Diagnosis and management of work-related asthma: American College Of Chest Physicians Consensus Statement

BACKGROUND

A previous American College of Chest Physicians Consensus Statement on asthma in the workplace was published in 1995. The current Consensus Statement updates the previous one based on additional research that has been published since then, including findings relevant to preventive measures and work-exacerbated asthma (WEA).

METHODS

A panel of experts, including allergists, pulmonologists, and occupational medicine physicians, was convened to develop this Consensus Document on the diagnosis and management of work-related asthma (WRA), based in part on a systematic review, that was performed by the University of Alberta/Capital Health Evidence-Based Practice and was supplemented by additional published studies to 2007.

RESULTS

The Consensus Document defined WRA to include occupational asthma (ie, asthma induced by sensitizer or irritant work exposures) and WEA (ie, preexisting or concurrent asthma worsened by work factors). The Consensus Document focuses on the diagnosis and management of WRA (including diagnostic tests, and work and compensation issues), as well as preventive measures. WRA should be considered in all individuals with new-onset or worsening asthma, and a careful occupational history should be obtained. Diagnostic tests such as serial peak flow recordings, methacholine challenge tests, immunologic tests, and specific inhalation challenge tests (if available), can increase diagnostic certainty. Since the prognosis is better with early diagnosis and appropriate intervention, effective preventive measures for other workers with exposure should be addressed.

CONCLUSIONS

The substantial prevalence of WRA supports consideration of the diagnosis in all who present with new-onset or worsening asthma, followed by appropriate investigations and intervention including consideration of other exposed workers.

Symptoms of wheeze and persistent cough in the first year of life: associations with indoor allergens, air contaminants, and maternal history of asthma

In a cohort of 849 infants with an asthmatic sibling, the authors examined the relations of exposure to allergens (dust mite, cockroach, cat, and dog), nitrogen dioxide, and mold with symptoms of wheeze and persistent cough in the first year of life (1998-2000). Among infants whose mothers had physician-diagnosed asthma, neither dust mite allergen nor dog allergen was associated with either symptom. Exposure to cockroach allergen (Bla g 1 at >or=2 U/g) modestly increased the risk for wheeze (odds ratio (OR) = 1.87, 95% confidence interval (CI): 0.94, 3.71), and exposure to cat allergen modestly decreased the risk (OR = 0.60, 95% CI: 0.35, 1.03). Among infants of mothers with no asthma history, exposure to gas stoves (OR = 1.50, 95% CI: 1.05, 2.15) and wood-burning stoves (OR = 2.09, 95% CI: 1.12, 3.91) increased the risk of persistent cough. Similarly, measured nitrogen dioxide concentration was associated with persistent cough (OR = 1.21, 95% CI: 1.05, 1.40). Persistent mold affected both infants of mothers with asthma (for wheeze, OR = 2.27, 95% CI: 1.27, 4.07; for cough, OR = 1.83, 95% CI: 1.04, 3.22) and infants of mothers without asthma (for cough, OR = 1.55, 95% CI: 1.04, 2.31). Reported exposure was confirmed by an association of measured fungi with wheeze (OR = 1.23, 95% CI: 1.01, 1.49). This appears to have been the first study to measure all of these home exposures (indoor allergens, nitrogen dioxide, fungi) and to prospectively measure the frequency of infant wheeze and persistent cough.

Are ambient ultrafine, accumulation mode, and fine particles associated with adverse cardiac responses in patients undergoing cardiac rehabilitation?

BACKGROUND

Mechanisms underlying previously reported air pollution and cardiovascular (CV) morbidity associations remain poorly understood.

OBJECTIVES

We examined associations between markers of pathways thought to underlie these air pollution and CV associations and ambient particle concentrations in postinfarction patients.

METHODS

We studied 76 patients, from June 2006 to November 2009, who participated in a 10-week cardiac rehabilitation program following a recent (within 3 months) myocardial infarction or unstable angina. Ambient ultrafine particle (UFP; 10-100 nm), accumulation mode particle (AMP; 100-500 nm), and fine particle concentrations (PM2.5; ≤ 2.5 μm in aerodynamic diameter) were monitored continuously. Continuous Holter electrocardiogram (ECG) recordings were made before and during supervised, graded, twice weekly, exercise sessions. A venous blood sample was collected and blood pressure was measured before sessions.

RESULTS

Using mixed effects models, we observed adverse changes in rMSSD [square root of the mean of the sum of the squared differences between adjacent normal-to-normal (NN) intervals], SDNN (standard deviation of all NN beat intervals), TpTe (time from peak to end of T-wave), heart rate turbulence, systolic and diastolic blood pressures, C-reactive protein, and fibrinogen associated with interquartile range increases in UFP, AMP, and PM2.5 at 1 or more lag times within the previous 5 days. Exposures were not associated with MeanNN, heart-rate-corrected QT interval duration (QTc), deceleration capacity, and white blood cell count was not associated with UFP, AMP, and PM2.5 at any lag time.

CONCLUSIONS

In cardiac rehabilitation patients, particles were associated with subclinical decreases in parasympathetic modulation, prolongation of late repolarization duration, increased blood pressure, and systemic inflammation. It is possible that such changes could increase the risk of CV events in this susceptible population.

Hypersensitivity pneumonitis associated with environmental mycobacteria

A previously healthy man working as a machine operator in an automotive factory developed respiratory symptoms. Medical evaluation showed abnormal pulmonary function tests, a lung biopsy showed hypersensitivity pneumonitis, and his illness was traced to his work environment. His physician asked the employer to remove him from exposure to metalworking fluids. Symptoms reoccurred when he was later reexposed to metalworking fluids, and further permanent decrement in his lung function occurred. Investigation of his workplace showed that five of six large reservoirs of metalworking fluids (cutting oils) grew Mycobacterium chelonae (or Mycobacterium immunogenum), an organism previously associated with outbreaks of hypersensitivity pneumonitis in automaking factories. His lung function remained stable after complete removal from exposure. The employer, metalworking fluid supplier, union, and the National Institute for Occupational Safety and Health were notified of this sentinel health event. No further cases have been documented in this workplace.

A role for transcription factor GTF2IRD2 in executive function in Williams-Beuren syndrome

Executive functions are amongst the most heritable cognitive traits with twin studies indicating a strong genetic origin. However genes associated with this domain are unknown. Our research into the neurodevelopmental disorder Williams-Beuren syndrome (WBS) has identified a gene within the causative recurrent 1.5/1.6 Mb heterozygous microdeletion on chromosome 7q11.23, which may be involved in executive functioning. Comparative genome array screening of 55 WBS patients revealed a larger ∼1.8 Mb microdeletion in 18% of cases, which results in the loss of an additional gene, the transcription factor GTF2IRD2. The GTF gene family of transcription factors (GTF2I, GTF2IRD1 and GTF2IRD2) are all highly expressed in the brain, and GTF2I and GTF2IRD1 are involved in the pathogenesis of the cognitive and behavioural phenotypes associated with WBS. A multi-level analysis of cognitive, behavioural and psychological functioning in WBS patients showed that those with slightly larger deletions encompassing GTF2IRD2 were significantly more cognitively impaired in the areas of spatial functioning, social reasoning, and cognitive flexibility (a form of executive functioning). They also displayed significantly more obsessions and externalizing behaviours, a likely manifestation of poor cognitive flexibility and executive dysfunction. We provide the first evidence for a role for GTF2IRD2 in higher-level (executive functioning) abilities and highlight the importance of integrating detailed molecular characterisation of patients with comprehensive neuropsychological profiling to uncover additional genotype-phenotype correlations. The identification of specific genes which contribute to executive function has important neuropsychological implications in the treatment of patients with conditions like WBS, and will allow further studies into their mechanism of action.

Infant respiratory symptoms associated with indoor heating sources

This study examined the effects of indoor heating sources on infant respiratory symptoms during the heating season of the first year of life. Mothers delivering babies between 1993 and 1996 at 12 hospitals in Connecticut and Virginia were enrolled. Daily symptom and heating source use information about their infant was obtained every 2 weeks during the first year of life. Heating sources included fireplace, wood stove, kerosene heater, and gas space heater use. Four health outcomes were analyzed by reporting period: days of wheeze, episodes of wheeze, days of cough, and episodes of cough. A large percentage of infants had at least one episode of cough (88%) and wheeze (33%) during the heating season of the first year of life. Wood stove, fireplace, kerosene heater, and gas space heater use was intermittent across the study period. In adjusted Poisson regression models controlling for important confounders, gas space heater use was associated with episodes and days of wheeze. Wood stove use was associated with total days of cough, and kerosene heater use was associated with episodes of cough. Fireplace use was not associated with any of the respiratory symptoms. Use of some heating sources appears related to respiratory symptoms in infants.

Shock, adjust, decide: reproductive decision making in cystic fibrosis (CF) carrier couples--a qualitative study

Cystic fibrosis (CF) is the most common recessive condition affecting the White British population. Facilitating reproductive decision making for couples at genetic risk for CF is an important aspect of genetic counseling practice in the UK. The purpose of this study was to explore the reproductive decision making process for 31 members of CF carrier couples (15 men and 16 women) with or without an affected child. The design involved a qualitative approach consisting of semi-structured interviews and data analysis informed by grounded theory methodology. Sex and personal experience of CF were identified as factors that may influence reproductive decision making. Findings suggest these hypotheses: (1) CF carrier couples who have an affected child/pregnancy, are more likely to embark on another pregnancy than couples who have a healthy child from an at-risk pregnancy, and (2) men and women play different roles in the reproductive decision making process. Data analysis resulted in development of a structured framework modeling the reproductive decision making process, which may be helpful in guiding genetic counseling with CF carrier couples and other at risk couples making reproductive decisions.

Hard metal interstitial pulmonary disease associated with a form of welding in a metal parts coating plant

We describe two cases of hard metal pulmonary disease (one fatal) in workers employed in the same area of a metal coating plant using the detonation gun process for applying a durable metal surface to metal parts. In this form of welding, a mixture of powdered metals, including tungsten carbide and cobalt, is heated by ignition of a flammable gas and propelled from the end of the "gun" at high temperature and velocity to form a welded metal coating. This process is done in an enclosed chamber and with each application, large volumes of fine aerosols are created. Inhalation exposure to hard metal may occur during the mounting and removal of the metal parts between applications, in spite of engineering controls and industrial hygiene surveillance. One of the cases presented with minimal chest x-ray abnormalities and an obstructive pattern on pulmonary function testing, although subsequent open lung biopsy showed diffuse interstitial pulmonary fibrosis. The fact that two cases of hard metal pulmonary interstitial disease occurred where thorough exposure control procedures and a surveillance program for cobalt were in place may indicate the need for revisions of the current technology used when hard metal is applied in the detonation gun process.

Increased cardiovascular risk associated with reduced kidney function

BACKGROUND

Individuals with chronic kidney disease (CKD) are at substantial risk for cardiovascular mortality, but the risk associated with specific glomerular filtration rates (GFRs) is unknown. The objective of this study was to investigate the relationship between level of kidney function and the risk of cardiovascular mortality in a diverse population.

METHODS AND RESULTS

This was a nonconcurrent cohort study of 34,982 ambulatory patients. Kidney function was entered into the model as a time-dependent variable to minimize misclassification and allow for improved estimate of the effect of decreasing GFR on cardiovascular mortality. The adjusted hazard ratio for cardiovascular mortality was 1.00 (95% CI 0.93-1.06) with an estimated GFR (eGFR) of 45-59; 1.77 (95% CI 1.65-1.89) with an eGFR 30-44; 3.75 (95% CI 3.47-4.06) with an eGFR 15-29, and 3.83 (95% CI 3.40-4.33) with an eGFR <15.

CONCLUSION

We demonstrate a graded risk of cardiovascular mortality with decreasing GFR, with a marked increase with an eGFR <45 ml/min/1.73 m(2). These data also suggest that the availability of eGFR to physicians has had little impact on reducing the cardiovascular risk facing individuals with CKD. Our findings further highlight the public health significance of CKD and the importance of its early identification and management to reduce cardiovascular mortality.

Acute Changes in Ambient Temperature Are Associated With Adverse Changes in Cardiac Rhythm

BACKGROUND

Both increases and decreases in ambient temperature have been associated with increased cardiovascular mortality and morbidity. However, the mechanism(s) remain unclear.

OBJECTIVES

We examined associations between biomarkers of pathways thought to, in part, explain these associations and changes in ambient temperature in a panel of predominantly post-myocardial infarction or post-stent patients.

METHODS

We studied 76 subjects who had a recent coronary event and were participating in a cardiac rehabilitation program. In these patients, we measured heart rate variability, repolarization, and baroreflex sensitivity parameters using Holter ECG recordings before and during supervised, graded, twice weekly, exercise sessions. Hourly temperature measurements were made at a monitoring site near the rehabilitation center.

RESULTS

Using linear mixed models, we observed decreases in rMSSD (square root of the mean of the sum of the squared differences between adjacent NN intervals) and deceleration capacity, associated with increases in ambient temperature in the previous four days. Additionally, decreased rMSSD was associated with both increasing temperature (mean in previous 6 hours) in the summer and decreasing temperature (mean in the previous 3 weeks) in the winter.

CONCLUSIONS

In a panel of cardiac rehabilitation patients, changes in ambient temperature were associated with decreases in markers of heart rate variability and baroreflex sensitivity, which may lead to increased risk of arrhythmic events and sudden death in post-infarction patients.

The health of children looked after by local authorities

There are some 40,000 children 'in care' in England and Wales, i.e. being 'looked after' by local authorities and living in foster and residential homes. These children come from highly disadvantaged social backgrounds and are likely to experience more serious health problems than the wider population. Despite this, there is evidence to suggest that their health needs are frequently neglected. This is reflected in the dearth of research information. Health professionals play a key role in combating child abuse and are particularly concerned about future mental health, self-injury and high levels of pregnancy in this group of children. Health promotion is therefore vital, but is complicated by the fact that this group of children often do not attend school. The Department of Health has introduced a major initiative which has a strong health dimension to help promote better care planning and monitoring for children who have been separated from their parents.

Integrating asthma hazard characterization methods for consumer products

Despite extensive study, definitive conclusions regarding the relationship between asthma and consumer products remain elusive. Uncertainties reflect the multi-faceted nature of asthma (i.e., contributions of immunologic and non-immunologic mechanisms). Many substances used in consumer products are associated with occupational asthma or asthma-like syndromes. However, risk assessment methods do not adequately predict the potential for consumer product exposures to trigger asthma and related syndromes under lower-level end-user conditions. A decision tree system is required to characterize asthma and respiratory-related hazards associated with consumer products. A system can be built to incorporate the best features of existing guidance, frameworks, and models using a weight-of-evidence (WoE) approach. With this goal in mind, we have evaluated chemical hazard characterization methods for asthma and asthma-like responses. Despite the wealth of information available, current hazard characterization methods do not definitively identify whether a particular ingredient will cause or exacerbate asthma, asthma-like responses, or sensitization of the respiratory tract at lower levels associated with consumer product use. Effective use of hierarchical lines of evidence relies on consideration of the relevance and potency of assays, organization of assays by mode of action, and better assay validation. It is anticipated that the analysis of existing methods will support the development of a refined WoE approach.

GTF2IRD1 regulates transcription by binding an evolutionarily conserved DNA motif ‘GUCE’

GTF2IRD1 is a member of a family of transcription factors whose defining characteristic is varying numbers of a helix-loop-helix like motif, the I-repeat. Here, we present functional analysis of human GTF2IRD1 in regulation of three genes (HOXC8, GOOSECOID and TROPONIN I(SLOW)). We define a regulatory motif (GUCE-GTF2IRD1 Upstream Control Element) common to all three genes. GUCE is bound in vitro by domain I-4 of GTF2IRD1 and mediates transcriptional regulation by GTF2IRD1 in vivo. Definition of this site will assist in identification of other downstream targets of GTF2IRD1 and elucidation of its role in the human developmental disorder Williams-Beuren syndrome.

Trimerization of collagen IX alpha-chains does not require the presence of the COL1 and NC1 domains

Collagen IX is a heterotrimer of three alpha-chains, which consists of three COL domains (collagenous domains) (COL1-COL3) and four NC domains (non-collagenous domains) (NC1-NC4), numbered from the C-terminus. Although collagen IX chains have been shown to associate via their C-terminal NC1 domains and form a triple helix starting from the COL1 domain, it is not known whether chain association can occur at other sites and whether other collagenous and non-collagenous regions are involved. To address this question, we prepared five constructs, two long variants (beginning at the NC4 domain) and three short variants (beginning at the COL2 domain), all ending at the NC2 domain (or NC2 replaced by NC1), to study association and selection of collagen IX alpha-chains. Both long variants were able to associate with NC1 or NC2 at the C-terminus and form various disulfide-bonded trimers, but the specificity of chain selection was diminished compared with full-length chains. Trimers of the long variant ending at NC2 were shown to be triple helical by CD. Short variants were not able to assemble into disulfide-bonded trimers even in the presence of both conserved cysteine residues from the COL1-NC1 junction. Our results demonstrate that collagen IX alpha-chains can associate in the absence of COL1 and NC1 domains to form a triple helix, but the COL2-NC2 region alone is not sufficient for trimerization. The results suggest that folding of collagen IX is a co-operative process involving multiple COL and NC domains and that the COL1-NC1 region is important for chain specificity.

Child prostitution: reaching out to children who sell sex to survive

Childhood prostitution is an area that most health-care workers do not come into direct contact with other than through media coverage. It is difficult to obtain a national picture of the scale of the problems associated with childhood prostitution as research has been sparse, fragmented and mainly localized Health and social care professionals need to be aware of the factors that influence routes into prostitution such as childhood abuse, poverty and breakdowns in family relationships if they are to provide relevant and appropriate health promotion interventions. This article explores the social economical and political issues surrounding childhood prostitution, and highlights come interesting initiatives which have been implemented by health and social care professionals.

Pneumothorax secondary to foreign body inhalation in a 20 month old child

A 20 month old child presented with acute onset of respiratory embarrassment as a result of a left-sided tension pneumothorax. This proved to be caused by inhalation of an unusual foreign body: the hair from a rag doll.

Differential effects of ibuprofen and indomethacin in the regional circulation of the dog

The effects of indomethacin and ibuprofen on aortic blood pressure and regional vascular resistances were studied in pentobarbital-anesthetized dogs. In the mesenteric vascular bed, indomethacin produced severe, acute vasoconstriction when administered by i.v. infusion as well as by i.a. injections. Tachyphylaxis developed rapidly to this response. In contrast. ibuprofen did not alter mesenteric blood flow even when a large (50 mg) i.v. bolus was rapidly injected. The mesenteric vasoconstrictor response to indomethacin was not modified when prostaglandin synthesis was inhibited or in the presence of cyproheptadine. Phentolamine exerted only a minor influence on the mesenteric vascular effect of indomethacin. The effects of indomethacin and ibuprofen on aortic blood pressure and renal blood flow were similar. Both agents increased aortic pressure and decreased renal blood flow a small but significant amount, but these responses occurred slowly and were probably not related to the acute mesenteric vasoconstricting effect or indomethacin. The present study demonstrates that these nonsteroidal anti-inflammatory agents have different effects on the mesenteric vascular bed and the data suggest that the vasoconstricting effects of indomethacin are not related to the inhibition of prostaglandin synthesis in the intestine. The data also suggest that the acute vasoconstriction in the mesenteric circulation produced by indomethacin is not mediated to a significant degree by local release of alpha adrenergic agents or serotonin.

Prevention of respiratory infections in adults. Influenza and pneumococcal vaccines

Influenza and pneumococcal infections are important causes of hospitalization and death among individuals who are elderly or who have chronic illnesses. Influenza and pneumococcal vaccines may prevent these infections and their complications, but most high-risk patients have not received them. Doubts about their effectiveness, fears of side effects, and the lack of programs to promote their use contribute to the underuse of these vaccines. Although adequate controlled trials in high-risk patients are lacking, there is observational evidence that they are moderately effective, reducing serious complications of influenza and pneumococcal infections by about one-half. They are cost-effective compared with other preventive interventions and may be cost saving. Their safety has been demonstrated in numerous studies. Health care providers should promote influenza and pneumococcal vaccination. Strategies that have been shown to be successful in increasing the use of these vaccines include provider education and feedback, flagging charts of vaccination candidates, mailed reminders to patients without fall appointments, standing orders for nurses to administer the vaccines, walk-in vaccination clinics, and vaccination of hospitalized patients at discharge.

Autosomal dominant inheritance of Williams-Beuren syndrome in a father and son with haploinsufficiency for FKBP6

Williams-Beuren syndrome (WBS) is a neurodevelopmental microdeletion disorder that usually occurs sporadically due to its location within a highly repetitive genomic region that is unstable and prone to unequal cross-over during meiosis. The consequential loss of chromosomal material includes approximately 1.5 Mb of DNA at 7q11.23. Whilst cases of dominant inheritance have been described in the literature, there have been few reports of molecular confirmation and none have carried out detailed genotyping. We describe a Bulgarian father and son with WBS detected by fluorescent in situ hybridisation (with an elastin gene probe) and loss of heterozygosity mapping using microsatellite markers located in the critical region. These individuals appear to have a common WBS heterozygous deletion, confirming the expected dominant transmission and adding to the few familial cases reported. The deletion includes the gene FKBP6 which has recently been shown to play a role in homologous chromosome pairing in meiosis and male fertility in mouse models. Homozygous Fkbp6 -/- male mice are infertile and our data suggests that haploinsufficiency for FKBP6 does not appear to preclude male fertility in WBS, although male infertility involving this gene has the potential to follow the mouse model as a human autosomal recessive condition.