Asbestos related mortality in Northern Ireland: 1985-1994

BACKGROUND

The association between Belfast and research into the hazardous effects of asbestos exposure goes back many years. This paper aims to update previous papers and review the burden of asbestos related disease in Northern Ireland today.

METHODS

A study was carried out of all deaths in Northern Ireland between 1985 and 1994 inclusive, in which an asbestos related disease was mentioned anywhere on the death certificate.

RESULTS

During this 10 year period, 527 asbestos related deaths were recorded; 88 per cent of these were in men. A total of 410 (77.8 per cent) were registered as the primary cause of death but only 405 (76.9 per cent) of cases were the subject of an autopsy. Standardized rates of pleural cancer in males have been increasing at 3.2 per cent per year though the trend was not significant. Lower rates in the last two years may herald the commencement of a decline. Deaths were clustered around the Belfast estuary, the site of Northern Ireland's shipbuilding industry. High proportional mortality ratios were demonstrated for occupations associated with the shipbuilding and construction industries. Evidence is presented that casts doubt on the attribution of peritoneal cancers in females to asbestos exposure. If lung cancers are included, there may be an average of 81 asbestos related deaths in Northern Ireland every year.

CONCLUSION

Asbestos related diseases continue to extract a heavy burden of ill health in Northern Ireland today. There are some indications that the upward trend may be on the wane but confirmation of this will have to await further data. Measures to reduce exposure in the workplace to both asbestos and to tobacco smoke are the only means of reducing this burden.

Pharmacokinetics and cerebrospinal fluid penetration of daunorubicin, idarubicin, and their metabolites in the nonhuman primate model

PURPOSE

Idarubicin (4-demethoxy-daunorubicin) is more potent and less cardiotoxic than the commonly used anthracyclines, doxorubicin and daunorubicin. In addition, idarubicin is metabolized to an active metabolite, idarubicinol, in contrast to other anthracyclines whose alcohol metabolites are much less active than the parent drug. The current study was performed in nonhuman primates to determine the plasma and cerebrospinal fluid (CSF) pharmacokinetics of idarubicin and idarubicinol and to compare them to the pharmacokinetics of daunorubicin and daunorubicinol.

METHODS

A dose of 30 mg/m2 of daunorubicin or 8 mg/m2 of idarubicin was administered intravenously over 15 minutes. Plasma and CSF were sampled frequently from the end of the infusion to 72 to 96 hours after infusion. Drug and metabolite concentrations were measured using high-pressure liquid chromatography (HPLC).

RESULTS

Daunorubicin elimination from plasma was triphasic with a terminal half-life of 5.9 +/- 1.8 hours, area under the concentration-time curve (AUC) 22.5 +/- 9.2 mumol/L.min, and clearance 2790 +/- 960 mL/min/m2. Daunorubicinol elimination was biphasic with a terminal half-life 10.2 +/- 2.3 hours and an AUC 74.5 +/- 5.3 mumol/L.min. Idarubicin elimination was triphasic with terminal half-life of 12.3 +/- 11.4 hours, a AUC 10.8 +/- 3.7 mumol/L.min, and clearance 1650 +/- 610 mL/min/m2. Idarubicinol elimination was biphasic with a terminal half-life 28.7 +/- 4.2 hours and AUC 67 +/- 9.8 mumol/L.min. CSF penetration was low for both parent drugs and their metabolites. CSF idarubicin was measurable at a single time point (1 hour after administration) for 2 animals, and was not measurable for the third. The CSF to plasma concentration ratio at that time point was 8% in 1 animal and 15% in the other. Idarubicinol was detected in 2 to 4 samples at various times, appearing as early as 1 hour in 1 animal and persisting as late as 48 hours in another. The CSF to plasma concentration ratio at corresponding time points was 1.9 +/- 0.6%. Daunorubicin was measurable for < 6 hours after intravenous administration. For individual animals, the mean CSF to plasma concentration ranged from 4% to 12%. Daunorubicinol was detectable by 1 hour in 2 of 3 animals and by 3 hours in the other, and remained detectable at 24 hours in 2 of 3. The terminal half-life of daunorubicinol in CSF was 8.8 +/- 1.3 hours, the AUC was 1.8 +/- 1.5 mumol/L.min, and the AUCCSF to AUCplasma ratio was 2.4 +/- 1.9%.

CONCLUSION

Idarubicin, idarubicinol, daunorubicin, and daunorubicinol penetrate poorly into the CSF after intravenous administration.

Association of spatial distribution of childhood respiratory morbidity with environmental dust pollution

The objective of this study was to investigate the spatial distribution of respiratory morbidity and asthma in children in relation to high levels of airborne dust pollution. A cross-sectional survey of 2035 children (aged 5-11 yr) by parent-completed questionnaire, with concurrent monitoring of dust deposition rates in the vicinity of children's homes, was performed in 15 primary schools (5 in each of 3 areas of Merseyside). The main outcome measures were (1) doctor-diagnosed asthma, (2) parent-reported respiratory symptoms of recent excess cough, wheeze, and breathlessness, and (3) school absenteeism due to respiratory ill health. Proximity to the source of dust pollution was associated with increased prevalence of excess cough, breathlessness, school absence due to respiratory ill health, and doctor-diagnosed asthma, after adjusting for a range of socioeconomic, environmental, and other confounding factors. The adjusted odds for excess cough and breathlessness for children living within 2 km of the source (dock area) are estimated to be almost twice those for children living more than 2 km away: excess cough 1.9 (95% CI 1.4-2.6); breathlessness 1.9 (1.3-2.7); school absence 1.5 (1.2-1.9); and doctor-diagnosed asthma 1.5 (1.1-2.0). Excess cough was significantly associated with the mean annual dust deposition recorded in the vicinity of the child's home. The adjusted odds ratio for excess cough corresponding to an increase in mean annual dust deposition of 50 mg/m2/d was 3.1 (95% CI 1.1-8.2). These results suggest that airborne dust was associated with respiratory morbidity in these children, which could relate to the high prevalence of childhood doctor-diagnosed asthma in this community.

Relationship between physiological factors and clinical pain in dogs scored using a numerical rating scale

A study was designed to investigate the association between heart rate, respiratory rate and pupil dilation and a subjective pain score allocated using a numerical rating scale (NRS). Four groups of dogs (n = 17 to 20 per group) were included: orthopaedic surgery cases, soft tissue surgery cases, dogs with medical conditions and healthy dogs. Each dog was examined by five veterinary surgeons within a four-hour period. When examining each dog, the observers recorded heart rate, respiratory rate, pupil dilation (present or absent) and a pain score using a NRS (range 0 to 10). For surgical cases, all study assessments were carried out between 21 and 27 hours following the end of surgery. The correlation coefficients between physiological parameters and NRS score were small but, depending on the analysis, were significant for heart rate and NRS score (P < 0.05). However, the size of the coefficient, 0.168, indicated that the relationship was not biologically significant. There was no association between respiratory rate and NRS score. Analysis of the relationship between NRS score and pupil dilation indicated that there was an association between this factor and pain, depending on the analysis. This was significant for the surgical groups (P < 0.05) but not for the other groups. These findings indicate that heart rate and respiratory rate are not useful indicators of pain in hospitalised dogs. It is also unlikely that pupil dilation will be a useful tool in the assessment of pain.

The diagnosis and initial treatment of asthma in young children in New Zealand and the United Kingdom

AIMS

To conduct a pilot study to test methodology in ascertaining if there are differences between New Zealand and the UK in the symptom and circumstance set that influences a general practitioner in the initial diagnosis of asthma, and to ascertain the treatment prescribed at the time that the diagnosis is made.

METHODS

Questionnaires were mailed to 110 general practitioners in each country. General practitioners from the Otago region in New Zealand and from the Nottingham region in Britain were contacted. A follow-up reminder was sent to all non-responders three weeks after the initial mail out. Questions were asked about the symptoms and signs that were considered important, as well as other influences (e.g., passive smoking) when making a diagnosis of asthma in a child under the age of five years. The doctors were also asked what treatment they prescribed at the time of the actual diagnosis of asthma.

RESULTS

British doctors considered night cough (p = 0.05) and cough associated with emotion (p = 0.004) more diagnostic of asthma. New Zealand doctors rated cough associated with temperature change (p = 0.05) as being important and they had a lower threshold in diagnosing asthma with respect to history of similar attacks (p = 0.008) compared to their British counterparts. More New Zealand doctors reported using prophylactic/anti-inflammatory agents as first line therapy (59% vs 28%; p = 0.002).

CONCLUSIONS

We conclude that there are only minor differences in general practitioners' diagnostic criteria for asthma in the two countries with reference to this small sample. We believe, however, that differing diagnostic criteria could account for different reported incidences of childhood asthma in some countries. There is need for internationally accepted diagnostic criteria.

Risk factors associated with alterations in carotid intima-media thickness in hypertension: baseline data from the European Lacidipine Study on Atherosclerosis

BACKGROUND

The possibility that calcium antagonists exert an anti-atherosclerotic action at least partly independently of the blood-pressure-lowering effect is supported by results of a large number of experimental studies and can now be investigated by quantitative B-mode ultrasound imagining of the carotid artery walls.

DESIGN

The European Lacidipine Study on Atherosclerosis (ELSA) is a prospective, randomized, double-blind, multinational trial comparing effects of 4-year treatment based on the long-acting, highly lipophilic calcium antagonist lacidipine with those of treatment based on the beta-blocker atenolol on the development of carotid artery wall alterations in patients (aged 45-75 years) with mild-to-moderate hypertension (systolic blood pressure 150-210 mmHg and diastolic blood pressure 95-115 mmHg). While the intervention study is progressing, this article summarizes baseline data obtained from the whole cohort of 2259 patients randomly allocated to treatment.

METHODS

Baseline ultrasound data were obtained from two replicate examinations performed shortly before random allocation to treatment by certified sonographers at 23 referral centres and read at the ultrasound coordinating centre at the Wake Forest University School of Medicine. Intima-media thickness was measured at up to 12 different sites in the carotid artery tree and expressed as the mean of the maxima at these sites (Mmax), the mean of the maxima at four sites in the distal common carotid artery and bifurcation (CBMmax) and the maximum intima-media thickness (Tmax). Baseline demographic and clinical measurements were performed by investigators in 410 peripheral clinical units and 24 h ambulatory blood pressure monitorings read and validated by members of a centralized unit at the University of Milan. The statistical analysis centre at the Technische Universität München received and analysed all baseline data, by calculating means +/- SD, medians and ranges and performing correlation (Spearman correlation coefficients) and multiple regression analyses.

RESULTS

Prevalence of carotid artery wall alterations among the hypertensive patients randomly allocated to treatment in the ELSA was very high: 82% had Tmax > or = 1.3 mm ('plaques' according to protocol) and 17% had Tmax > or = 1.0 and < 1.3 mm ('thickening'), with a median of two plaques per patient. We found significant correlations between ultrasound measurements and the following demographic and clinical variables: age, sex, systolic blood pressure and pulse pressure (both clinic and ambulatory), concentrations of total, high-density lipoprotein and low-density lipoprotein cholesterol and triglycerides, smoking habit and duration of hypertension. We found no significant correlation to diastolic blood pressure and glucose concentration. A multiple regression analysis indicated significant variables in the following rank order: age, 24 h ambulatory pulse pressure, sex, low-density lipoprotein cholesterol concentration, triglyceride concentration, smoking and clinic systolic blood pressure.

CONCLUSIONS

Analysis of baseline data from the ELSA has shown that there is an extremely marked prevalence of carotid artery wall alterations among mild-to-moderate, middle-aged hypertensive patients. In addition to age, systolic blood pressure and pulse pressure, particularly if they are accurately measured by ambulatory monitoring, play a major role, somewhat greater than those of sex, low-density lipoprotein cholesterol concentration and smoking, in influencing intima-media thickness.

Serum sickness-like reaction to cefaclor: lack of in vitro cross-reactivity with loracarbef

OBJECTIVES

A lymphocyte-based in vitro rechallenge technique was used to examine the potential for cross-reactivity between loracarbef and cefaclor in children who had had adverse reactions to cefaclor.

STUDY DESIGN

The study cohort included 10 patients (2.2 +/- 1.1 years old) with a serum sickness-like reaction to cefaclor, five patients (4.1 +/- 4.6 years old) with immediate-type hypersensitivity reactions to the drug, and five patients (1.5 +/- 0.9 years old) who had a delayed hypersensitivity reaction to cefaclor without joint involvement (i.e., not a serum sickness-like reaction). Peripheral blood mononuclear cells were isolated from each patient and were exposed to cefaclor, loracarbef, and the metabolites of each generated with phenobarbital-induced murine hepatic microsomes.

RESULTS

Among patients with cefaclor-associated serum sickness-like reactions, lymphocyte killing (expressed as percentage cell kill above baseline) in the presence of cefaclor metabolites (83.6% +/- 42.2%) was significantly (p < 0.02) higher than that observed among the patients with either immediate-type (1.1% +/- 2.4%) or delayed hypersensitivity (0%) reactions. In contrast, loracarbef did not produce significant in vitro cytotoxicity among any of the patient subgroups. Our in vitro evidence was supported at therapeutic rechallenge with loracarbef among three children with cefaclor-associated serum sickness-like reactions who tolerated a full course of therapy without adverse reactions.

CONCLUSION

The metabolite-mediated cytotoxicity associated with cefaclor among patients who had had serum sickness-like reactions after therapeutic administration of the drug was not shared with loracarbef. The extent to which the apparent lack of in vitro cross-reactivity between cefaclor and loracarbef may be predictive of clinical cross-reactivity is not known.

Impact of the October 1995 pill scare in Grampian

Over two years have elapsed since the Department of Health issued a press release concerning the safety of some third generation contraceptive pills. Warnings about increased abortion rates followed and recently published national figures for England and Wales have confirmed this. In Grampian we have assessed the impact of the pill scare at a subnational level, which has received much less consideration. Grampian has a stable population with an estimated 116,500 women in the reproductive years. The six month period from November 1995 until April 1996 was chosen to monitor the immediate aftermath of the pill scare. Aberdeen Royal Infirmary provides a regional, dedicated abortion service and has maintained a service specific database since 1994. This is an ideal situation to monitor trends in abortion rates in a specific population. Women attending for abortion counselling were asked to complete a questionnaire regarding their recall of media publicity. Live-births at Aberdeen Maternity Hospital from June to November 1996 were also recorded, reflecting conceptions in the study period. Prescribing patterns for combined pills and emergency contraception for Grampian general practitioners and Grampian Healthcare family planning service were also analysed. There was no increase in the abortion rate in the study period when compared with the same period in the preceding year - a total of 728 women underwent an abortion. Forty six women were identified within the 728 as having conceived as a direct consequence of the scare, but their characteristics were not dissimilar to the other women on the database. Live-birth rates were also stable. Emergency contraception prescribing was slightly increased for the family planning service but not in general practice. Both general practice and the family planning service showed an immediate and sharp fall in prescribing of third generation pills mirrored by an increase in second generation pill prescribing. For family planning particularly, prescriptions for third generation pills have shown an increase again from early 1996, although remaining below original levels. Fifty five per cent of the women who were given the questionnaire about media publicity responded. Seventy nine per cent recalled some publicity, but 17 per cent of these women could not remember any specific details. Unlike national reporting, our figures do not substantiate any increase in abortions or deliveries in the aftermath of the pill scare. The slight increase in emergency contraception prescribing by the family planning service more probably reflects local awareness campaigns rather than any appreciable switch away from regular pill use. On a population level, the scare did not have the predicted negative impact on pill users in Grampian and it would have been incorrect for us to extrapolate from national data in this instance. Failure to demonstrate numerical impact for the population does not deny the devastating effect of a termination for an individual woman. The emotional impact of the scare on women, while more difficult to measure, should not be underestimated. The influence on the next generation of women with regard to their contraceptive choice remains to be seen.

Blanket bans on treatment: conflict in healthcare resourcing

Blanket bans of specific treatments have been controversially introduced by some NHS trusts as a means of rationing health care and prioritizing funding for services. This article examines the perceived value conflicts that emerge in relation to blanket bans on specific treatments. Following an initial overview of rationing in contemporary society the needs and wants of given individuals are compared with those of a wider society. Ethical values and philosophical considerations are explored as an analysis of the continuing debate is attempted.

Comparison of three methods used for assessment of pain in dogs

OBJECTIVE

To investigate the reliability of 3 scales used for assessment of pain in dogs.

DESIGN

Prospective study.

ANIMALS

50 dogs that had surgery.

PROCEDURE

Dogs were allocated into 3 groups (group 1, 25 dogs assessed 1 hour after the end of surgery; group 2, 41 dogs assessed between 21 and 27 hours after the end of surgery; group 3, 16 dogs assessed on the day of surgery and on the subsequent day). Each dog was scored for pain 4 times by 3 (groups 1 and 3) or 4 (group 2) veterinarians, using all 3 scales (i.e. simple descriptive, numerical rating, and visual analogue) during each scoring period. Analysis of data was performed using ANOVA, log-linear modeling, calculation of reproducibility coefficients, and Cohen's kappa statistic.

RESULTS

Significant variability existed among observers for use of all 3 scales. Variability among observers and between observers and dogs accounted for 29 to 36% of the total variability (group 1, 36.1 and 32.3% and group 2, 35.1 and 29.7%, for visual analogue scale and numerical rating scale scores, respectively). Kappa statistic values calculated for data obtained by use of the simple descriptive scale indicated that agreement was fair for the observers (group 1, 0.244 to 0.299; group 2, 0.211 to 0.368; group 3, 0.233 to 0.321).

CLINICAL IMPLICATIONS

Analysis of pain score data in dogs must incorporate observer variability when more than 1 observer is used. Comparative analysis of data accrued from pain studies in various hospitals must account for this variability.

Circulating anti-(xanthine oxidoreductase) antibodies in healthy human adults

Levels of free anti-(xanthine oxidoreductase) (XOR) antibodies in the serum of normal healthy human subjects were determined, using both human and bovine enzyme as antigen, in an enzyme-linked immunosorbent assay (ELISA). Levels of IgM class anti-(human XOR) antibodies were found to be particularly high (mean values representing approximately 3% of total IgM) and to be significantly higher than levels of IgM anti-(bovine XOR) antibodies, indicating that endogenous XOR, rather than ingested bovine milk XOR, is the immunogen. IgM anti-XOR antibody levels were significantly higher in women under 50 years than in age-matched men, or in older women. Levels of IgG class anti-XOR antibodies were much lower and showed no correlation with gender or age. Affinity-purified anti-(human XOR) antibodies only partially inhibited enzymic activities of XOR. The majority of both IgM and IgG anti-(human XOR) antibodies in serum occurred as immune complexes, suggesting that the specific antibodies have a protective role in removing potentially damaging XOR from the circulation.

Analysis of the ligand binding site of the 5-HT3 receptor using site directed mutagenesis: importance of glutamate 106

The 5-HT3 receptor is a ligand-gated ion channel with significant structural similarity to the nicotinic acetylcholine receptor. Several regions that form the ligand binding site in the nicotinic acetylcholine receptor are partially conserved in the 5-HT3 receptor, presumably reflecting the conserved signal transduction mechanism. Specific amino acid differences in these regions may account for their distinct ligand recognition properties. Using site-directed mutagenesis, we have replaced one of these residues, glutamate 106 (E106), with aspartate (D), asparagine (N), alanine (A) or glutamine (Q) and characterized the ligand-binding and electrophysiological properties of the mutant receptors after transient expression in HEK-293 cells. The affinity for the selective 5-HT3 receptor antagonist [3H]GR65630 was decreased 14-fold in the mutant E106D (Kd = 3.69 +/- 0.32 nM) when compared to wildtype (WT, E106) 5-HT3 receptor (0.27 +/- 0.03 nM), while the affinity for E106N was unchanged (0.42 +/- 0.07 nM, means +/- SEM, n = 3-10). Decreased affinities for both E106D and E106N were observed for the antagonists granisetron, ondansetron and renzapride and for the agonists 5-HT (130- and 30-fold) and 2-methyl-5-HT (250- and 20-fold), respectively. Both mutants still formed 5-HT-activatable ion channels, but the high Hill coefficient of the concentration effect curves in wildtype (2.0) was decreased to unity in both cases. The EC50 of 5-HT was increased seven-fold in E106N (8.7 microM) when compared to wildtype (1.2 microM), but unchanged in E106D, and the potency of the antagonist ondansetron for both mutants was decreased. E106A and E106Q expressed poorly preventing a detailed characterization. These data suggest that E106 contributes to the ligand-binding site of the 5-HT3 receptor and may form an ionic or hydrogen bond interaction with the primary ammonium group of 5-HT.

Can audit of a local protocol for the management of lipid disorders effect and detect a change in clinical practice?

OBJECTIVE

To audit the implementation of a local protocol for the management of lipid disorders in Grampian.

INTERVENTION

A local protocol for the detection and management of lipid disorders, developed by a multi-disciplinary group and based on available national guidelines and systematic reviews, was disseminated and implemented using the audit cycle.

DESIGN

An uncontrolled before and after study using four surveys of different aspects of lipid management in primary and secondary care.

RESULTS

There was evidence of change in clinical practice following protocol implementation. Improvements in patient care were identified. However, some areas of inappropriate practice remained unaltered. Changes in dietary therapy indicated an improvement in the appreciation of the importance of appropriate dietary advice. There was an increase in the proportion of patients who were appropriately screened and managed, and appropriately referred to the lipid clinic. The health status of patients being screened/treated following guidelines was poorer suggesting a reduction in screening of low risk patients and an increase in lipid assessment of patients with other health problems or risk factors i.e. more appropriate screening. However, after the protocol was disseminated, general practitioners screened less often for secondary causes of hyperlipidaemia.

A pharmacodynamic study of propofol or propofol and ketamine infusions in ponies undergoing surgery

The pharmacodynamics of infusions of propofol alone (group 1) were compared with the pharmacodynamics of infusions of propofol and ketamine together (group 2) in eight ponies undergoing castration. Anaesthesia was induced with detomidine, 20 micrograms kg-1, followed by ketamine, 2.2 mg kg-1. Subsequently, a bolus dose of propofol, 0.5 mg kg-1, was administered intravenously to both groups, and an infusion of propofol was given for an average of 74 minutes to group 1, and an infusion of propofol and ketamine was given for 60 minutes to group 2. The mean (SD) infusion rates of propofol were 0.330 (0.050) mg kg-1 min-1 in group 1, and 0.124 (0.009) mg kg-1 in group 2, and the ketamine infusion rate was maintained constant at 40 micrograms kg-1 min-1. Arterial hypotension and marked respiratory depression were evident in some of the ponies receiving propofol alone, whereas in the ponies anaesthetised with propofol and ketamine, respiratory and cardiovascular parameters were well maintained. All the ponies in both groups recovered quickly from anaesthesia, with mean times to sternal recumbency and standing of 19.8 (8.0) minutes and 27.2 (7.4) minutes respectively for group 1 and 8.4 (3.2) min and 14.9 (10.1) minutes for group 2.

Using action cards to improve resuscitation response

This article highlights how the process of change applied to resuscitation procedures was carried out in a clinical area. The project involved assessing the effectiveness of using action cards which clearly identify each nurse's role and responsibilities during resuscitation.

Administration to innovation: the evolving management challenge in primary care

The concept of the primary health-care team involving an increasingly diverse range of health care professionals is widely recognized as central to the pursuit of a primary care-led health service in the UK. Although GPs are formally recognized as the team leaders, there is little by way of policy prescription as to how team roles and relationships should be developed, or evidence as to how their roles have in fact evolved. Thus the notion of the primary health-care team while commonly employed, is in reality lacking definition with the current contribution of practice managers to the operation of this team being poorly understood. Focusing on the career backgrounds of practice managers, their range of responsibilities, and their involvement in innovation in general practice, presents a preliminary account of a chief scientist office-funded project examining the role being played by practice managers in primary health-care innovation. More specifically, utilizing data gained from the ongoing study, contextualizes the role played by practice managers in the primary health-care team. By exploring the business environment surrounding the NHS general practice, the research seeks to understand the evolving world of the practice manager. Drawing on questionnaire data, reinforced by qualitative data from the current interview phase, describes the role played by practice managers in differing practice contexts. This facilitates a discussion of a set of ideal type general practice organizational and managerial structures. Discusses the relationships and skills required by practice managers in each of these organizational types with reference to data gathered to date in the research.