 1 and 3 h following breakfast treatment differences occurred for total saturated and total monounsaturated fatty acids (microg/100 microg total NEFA; P<0.05), expressed as an increase in 18 : 1 and decreases in 16 : 0 and 17 : 0 in treatment M relative to treatment L (P<0.05). Serum insulin attained 35 and 65 mU/l in treatments M and L respectively during this period. Negative correlations were found between 16 : 0 in fasting plasma and both waist:hip circumference (P=0.0009) and insulin response curve area during OGTT (within treatment M, P=0.0001). It is concluded that a normal postprandial insulin response is associated with a rapid change in plasma saturated:monounsaturated NEFA. It is proposed that this change is the result of a variable suppression of fat mobilization, which may partly account for a large difference in postprandial total plasma NEFA between fatty and carbohydrate meals.

Adult↗