Occupational asthma caused by peracetic acid-hydrogen peroxide mixture

BACKGROUND

Healthcare practice in the UK has moved away from using aldehyde disinfectants for the decontamination of endoscopes, in part due to the risk of respiratory sensitization. Peracetic acid (PAA) in combination with hydrogen peroxide (HP) is a commonly used alternative.

AIM

We describe a case of occupational asthma (OA) diagnosed at our specialist occupational lung disease clinic and caused by occupational exposure to PAA-HP mixture, used as a disinfectant in an endoscope washer-disinfector machine.

CASE REPORT

A 48-year-old man employed as a mycologist and environmental microbiologist at a Birmingham city hospital, UK, presented following an acute exposure to PAA-HP mixture causing lacrimation, burning optic pain and headache. He had also experienced symptoms suggestive of OA for the preceding 10 months, and the diagnosis was confirmed through OASYS analysis of serial peak expiratory flow measurements. He had been exposed to PAA-HP mixture whilst working in the endoscopy department for 12 months prior to the acute episode, and a subsequent specific inhalation challenge test was positive with a late asthmatic response to PAA-HP mixture.

CONCLUSION

This case provides evidence for a sensitization mechanism in OA caused by PAA-HP mixture.

Cleaning agent occupational asthma in the West Midlands, UK: 2000-16

Background

Cleaning agents are now a common cause of occupational asthma (OA) worldwide. Irritant airway and sensitization mechanisms are implicated for a variety of old and new agents.

Aims

To describe the exposures responsible for cleaning agent OA diagnosed within a UK specialist occupational lung disease service between 2000 and 2016.

Methods

The Birmingham NHS Occupational Lung Disease Service clinical database was searched for cases of OA caused by cleaning agents, and data were gathered on age, gender, atopic status, smoking history, symptom onset, diagnostic investigations (including Occupational Asthma SYStem analysis of workplace serial peak expiratory flow measurements and specific inhalational challenge), proposed mechanism, industry, occupation and causative agent.

Results

Eighty patients with cleaning agent OA (77% female, 76% arising de novo) were identified. The median annual number of cases was 4 (interquartile range = 2-7). The commonest cleaning agents causing OA were chloramines (31%), glutaraldehyde (26%) and quaternary ammonium compounds (11%) and frequently implicated industries were healthcare (55%), education (18%) and leisure (8%).

Conclusions

Certain cleaning agents in common usage, such as chlorine-releasing agents, quaternary ammonium compounds and aldehydes, are associated with sensitization and asthma. Their use alters over time, and this is particularly evident in UK healthcare where cleaning and decontamination practice and policy have changed. Vigilance for OA in workplaces such as hospitals, nursing homes, leisure centres and swimming pools, where these cleaning agents are regularly used, is therefore essential.

Asbestosis is prevalent in a variety of construction industry trades

A diagnosis of asbestosis, which is a long-latency, fibrotic lung disease, has implications for the patient in terms of prognosis, treatment and compensation. Identifying and quantifying asbestos exposure is difficult without a detailed occupational history, and the threshold dose of asbestos required to cause asbestosis is not well understood. We reviewed all cases of asbestosis diagnosed between 2001 and 2016 at the Birmingham Regional NHS Occupational Lung Disease Service to determine the industries and occupations most frequently implicated in causation, in order to help clinicians identify where asbestosis might enter the differential diagnosis for a patient with chronic respiratory symptoms. A variety of construction trades were frequently reported including carpenters and joiners, pipe fitters, laggers, labourers, painters and shop fitters. Traditionally heavily exposed occupations such as shipbuilding were not commonly seen.

Occupational asthma caused by acrylic compounds from SHIELD surveillance (1989-2014)

Background

Acrylic monomers (acrylates), methacrylates and cyanoacrylates all cause asthma by respiratory sensitization. Occupational inhalation exposures occur across a variety of industries including health care and dental work, beauty, laboratory science, assembly and plastic moulding.

Aims

To examine notifications of occupational asthma caused by acrylic compounds from a UK-based regional surveillance scheme, in order to highlight prevalent exposures and trends in presentation.

Methods

Retrospective review of all cases reported to the SHIELD surveillance scheme for occupational asthma, West Midlands, UK between 1989 and 2014. Patient data were gathered on demographics, employment, asthma symptoms and diagnostic investigations including serum immunological testing, serial peak flow analysis and specific inhalation challenge tests. Descriptive statistics were used to illustrate worker characteristics and evidence for sensitization to acrylic compounds.

Results

There were 20 affected patients out of 1790 total cases of occupational asthma (1%); all cases were confirmed by OASYS (Occupational Asthma SYStem) analysis of serial peak flow measurements, with three additional positive specific inhalation challenge tests. Three out of 20 (15%) patients were current smokers and 11/20 (55%) were atopic. A variety of exposures and industries were implicated including: manufacturing, health care, beauty and printing and a novel presentation seen in teachers exposed to floor adhesives.

Conclusions

This is the largest reported series of occupational asthma caused by acrylic compounds, which remain an important aetiological factor in this disease. Exposure occurs in a variety of industries, particularly in manufacturing and is seen with other, perhaps better recognized sensitizing agents such as isocyanates and epoxy resins.

Dramatic elevation in urinary amino terminal titin fragment excretion quantified by immunoassay in Duchenne muscular dystrophy patients and in dystrophin deficient rodents

Enzyme-linked and electrochemiluminescence immunoassays were developed for quantification of amino (N-) terminal fragments of the skeletal muscle protein titin (N-ter titin) and qualified for use in detection of urinary N-ter titin excretion. Urine from normal subjects contained a small but measurable level of N-ter titin (1.0 ± 0.4 ng/ml). A 365-fold increase (365.4 ± 65.0, P = 0.0001) in urinary N-ter titin excretion was seen in Duchene muscular dystrophy (DMD) patients. Urinary N-ter titin was also evaluated in dystrophin deficient rodent models. Mdx mice exhibited low urinary N-ter titin levels at 2 weeks of age followed by a robust and sustained elevation starting at 3 weeks of age, coincident with the development of systemic skeletal muscle damage in this model; fold elevation could not be determined because urinary N-ter titin was not detected in age-matched wild type mice. Levels of serum creatine kinase and serum skeletal muscle troponin I (TnI) were also low at 2 weeks, elevated at later time points and were significantly correlated with urinary N-ter titin excretion in mdx mice. Corticosteroid treatment of mdx mice resulted in improved exercise performance and lowering of both urinary N-ter titin and serum skeletal muscle TnI concentrations. Low urinary N-ter titin levels were detected in wild type rats (3.0 ± 0.6 ng/ml), while Dmd^mdx rats exhibited a 556-fold increase (1652.5 ± 405.7 ng/ml, P = 0.002) (both at 5 months of age). These results suggest that urinary N-ter titin is present at low basal concentrations in normal urine and increases dramatically coincident with muscle damage produced by dystrophin deficiency. Urinary N-ter titin has potential as a facile, non-invasive and translational biomarker for DMD.

Can serial PEF measurements separate occupational asthma from allergic alveolitis?

BACKGROUND

Occupational asthma commonly results in work-related changes in serial peak expiratory flow (PEF) measurements. Whether alveolitis can result in similar changes is unknown.

AIMS

To identify differences and similarities of serial PEF between workers with occupational alveolitis and asthma seen during an outbreak investigation in a factory with metal-working fluid exposure.

METHODS

Workers with respiratory symptoms and rest-day improvement were identified by questionnaire. Each was asked to measure PEF 8 times daily for 4 weeks at home and work. Alveolitis was subsequently diagnosed from a validated scoring system including radiological changes, carbon monoxide diffusing capacity, bronchoalveolar lavage and biopsy results. Occupational asthma was confirmed with a positive Oasys score >2.5 and a mean rest-work PEF >16 l/min from serial 2-hourly PEF measurements. The Oasys PEF plotter calculated differences between rest and workdays for mean PEF, diurnal variation and the scores were used to confirm an occupational effect (Oasys, area between curve and time point). Records were compared between the alveolitis group and the group with occupational asthma without alveolitis.

RESULTS

Forty workers with occupational asthma and 16 with alveolitis had indistinguishable PEF changes on workdays in terms of magnitude (median reduction 18.5 and 16.1 l/min, respectively) and diurnal variation. Immediate reactions were more common with occupational asthma and late reactions more common with alveolitis.

CONCLUSIONS

PEF responses to metal-working fluid aerosols do not distinguish occupational asthma from alveolitis except in timing. They can be used to identify the workplace as the cause of asthma and also alveolitis.

Robust Translation of γ-Secretase Modulator Pharmacology across Preclinical Species and Human Subjects

The amyloid-β peptide (Aβ)—in particular, the 42–amino acid form, Aβ1-42—is thought to play a key role in the pathogenesis of Alzheimer’s disease (AD). Thus, several therapeutic modalities aiming to inhibit Aβ synthesis or increase the clearance of Aβ have entered clinical trials, including γ-secretase inhibitors, anti-Aβ antibodies, and amyloid-β precursor protein cleaving enzyme inhibitors. A unique class of small molecules, γ-secretase modulators (GSMs), selectively reduce Aβ1-42 production, and may also decrease Aβ1-40 while simultaneously increasing one or more shorter Aβ peptides, such as Aβ1-38 and Aβ1-37. GSMs are particularly attractive because they do not alter the total amount of Aβ peptides produced by γ-secretase activity; they spare the processing of other γ-secretase substrates, such as Notch; and they do not cause accumulation of the potentially toxic processing intermediate, β-C-terminal fragment. This report describes the translation of pharmacological activity across species for two novel GSMs, (S)-7-(4-fluorophenyl)-N2-(3-methoxy-4-(3-methyl-1H-1,2,4-triazol-1-yl)phenyl)-N4-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidine-2,4-diamine (BMS-932481) and (S,Z)-17-(4-chloro-2-fluorophenyl)-34-(3-methyl-1H-1,2,4-triazol-1-yl)-16,17-dihydro-15H-4-oxa-2,9-diaza-1(2,4)-cyclopenta[d]pyrimidina-3(1,3)-benzenacyclononaphan-6-ene (BMS-986133). These GSMs are highly potent in vitro, exhibit dose- and time-dependent activity in vivo, and have consistent levels of pharmacological effect across rats, dogs, monkeys, and human subjects. In rats, the two GSMs exhibit similar pharmacokinetics/pharmacodynamics between the brain and cerebrospinal fluid. In all species, GSM treatment decreased Aβ1-42 and Aβ1-40 levels while increasing Aβ1-38 and Aβ1-37 by a corresponding amount. Thus, the GSM mechanism and central activity translate across preclinical species and humans, thereby validating this therapeutic modality for potential utility in AD.

Twenty years of SHIELD: decreasing incidence of occupational asthma in the West Midlands, UK?

INTRODUCTION

Since 2000 a decline in the incidence of occupational asthma (OA) has been reported in the UK and Europe. We aimed to describe and account for trends in the incidence of OA in the West Midlands, UK using annual notification data from the SHIELD voluntary surveillance scheme over the period 1991-2011.

METHODS

All notifications to the SHIELD database between January 1991 and December 2011 were identified, along with patients' demographic data, occupations, causative agents and confirmatory tests. Annual notifications were scaled to give an annual count per million workers, giving a measure of incidence, and also standardised against those of bakers' asthma. Non-parametric analyses were undertaken between annual incidence and time (years) for common causative agents using (1) a negative binomial regression univariate model and (2) a logistic regression model calculating annual reporting ORs. A step-change analysis was used to examine time points at which there were marked reductions in incidence.

RESULTS

A decrease in annual incidence of OA was observed over the study period (incident rate ratio=0.945; 95% CI 0.933 to 0.957; p<0.0001), an effect that was lost after standardising for bakers' asthma. Decreases in incidence were seen for most common causative agents, with only cleaning product-related OA increasing over 21 years. Marked fall in incidence was seen in 2004 for isocyanates, and in 1995 for latex. Most notifications came from a regional specialist occupational lung disease unit, with notifications from other sites falling from 16 cases/million workers/annum in 1995 to 0 in 2004.

CONCLUSIONS

Reporter fatigue and increasing under-recognition of OA are both factors which contribute to the apparent fall in incidence of OA in the West Midlands. There is a future need for interventions that enable health professionals to identify potential cases of OA in the workplace and in healthcare settings.

Identification and Preclinical Pharmacology of the γ-Secretase Modulator BMS-869780

Alzheimer's disease is the most prevalent cause of dementia and is associated with accumulation of amyloid-β peptide (Aβ), particularly the 42-amino acid Aβ1-42, in the brain. Aβ1-42 levels can be decreased by γ-secretase modulators (GSM), which are small molecules that modulate γ-secretase, an enzyme essential for Aβ production. BMS-869780 is a potent GSM that decreased Aβ1-42 and Aβ1-40 and increased Aβ1-37 and Aβ1-38, without inhibiting overall levels of Aβ peptides or other APP processing intermediates. BMS-869780 also did not inhibit Notch processing by γ-secretase and lowered brain Aβ1-42 without evidence of Notch-related side effects in rats. Human pharmacokinetic (PK) parameters were predicted through allometric scaling of PK in rat, dog, and monkey and were combined with the rat pharmacodynamic (PD) parameters to predict the relationship between BMS-869780 dose, exposure and Aβ1-42 levels in human. Off-target and safety margins were then based on comparisons to the predicted exposure required for robust Aβ1-42 lowering. Because of insufficient safety predictions and the relatively high predicted human daily dose of 700 mg, further evaluation of BMS-869780 as a potential clinical candidate was discontinued. Nevertheless, BMS-869780 demonstrates the potential of the GSM approach for robust lowering of brain Aβ1-42 without Notch-related side effects.

Cobalt asthma in metalworkers from an automotive engine valve manufacturer

BACKGROUND

Cobalt asthma has previously been described in cobalt production workers, diamond polishers and glassware manufacturers.

AIMS

To describe a case series of occupational asthma (OA) due to cobalt, identified at the Birmingham Heartlands Occupational Lung Disease Unit, West Midlands, UK.

METHODS

Cases of cobalt asthma from a West Midlands' manufacturer of automotive engine valves, diagnosed between 1996 and 2005, were identified from the SHIELD database of OA. Case note data on demographics, employment status, asthma symptoms and diagnostic tests, including spirometry, peak expiratory flow (PEF) measurements, skin prick testing (SPT) and specific inhalational challenge (SIC) tests to cobalt chloride, were gathered, and descriptive statistics used to illustrate the data.

RESULTS

The natural history of presentations has been described in detail, as well as a case study of one of the affected workers. Fourteen metalworkers (86% male; mean age 44.9 years) were diagnosed with cobalt asthma between 1996 and 2005. Workers were principally stellite grinders, stellite welders or machine setter-operators. All workers had positive Occupational Asthma SYStem analyses of serial PEF measurements, and sensitization to cobalt chloride was demonstrated in nine workers, by SPT or SIC.

CONCLUSIONS

We have described a series of 14 workers with cobalt asthma from the automotive manufacturing industry, with objective evidence for sensitization. Health care workers should remain vigilant for cobalt asthma in the automotive manufacturing industry.

An outbreak of occupational asthma due to chromium and cobalt

BACKGROUND

Five metal turners employed by an aerospace manufacturer presented to the Birmingham Chest Clinic occupational lung disease unit. Four cases of occupational asthma (OA) due to chromium salt (3) and cobalt (1) were diagnosed by serial peak-expiratory flow measurements and specific inhalation challenge testing.

AIMS

To measure the extent of the outbreak and to provide epidemiological data to ascertain the aetiology.

METHODS

Participants answered a detailed, self-administered questionnaire, designed to detect occupational lung disease. Urine chromium and cobalt excretion, spirometry and exhaled nitric oxide measurements were taken. Those with possible, probable or definite non-OA or OA, after questionnaire, were invited to undertake two-hourly peak flow measurements and received specialist follow-up.

RESULTS

A total of 62 workers (95% of workforce) participated. Sixty-one per cent of employees were working in higher metalworking fluid (MWF) exposure areas. Ninety per cent of workers had urinary chromium excretion indicating occupational exposure. Sixty-six per cent of workers reported active respiratory symptoms, although there were no significant differences between exposure groups. Two further workers with probable OA were identified and had significantly higher urinary chromium and cobalt concentration than asymptomatic controls. Eighteen cases of occupational rhinitis (OR) were identified, with significantly raised urinary chromium concentration compared with asymptomatic controls.

CONCLUSIONS

Chromium salt and cobalt can be responsible for OA and OR in workers exposed to MWF aerosols. Onset of symptoms in those with positive specific challenges followed change in MWF brand. Workers with OA had increased urinary concentrations of chromium and cobalt, and those with OR had increased urinary concentrations of chromium.

Shift work effects on serial PEF measurements for occupational asthma

BACKGROUND

Diurnal variation (DV) affects lung function but the changes are thought to be related to sleep patterns rather than time of day. When diagnosing occupational asthma (OA), serial peak expiratory flow (PEF) measurements are the recommended first line investigation, but could be confounded by shift work.

AIMS

The aim of the study was to investigate the effects of shift work on PEF measurements used for diagnosing OA.

METHODS

PEF records containing more than one shift pattern with ≥ 4 days per shift were identified. OA diagnosis was based on an Oasys-2 score ≥ 2.51 and non-OA on having an alternative clinical diagnosis and Oasys-2 score <2.51. The mean area between curves (ABC) score, mean PEF DV and cross-shift PEF changes were calculated for each shift.

RESULTS

Records from 123 workers with OA and 69 without OA satisfied inclusion criteria. In the OA group, PEF declined more on afternoon and night shifts than days (P < 0.001). The ABC score was lower in the OA group on night (P < 0.05) and afternoon shifts (P < 0.05) as compared with days, without significant differences in DV. Among those without OA, cross-shift PEF increased more on day shifts (mean + 25 l/min) than afternoon or night shifts (+1 l/min) (P < 0.001). The sensitivity for the ABC score and DV were good and similar across shifts, but specificity was reduced using DV (DV mean 39%; ABC 98%).

CONCLUSIONS

PEF responses between work and rest show small differences according to shift type. The ABC score has a high sensitivity and specificity for all shifts; differences in DV have lower specificity.

Sensitization and irritant-induced occupational asthma with latency are clinically indistinguishable

BACKGROUND

Acute irritant exposures at work are well-recognized causes of asthma. In the occupational setting, low-dose exposure to the same agent does not provoke asthma. Occupational asthma (OA) with latency due to irritants is not widely accepted.

AIMS

To compare workers with OA with latency likely to be due to irritant exposures with workers with the more usual sensitization-induced OA.

METHODS

Following identification of a worker who fulfils all the criteria for irritant-induced OA with latency whose investigation documented lime dust as a cause for his OA, we searched the Shield reporting scheme database between 1989 and 2010 for entries where the OA was more likely to be due to irritant than allergic mechanisms and compared these with the remainder where allergic mechanisms were likely. Outcome measures were latent interval from first exposure to first work-related symptom, non-specific bronchial reactivity, smoking, atopy and the presence of pre-existing asthma.

RESULTS

A previously fit lecturer teaching bricklaying had irritant-induced OA with latency without unusual exposures with an immediate asthmatic reaction following exposure to a sand/lime mixture (pH 8). The Shield database identified 127 workers with likely irritant-induced asthma with latency and 1646 with hypersensitivity-induced OA. The two groups were indistinguishable in terms of pre-existing asthma, atopy, age, latent interval, non-specific reactivity and smoking.

CONCLUSIONS

Irritant exposure is a cause of OA with latency currently clinically indistinguishable from OA due to sensitization.

Occupational asthma caused by heated triglycidyl isocyanurate

Six workers exposed as bystanders to heated triglycidyl isocyanurate (TGIC) developed occupational asthma confirmed by serial peak expiratory flow measurement and Oasys analysis. Specific inhalation challenge testing resulted in late or dual asthmatic reactions to heated TGIC in four of four tested and was negative in three control asthmatics. One worker tested only with unheated TGIC had a negative specific challenge test. Heated TGIC can cause occupational asthma from bystander exposure.

Diagnosis of occupational asthma from time point differences in serial PEF measurements

BACKGROUND

The diagnosis of occupational asthma requires objective confirmation. Analysis of serial measurements of peak expiratory flow (PEF) is usually the most convenient first step in the diagnostic process. A new method of analysis originally developed to detect late asthmatic reactions following specific inhalation testing is described. This was applied to serial PEF measurements made over many days in the workplace to supplement existing methods of PEF analysis.

METHODS

236 records from workers with independently diagnosed occupational asthma and 320 records from controls with asthma were available. The pooled standard deviation for rest day measurements was obtained from an analysis of variance by time. Work day PEF measurements were meaned into matching 2-hourly time segments. Time points with mean work day PEF statistically lower (at the Bonferroni adjusted 5% level) than the rest days were counted after adjusting for the number of contributing measurements.

RESULTS

A minimum of four time point comparisons were needed. Records with >or=2 time points significantly lower on work days had a sensitivity of 67% and a specificity of 99% for the diagnosis of occupational asthma against independent diagnoses. Reducing the requirements to >or=1 non-waking time point difference increased sensitivity to 77% and reduced specificity to 93%. The analysis was only applicable to 43% of available records, mainly due to differences in waking times on work and rest days.

CONCLUSION

Time point analysis complements other validated methods of PEF analysis for the diagnosis of occupational asthma. It requires shorter records than are required for the Oasys score and can identify smaller changes than other methods, but is dependent on low rest day PEF variance.

Serial PEF measurement is superior to cross-shift change in diagnosing occupational asthma

Cross-shift measurements of peak expiratory flow (PEF) are commonly employed in the diagnosis of occupational asthma, although evidence for this approach is lacking. The current paper presents an evaluation of the technique. Mean changes in PEF across morning/day shifts were compared between workers with occupational asthma, confirmed using specific challenge testing, and non-working asthmatics. Individuals were divided into a development set, used to identify the optimum cross-shift change for diagnosing occupational asthma, and an evaluation set, used to test the sensitivity and specificity of this value. Comparative analysis of serial PEF records was performed using the Oasys-2 computerised system. A cross-shift decrease in PEF of 5 L.min(-1) achieved acceptable specificity in the development set. Applied to the evaluation set, this cut-off had a specificity of 90.9% and a sensitivity of 50%. Sensitivity could not be improved without unacceptable compromise to specificity. Analysis of serial PEF records using linear discriminant analysis identified occupational asthma with a sensitivity of 83.3% and a specificity of 90.9%. Serial analysis using mean work/rest day PEF comparison had a sensitivity of 66.7% and a specificity of 100%. Cross-shift changes in PEF in morning/day-shift workers have poor sensitivity in diagnosing occupational asthma, and are inferior to serial techniques.

Fifteen-year trends in occupational asthma: data from the Shield surveillance scheme

BACKGROUND

Trends of occupational asthma (OA) differ between regions depending on local industries, provisions for health and safety at the workplace and the availability of a reporting scheme to help in data collection and interpretation.

AIM

To assess trends in OA in an industrialized part of the UK over a 15-year period.

METHODS

Occupational and chest physicians in the West Midlands were invited to submit details of newly diagnosed cases with OA. Data were then transferred to the regional centre for occupational lung diseases for analysis.

RESULTS

A total of 1461 cases were reported to the scheme. Sixty-eight per cent were males with mean (standard deviation) age of 44 (12) years. The annual incidence of OA was 42 per million of working population (95% CI = 37-45). OA was most frequently reported in welders (9%) and health care-related professions (9%) while < 1% of cases were reported in farmers. Isocyanates were the commonest offending agents responsible for 21% of reports followed by metal working fluids (MWFs) (11%), adhesives (7%), chrome (7%), latex (6%) and glutaraldehyde (6%). Flour was suspected in 5% of cases while laboratory animals only in 1%.

CONCLUSIONS

Our data confirm a high annual incidence of OA in this part of the UK. MWFs are an emerging problem, while isocyanates remain the commonest cause. Incidence remained at a fairly stable background level with many small and a few large epidemics superimposed. Schemes like Midland Thoracic Society's Rare Respiratory Disease Registry Surveillance Scheme of Occupational Asthma could help in identifying outbreaks by linking cases at the workplace.

Clinical investigation of an outbreak of alveolitis and asthma in a car engine manufacturing plant

BACKGROUND

Exposure to metal working fluid (MWF) has been associated with outbreaks of extrinsic allergic alveolitis (EAA) in the USA, with bacterial contamination of MWF being a possible cause, but is uncommon in the UK. Twelve workers developed EAA in a car engine manufacturing plant in the UK, presenting clinically between December 2003 and May 2004. This paper reports the subsequent epidemiological investigation of the whole workforce. The study had three aims: (1) to measure the extent of the outbreak by identifying other workers who may have developed EAA or other work-related respiratory diseases; (2) to provide case detection so that those affected could be treated; and (3) to provide epidemiological data to identify the cause of the outbreak.

METHODS

The outbreak was investigated in a three-phase cross-sectional survey of the workforce. In phase I a respiratory screening questionnaire was completed by 808/836 workers (96.7%) in May 2004. In phase II 481 employees with at least one respiratory symptom on screening and 50 asymptomatic controls were invited for investigation at the factory in June 2004. This included a questionnaire, spirometry and clinical opinion. 454/481 (94.4%) responded and 48/50 (96%) controls. Workers were identified who needed further investigation and serial measurements of peak expiratory flow (PEF). In phase III 162 employees were seen at the Birmingham Occupational Lung Disease clinic. 198 employees returned PEF records, including 141 of the 162 who attended for clinical investigation. Case definitions for diagnoses were agreed.

RESULTS

87 workers (10.4% of the workforce) met case definitions for occupational lung disease, comprising EAA (n = 19), occupational asthma (n = 74) and humidifier fever (n = 7). 12 workers had more than one diagnosis. The peak onset of work-related breathlessness was Spring 2003. The proportion of workers affected was higher for those using MWF from a large sump (27.3%) than for those working all over the manufacturing area (7.9%) (OR = 4.39, p<0.001). Two workers had positive specific provocation tests to the used but not the unused MWF solution.

CONCLUSIONS

Extensive investigation of the outbreak of EAA detected a large number of affected workers, not only with EAA but also occupational asthma. This is the largest reported outbreak in Europe. Mist from used MWF is the likely cause. In workplaces using MWF there is a need to carry out risk assessments, to monitor and maintain fluid quality, to control mist and to carry out respiratory health surveillance.

Acute effects of atypical antipsychotics on whole-body insulin resistance in rats: implications for adverse metabolic effects

Although it is generally accepted that atypical antipsychotics differ in their risk for diabetic side effects, the underlying pharmacological mechanisms are unknown. Studies on the mechanisms of antipsychotic-induced hyperglycemia or insulin resistance are often confounded by the concomitant weight gain and dyslipidemia, known diabetic risk factors. To investigate whether antipsychotics can acutely cause metabolic effects before any change in body composition, we studied the effects of four atypical antipsychotics on whole-body insulin resistance. Using the hyperinsulinemic, euglycemic clamp technique in conscious rats, insulin and somatostatin were infused at a constant rate to provide constant hyperinsulinemia and to suppress pancreatic insulin secretion. Glucose was infused at a variable rate, adjusted to maintain euglycemia. At steady state, animals were administered vehicle (V) or antipsychotic and the glucose infusion rate was monitored as an index of insulin sensitivity. Clamp experiments using radiotracers and studies on glucose uptake into isolated skeletal muscle were conducted to differentiate between effects on hepatic glucose production (HGP) and on peripheral glucose uptake. Olanzapine (OLAN) and clozapine (CLOZ) acutely impaired whole-body insulin sensitivity in a dose-dependent manner (P<0.001 vs V), whereas ziprasidone and risperidone had no effect. CLOZ also induced profound insulin resistance after dosing 10 mg/kg/day for 5 days (P<0.05 vs V). Tracer studies indicated that acute changes mainly reflect increased HGP, consistent with the lack of effect on glucose uptake. OLAN and CLOZ can thus rapidly induce marked insulin resistance, which could contribute to the hyperglycemia and ketoacidosis reported for patients receiving those therapies.

Validation of parent self reported home safety practices

OBJECTIVES

To evaluate the validity of parents' self reported home safety practices concerning smoke detectors, bike helmets, car seats, and water heater temperature.

SETTING

Parents of children 12 years old and under whose child had made at least one visit to a study clinic in the years 2000-2003.

METHODS

As part of a randomized controlled trial to improve patient provider communication and preventive practices, parents' responses to telephone interview were compared with observations of safety practices during a home visit. Home visits were completed within nine weeks of the telephone interview. Parents were not told that the visit was part of a validation study and home visit observers were unaware of the interview responses. The authors calculated sensitivities, specificities, positive and negative predictive values, and their corresponding confidence intervals.

RESULTS

Sensitivity (0.78 to 0.98) and positive predictive values (0.75 to 1.00) were high for all items. Specificities and negative predictive values were more variable and the highest estimates (specificity 0.95 to 1.00, negative predictive value 0.95 to 0.97) were for car seat types.

CONCLUSIONS

The results suggest that parent self report practice of certain injury prevention behaviors (owning a car seat, hot water temperatures) is reliable, whereas self reports on other practices (working smoke detectors, properly fitting bike helmets) may be overstated.

Molecular mousetraps and the serpinopathies1

Members of the serine proteinase inhibitor or serpin superfamily inhibit their target proteinases by a remarkable conformational transition that involves the enzyme being translocated more than 70 Å (1 Å=10−10 m) from the upper to the lower pole of the inhibitor. This elegant mechanism is subverted by point mutations to form ordered polymers that are retained within the endoplasmic reticulum of secretory cells. The accumulation of polymers underlies the retention of mutants of α1-antitrypsin and neuroserpin within hepatocytes and neurons to cause cirrhosis and dementia respectively. The formation of polymers results in the failure to secrete mutants of other members of the serpin superfamily: antithrombin, C1 inhibitor and α1-antichymotrypsin, to cause a plasma deficiency that results in the clinical syndromes of thrombosis, angio-oedema and emphysema respectively. Understanding the common mechanism underlying the retention and deficiency of mutants of the serpins has allowed us to group these conditions as the serpinopathies. We review in this paper the molecular and structural basis of the serpinopathies and show how this has allowed the development of specific agents to block the polymerization that underlies disease.

The role of melanocortin-3 and -4 receptor in regulating appetite, energy homeostasis and neuroendocrine function in the pig

A recently discovered class of receptors, melanocortin-3 and -4 receptor (MC3/4-R), are located within the brain and modulate feed intake in rodents. Stimulation of the receptor (agonist) inhibits feed intake whereas blockade (antagonist) of the receptor increases intake. Our knowledge of factors regulating voluntary feed intake in humans and domestic animals is very limited. i.c.v. administration of an MC3/4-R agonist, NDP-MSH, suppressed (P<0.05) feed intake compared with controls at 12, 24, 48 and 72 h after treatment in growing pigs. Fed pigs were more responsive to the MC3/4-R agonist then fasted animals. However, i.c.v. treatment with MC3/4-R antagonist, SHU9119, failed to stimulate intake. The failure of MC3/4-R antagonist to stimulate feed intake suggests involvement of other brain hormone(s) which antagonize the action of SHU9119 at the MC3/4-R, blocking its stimulatory effect on intake. Treatment with NDP-MSH or SHU9119, across a wide dose range, failed to affect LH and GH secretion, except for the 10 micro g dose of NDP-MSH, which exhibited both a stimulatory and an inhibitory effect on GH secretion in fasted animals. Treatment with agouti-related peptide, a natural brain hormone that blocks the MC3/4R, failed to stimulate feed intake. These results do not support the idea that endogenous melanocortin pays a critical role in regulating feed intake and pituitary hormone secretion in the pig. SHU9119 blocked the NDP-MSH-induced increase in cAMP in HEK293 cells expressing the porcine MC4-R sequence without the missense mutation. The EC(50) and IC(50) values were similar to the human MC4-R, confirming that SHU9119 is a pig MC4-R antagonist. However, pigs were heterozygous for an MC4-R gene missense mutation. It is possible that the MC4-R mutation alters function and this may explain the failure to demonstrate MC3/4-R involvement in modulating feeding behavior and LH and GH secretion in the pig.

Occupational asthma due to low molecular weight agents: eosinophilic and non-eosinophilic variants

BACKGROUND

Despite having a work related deterioration in peak expiratory flow (PEF), many workers with occupational asthma show a low degree of within day diurnal variability atypical of non-occupational asthma. It was hypothesised that these workers would have a neutrophilic rather than an eosinophilic airway inflammatory response.

METHODS

Thirty eight consecutive workers with occupational asthma induced by low molecular weight agents underwent sputum induction and assessment of airway physiology while still exposed at work.

RESULTS

Only 14 (36.8%) of the 38 workers had sputum eosinophilia (>2.2%). Both eosinophilic and non-eosinophilic groups had sputum neutrophilia (mean (SD) 59.5 (19.6)% and 55.1 (18.8)%, respectively). The diurnal variation and magnitude of fall in PEF during work periods was not significantly different between workers with and without sputum eosinophilia. Those with eosinophilia had a lower forced expiratory volume in 1 second (FEV1; 61.4% v 83% predicted, mean difference 21.6, 95% confidence interval (CI) 9.2 to 34.1, p=0.001) and greater methacholine reactivity (geometric mean PD20 253 microg v 1401 microg, p=0.007). They also had greater bronchodilator reversibility (397 ml v 161 ml, mean difference 236, 95% CI of difference 84 to 389, p=0.003) which was unrelated to differences in baseline FEV(1). The presence of sputum eosinophilia did not relate to the causative agent, duration of exposure, atopy, or lack of treatment.

CONCLUSIONS

Asthma caused by low molecular weight agents can be separated into eosinophilic and non-eosinophilic pathophysiological variants with the latter predominating. Both groups had evidence of sputum neutrophilia. Sputum eosinophilia was associated with more severe disease and greater bronchodilator reversibility but no difference in PEF response to work exposure.

Alcohol consumption increases the risk of fatal breast cancer (United States)

OBJECTIVE

To investigate the hypothesis that alcohol consumption increases the risk of breast cancer mortality.

METHODS

We examined breast cancer mortality in relation to self-reported alcohol consumption in women from the American Cancer Society Cancer Prevention Study (CPS)-II. After 14 years of follow-up, 1,442 eligible breast cancer deaths were observed among 242,010 women. Cox proportional hazards models were constructed for total alcohol consumption and for beer, wine, and liquor separately.

RESULTS

Total alcohol consumption was associated with increased risk of fatal breast cancer among post- but not pre- or perimenopausal women. Even less than one drink/day was associated with up to a 30% increase in breast cancer mortality among postmenopausal women compared to non-drinkers (RR = 1.3, 95% CI: 1.1-1.6 for women drinking 0.26-<1 drink/day). When examined separately, consumption of beer, wine, and liquor each increased the risk of breast cancer among postmenopausal women. We found no evidence that alcohol consumption was more deleterious among women at high risk for breast cancer compared to average-risk women.

CONCLUSION

This study adds to the evidence that postmenopausal women can reduce their risk of breast cancer by avoiding or minimizing their use of alcohol.

A prospective study of diet and stomach cancer mortality in United States men and women

Frequent consumption of fruits, vegetables, and whole grains has been associated with a reduced risk of stomach cancer in the majority of case-control studies of these factors: however, prospective studies have been less consistent. We examined the association between selected major food groups (citrus fruits, vegetables, whole grains, and processed meats) and risk of fatal stomach cancer in the Cancer Prevention Study (CPS) II cohort of 1.2 million United States men and women. During 14 years of follow-up, we documented 439 stomach cancer deaths in women and 910 in men after exclusion of individuals with prevalent cancers, inadequate diet information, and recent weight loss at baseline in 1982. After controlling for other risk factors, none of the food groups examined were associated with risk of stomach cancer except for an unexpected increased risk with vegetable consumption in women [relative risk (RR) = 1.25; 95% confidence interval (CI), 0.99-1.58; highest versus lowest tertile, P = 0.06 for trend]. A high overall plant food intake (a sum of vegetables, citrus fruit, and whole grains) was associated with reduced risk in men (RR = 0.79; 95% CI, 0.67-0.93; highest versus lowest tertile, P = 0.003 for trend), but not in women (RR = 1.18; 95% CI, 0.93-1.50; P = 0.16 for trend). Of individual foods examined, liver consumption greater than twice/week was associated with an increased risk of fatal stomach cancer in women (RR = 1.96; 95% CI, 1.09-3.53) and men (RR = 1.63; 95% CI, 1.02-2.62) compared with nonconsumers. This study supports a modest role for plant foods in reducing the risk of fatal stomach cancer in men, but not in women.

Small molecule somatostatin receptor subtype-2 antagonists

The first potent small molecule sst2 antagonists are reported. Altering known sst2 agonist molecules yielded compounds with high sst2 binding affinity and full antagonist activity. Compound 7a, for example, displaced somatostatin binding to the sst2 receptor with an IC(50)=2.9 nM and antagonized somatostatin action with an IC(50)=29nM.

Determinants of DNA yield and quality from buccal cell samples collected with mouthwash

Buccal cells are becoming an important source of genomic DNA in epidemiological studies, but little is known about the effect of different sampling conditions on DNA quality and yield. We used a mouthwash protocol to collect six daily buccal cell samples from 35 healthy volunteers. Twenty-four individuals (six men and 18 women) correctly completed the protocol and were included in paired analyses to determine whether "swish" time (30 s versus 60 s), toothbrushing before collection, or lag time between collection and DNA extraction (1 day versus 5, 10, or 30 days at room temperature) would affect sample quality and yield. Total DNA, human-specific DNA (hDNA), degradation of DNA, and ability to amplify by PCR were determined. hDNA yield did not significantly vary by "swish" time. However, toothbrushing 1 h before sample collection reduced the amount of hDNA by nearly 40% (34 microg versus 21 microg; P = 0.06). Median hDNA yields for samples that were held for 1, 5, 10, and 30 days before extraction were 32 microg (range, 4-196), 32 microg (2-194), 23 microg (3-80), and 21 microg (5-56), respectively. The 10- and 30-day samples had significantly less hDNA than those processed after 1 day (P = 0.01). PCR success rates for beta-globin gene fragments of length 268 bp, 536 bp, and 989 bp were 94% or better, and high molecular weight DNA (>23 kb) was found in all but one sample. These results suggest that buccal cells should be collected before brushing teeth and processed within 5 days of collection to maximize hDNA yield.

Spongiform leucoencephalopathy following intravenous heroin abuse: radiological and histopathological findings

A case of spongiform leucoencephalopathy in a known intravenous heroin abuser is presented. To our knowledge, this is the only case of heroin-related spongiform leucoencephalopathy reported in Australia. The relationship to intravenous rather than inhaled heroin is particularly unusual with only one other possible case documented in the literature. The imaging and histopathological findings are described.

Can selection assessments predict students' achievements in the premedical year?: a study at Arabian Gulf University

BACKGROUND

In a problem-based learning (PBL) program, students are encouraged to develop self-motivation, self-confidence, communication skills and problem-solving skills. Measuring these attributes when selecting students into medical schools is a formidable task. Admission to medical school typically depends upon students' academic achievement in their prior education. In the past 3 years the College of Medicine and Medical Science (CMMS) at the Arabian Gulf University, which has a PBL curriculum, adopted an admission policy that utilizes final high school scores, a written admission examination in English and science, as well as a structured interview.

OBJECTIVE

To determine the extent to which the admissions measures predict academic achievement in the first year of studies at CMMS.

DESIGN

Prediction study of prospectively collected data. Final cumulative score for all subjects at the end of the first year was the main dependent variable analyzed.

SUBJECTS

All students admitted to the college during the academic year 1998-1999.

RESULTS

The written admission science examination scores had the highest correlation (r =0.663, p< 0.05) with the Year 1 final cumulative score. Although the admission interview focused on non-cognitive student attributes, which may or may not affect the students' academic performance, its score had a statistically significant, if low, correlation with the Year 1 final cumulative score (r =0.275, p< 0.012). Approximately 59% of the total variability of the Year 1 final cumulative scores could be explained by the admission examination scores in science and English and the high school scores.

CONCLUSION

Procedures for selecting students who are most likely to succeed academically in the initial year at an innovative medical school deserve further study and probably should include both academic performance and non-academic attributes.

Hereditary haemorrhagic telangiectasia simulating biliary tree obstruction secondary to malignant porta hepatis lymphadenopathy

Hereditary telangiectasis is an uncommon condition and is thus not usually considered in the differential diagnosis of porta hepatis lymphadenopathy causing biliary tree obstruction. The present case illustrates a patient in whom tortuous vessels in the porta hepatis simulated masses on delayed contrast-enhanced CT with subsequent referral for biopsy.

Behaviour of the human bladder during natural filling: the Newcastle experience of ambulatory monitoring and conventional artificial filling cystometry

Conventional Artificial Filling Cystometry (CMG) is the Gold Standard investigation of detrusor function although the findings are limited by the constraints of rapid rates of filling with artificial filling media in conditions of restricted mobility and the clinical environment. Recent advances in technology have allowed the use of ambulatory monitoring (AM) of detrusor function during which the bladder fills at natural rates with urine whilst the patient is able to exercise and perform normal daily activities outside the clinical environment. Comparative studies of CMG and AM in the Department of Urology at the Freeman Hospital, Newcastle-upon-Tyne in recent years have shown interesting differences in the results obtained between the techniques. During AM the bladder pressure rise on filling is seen to be lower and associated with a greater incidence of spontaneous phasic detrusor activity than during CMG, whilst detrusor contraction pressures during the voiding phase following natural filling, are generally seen to be higher than during CMG. Several groups of patients, including men with neuropathic bladder disorder, chronic retention of urine and bladder outflow obstruction together with a group of asymptomatic healthy volunteers have been studied and the results presented.

Occupational asthma due to chrome and nickel electroplating

BACKGROUND

Exposure to chromium during electroplating is a recognised though poorly characterised cause of occupational asthma. The first series of such patients referred to a specialist occupational lung disease clinic is reported.

METHODS

The diagnosis of occupational asthma was made from a history of asthma with rest day improvement and confirmed by specific bronchial provocation testing with potassium dichromate and nickel chloride.

RESULTS

Seven workers had been exposed to chrome and nickel fumes from electroplating for eight months to six years before asthma developed. One subject, although exposed for 11 years without symptoms, developed asthma after a single severe exposure during a ventilation failure. This was the only subject who had never smoked. The diagnosis was confirmed by specific bronchial challenges. Two workers had isolated immediate reactions, one a late asthmatic reaction, and four a dual response following exposure to nebulised potassium dichromate at 1-10 mg/ml. Two of the four subjects were also challenged with nebulised nickel chloride at 0.1-10 mg/ml. Two showed isolated late asthmatic reactions, in one at 0.1 mg/ml, where nickel was probably the primary sensitising agent. Four workers carried out two hourly measurements of peak expiratory flow over days at and away from work. All were scored as having occupational asthma using OASYS-2. Breathing zone air monitoring was carried out in 60 workers from four decorative and two hard chrome plating shops from workers with similar jobs to those sensitised. No measurement exceeded the current occupational exposure standard for chromate or nickel, the mean levels of chromate exposure for jobs similar to those of the affected workers were 9-15 micrograms/m3.

CONCLUSION

Chrome used in electroplating is a potential cause of occupational asthma. Sensitivity to chrome in electroplaters may occur in situations where exposure levels are likely to be within the current exposure standards. There may be cross reactivity with nickel. Inhalation challenge with nebulised potassium dichromate solution is helpful in making the specific diagnosis where doubt exists.

Conventional urodynamics and ambulatory monitoring in the definition and management of bladder outflow obstruction

PURPOSE

We determined whether ambulatory urodynamics and new objective methods of defining bladder outflow obstruction might improve the classification of bladder outflow obstruction over conventional urodynamics (cystometrography), and whether such measures might improve prediction of the outcome of prostatectomy.

MATERIALS AND METHODS

A prospective study was performed of 122 men undergoing prostatectomy for symptoms and low flow rates. Cystometrography and ambulatory urodynamics were performed before and 6 months after prostatectomy but did not influence selection for operation. Methods of classifying obstruction included the Abrams-Griffiths nomogram, Schäfer linear passive urethral resistance relation and Griffiths urethral resistance factor.

RESULTS

The proportion of cases defined as obstructed did not differ on ambulatory urodynamics or cystometrography or when the Abrams-Griffiths nomogram was compared to the linear passive urethral resistance relation or urethral resistance factor. Significant improvements after prostatectomy were noted in flow rates (p < 0.001), residual urine (p < 0.001), voiding pressure (p < 0.001) and symptom scores (p < 0.001). Ambulatory urodynamics were more sensitive than cystometrography in detection of detrusor instability but detrusor instability did not correlate with outcome. Voiding pressures were greater during ambulatory urodynamics (p < 0.02). The outcome of obstructed cases (on Abrams-Griffiths nomogram during ambulatory urodynamics) was better (79% good outcome) than that of nonobstructed or equivocally obstructed cases (55% good symptomatic outcome, p < 0.05).

CONCLUSIONS

Men proved to have obstruction on the basis of pressure and flow measurements applied to a nomogram have better outcomes after transurethral resection of the prostate but sophisticated or computer derived methods of classification of obstruction did not improve prediction.

Bladder function in healthy volunteers: ambulatory monitoring and conventional urodynamic studies

OBJECTIVE

To obtain data on conventional artificial filling cystometry and ambulatory monitoring in healthy asymptomatic control populations.

SUBJECTS AND METHODS

Seventeen healthy volunteers were assessed by means of artificial filling cystometry (CMG), filling at rates of 50 ml/min (CMG 50) and 100 ml/min (CMG 100), and ambulatory monitoring (AM).

RESULTS

Significant differences were found between AM and CMG with respect to: the pressure rise on filling (P < 0.02), voided volumes (P < 0.01) and maximum detrusor pressure on micturition (P < 0.01). Detrusor instability was found in 38% of volunteers on AM, in 17% on CMG 50, but in none on CMG 100.

CONCLUSION

A range of baseline urodynamic values has been established which could provide the basis for future studies of ambulatory monitoring.

Health, employment, and financial outcomes in workers with occupational asthma

OBJECTIVE

To study the health, employment, and financial outcome of occupational asthma.

DESIGN

A follow study of workers with confirmed occupational asthma.

SETTING

A specialist occupational lung disease clinic.

SUBJECTS

All workers had a diagnosis of occupational asthma made at least one year earlier. Diagnosis was confirmed by serial peak expiratory flow measurement, specific bronchial provocation testing, or specific immunology.

MAIN OUTCOME MEASURES

Respiratory symptoms, medication, pulmonary function, employment state, and financial position.

RESULTS

112 of a total of 140 eligible workers were followed up. 32% of patients remained exposed to the causative agent. These workers had more symptoms at follow up than those removed and a greater number were taking inhaled steroids. Continued exposure was also associated with a fall in % predicted forced expiratory volume in one second (FEV1) of 3% compared with that at presentation. Their median loss of annual income due to occupational asthma was 35%. Those removed from exposure were worse off financially (median loss 54% of annual income), had fewer respiratory symptoms than the group who remained exposed, and their % predicted FEV1 had improved by 4.6%. Statutory compensation and that obtained by common law suits did not match the loss of earnings due to the development of occupational asthma. Of the workers removed from exposure, those who no longer complained of breathlessness had been diagnosed significantly earlier after the onset of their first symptom (48 v 66 months, p = 0.001) and had a significantly higher FEV1 at presentation (90% v 73% predicted, p = 0.008) compared with those who were still breathless. They had developed symptoms earlier after first exposure (48 v 66 months, p > 0.05) and had been removed from exposure sooner (eight v 12 months, p > 0.05).

CONCLUSION

Removal from exposure after diagnosis of occupational asthma is beneficial in terms of symptoms and lung function, but is associated with a loss of income. Early diagnosis is important for symptomatic improvement after removal from exposure. Inadequate compensation may contribute to the workers' decision to remain exposed after diagnosis.

Bladder augmentation and replacement. Urodynamic and clinical review of 25 patients

Bladder augmentation has a role in the management of patients with neuropathic bladder dysfunction and in urinary undiversion. Several reports attest to its clinical value, but there have been few detailed urodynamic studies of its effects. We have carried out a prospective review over a 4-year period of 25 patients undergoing bladder augmentation or substitution assessed by conventional and ambulatory urodynamic studies. All patients had a detubularised reservoir made of ileum in 6, and of the ileocaecal segment in the remainder. Six patients also had an artificial sphincter fitted and 2 underwent colposuspension. There was no mortality. After operation, bladder capacity increased from 122 +/- 91 ml to 659 +/- 431 ml and there were significant decreases in the pressure rise during filling and increases in bladder compliance. Hyper-reflexia was present in 74% before operation and 23% after operation. Regular phasic activity was observed in 77% of patients at the end of filling after operation, probably due to bowel activity despite detubularisation. Four patients described urge incontinence associated with this activity. After operation, one man had persistent major stress incontinence. He has since undergone insertion of an artificial urinary sphincter (AUS) and is now completely dry. Of the remainder, 10 patients had minor, infrequent defects in continence, 9 patients with leakage when the bladder was full and 4 with occasional leakage at night. With the exception of the patient with major stress incontinence, all but one felt the operation had been worthwhile--40% reporting complete success and 52% excellent improvement. Reconstruction of the neuropathic lower urinary tract is a major surgical procedure, but the final clinical outcome is very satisfactory.

Response to corticosteroids in chronic airflow obstruction: relationship to emphysema and airways collapse

We have studied the relationship between emphysema and airways collapse, and response to corticosteroids in patients with chronic airflow obstruction. One hundred and seven patients completed a placebo-controlled trial comparing 2 wks treatment with oral prednisolone 40 mg.day-1 to inhaled beclomethasone dipropionate 500 micrograms t.d.s. Response to corticosteroids was defined on the basis of changes in forced expiratory volume in one second (FEV1), and/or forced vital capacity (FVC), and/or mean peak expiratory flow (PEF) after treatment. Patients were categorized as those with physiologically defined emphysema (carbon monoxide transfer coefficient (KCO) less than 70% predicted and total lung capacity greater than 120% predicted), and those with pressure dependent airways collapse on the flow-volume loop (ratio of inspiratory to expiratory flow at 50% vital capacity [I:E50] greater than 10). The response to placebo showed a significant order effect, probably due to a carry-over effect of active treatment of at least 3 wks. Hence, the efficacy of active treatment over placebo in the subgroups defined was assessed by analysis of data generated from the first treatment phase of the trial. The presence or absence of physiologically defined emphysema did not affect the response to oral prednisolone. Inhaled beclomethasone dipropionate, however, was less effective in the emphysema group. Pressure dependent airways collapse did not affect the response to either prednisolone or beclomethasone. However, when data from all three treatment phases were analysed there was no significant difference in the response to either drug in any of the subgroups defined.(ABSTRACT TRUNCATED AT 250 WORDS)

Response to corticosteroids in chronic airflow obstruction: relationship to emphysema and airways collapse

We have studied the relationship between emphysema and airways collapse, and response to corticosteroids in patients with chronic airflow obstruction. One hundred and seven patients completed a placebo-controlled trial comparing 2 wks treatment with oral prednisolone 40 mg.day-1 to inhaled beclomethasone dipropionate 500 micrograms t.d.s. Response to corticosteroids was defined on the basis of changes in forced expiratory volume in one second (FEV1), and/or forced vital capacity (FVC), and/or mean peak expiratory flow (PEF) after treatment. Patients were categorized as those with physiologically defined emphysema (carbon monoxide transfer coefficient (KCO) less than 70% predicted and total lung capacity greater than 120% predicted), and those with pressure dependent airways collapse on the flow-volume loop (ratio of inspiratory to expiratory flow at 50% vital capacity [I:E50] greater than 10). The response to placebo showed a significant order effect, probably due to a carry-over effect of active treatment of at least 3 wks. Hence, the efficacy of active treatment over placebo in the subgroups defined was assessed by analysis of data generated from the first treatment phase of the trial. The presence or absence of physiologically defined emphysema did not affect the response to oral prednisolone. Inhaled beclomethasone dipropionate, however, was less effective in the emphysema group. Pressure dependent airways collapse did not affect the response to either prednisolone or beclomethasone. However, when data from all three treatment phases were analysed there was no significant difference in the response to either drug in any of the subgroups defined.(ABSTRACT TRUNCATED AT 250 WORDS)

Pseudoaneurysm of the internal carotid artery: a forgotten complication of tonsillitis?

Pseudoaneurysm of the internal carotid artery is an uncommon but potentially lethal complication of tonsillar or peritonsillar sepsis, which appears to have occurred more frequently prior to the introduction of penicillin. Management of such a case is discussed, and a literature review presented.

A familial interstitial deletion of the long arm of chromosome 21

A mother and daughter with an interstitial deletion of the chromosome segment 21q11 to 21q21.3 have similar minor dysmorphism and mild mental retardation. These two patients are compared to others in the literature with deletion of the same region of chromosome 21. Molecular analysis of DNA from our patients localizes the DNA segments D21S1, D21S11, D21S8, and D21S22 within the deleted region.

Corticosteroid trials in non-asthmatic chronic airflow obstruction: a comparison of oral prednisolone and inhaled beclomethasone dipropionate

One hundred and twenty seven adults considered on clinical grounds to have non-asthmatic chronic airflow obstruction entered a randomised, double blind, placebo controlled, crossover trial comparing the physiological response to inhaled beclomethasone dipropionate 500 micrograms thrice daily with oral prednisolone 40 mg a day, both given for two weeks. One hundred and seven patients completed the study. Response was assessed as change in FEV1 and FVC measured on the last treatment day, and as change in mean peak expiratory flow (PEF) over the final seven days of treatment from home PEF recordings performed five times daily. A full response to treatment was defined as an increase in FEV or FVC, or an increase in mean daily PEF over the final seven days of treatment, of at least 20% from baseline values. An improvement in one measurement of at least 15%, or of 10% in any two measurements, was defined as a partial treatment response. Response to placebo showed a significant order effect, suggesting a carry over effect of active treatment of at least three weeks. Response to active treatment was therefore related to initial baseline values, and compared with placebo by considering responses in the first treatment phase only. A full response to oral prednisolone (16/38) was significantly more common than to placebo (3/35). The number of full responses to inhaled beclomethasone (8/34) did not differ significantly from the number responding to oral prednisolone or placebo in the first treatment phase, though full and partial responses to inhaled beclomethasone (12/34) were significantly more common than those to placebo (4/35). When all three treatment phases were considered 44/107 patients showed a full response to one or both forms of corticosteroid treatment, a response to prednisolone (39) occurring more frequently than to inhaled beclomethasone (26). Only 21 of the 44 responders showed a response to both forms of treatment. Inhaled beclomethasone dipropionate 500 micrograms thrice daily was inferior to oral prednisolone 40 mg per day, but better than placebo, in producing improvement in physiological measurements in patients thought to have nonasthmatic chronic airflow obstruction. It was, however, an effective alternative in over half of those showing a response to prednisolone.