Field Survey Measures of Olfaction: The Olfactory Function Field Exam (OFFE)

Population-based field research on human olfaction has been limited by a lack of feasible assessment tools. Previous olfactory survey research has measured only odor identification, with no research being done on odor detection (i.e., a person's sensitivity to detect a particular odor). Laboratory studies suggest that deficits in both aspects of olfactory function may be related to physical health, mental health and cognition, social function, including overall quality of life, and even mortality. However, field studies are needed to validate and extend these findings in large representative samples. Here we describe the olfactory function field exam, an instrument that can be deployed in field environments by lay interviewers to evaluate both odor identification and odor detection rapidly, practically, and accurately. Use of this new survey tool in future field-based population health studies will elucidate the impact of olfactory function on a myriad of health and social conditions.

Olfactory dysfunction predicts 5-year mortality in older adults

Prediction of mortality has focused on disease and frailty, although antecedent biomarkers may herald broad physiological decline. Olfaction, an ancestral chemical system, is a strong candidate biomarker because it is linked to diverse physiological processes. We sought to determine if olfactory dysfunction is a harbinger of 5-year mortality in the National Social Life, Health and Aging Project [NSHAP], a nationally representative sample of older U.S. adults. 3,005 community-dwelling adults aged 57–85 were studied in 2005–6 (Wave 1) and their mortality determined in 2010–11 (Wave 2). Olfactory dysfunction, determined objectively at Wave 1, was used to estimate the odds of 5-year, all cause mortality via logistic regression, controlling for demographics and health factors. Mortality for anosmic older adults was four times that of normosmic individuals while hyposmic individuals had intermediate mortality (p<0.001), a “dose-dependent” effect present across the age range. In a comprehensive model that included potential confounding factors, anosmic older adults had over three times the odds of death compared to normosmic individuals (OR, 3.37 [95%CI 2.04, 5.57]), higher than and independent of known leading causes of death, and did not result from the following mechanisms: nutrition, cognitive function, mental health, smoking and alcohol abuse or frailty. Olfactory function is thus one of the strongest predictors of 5-year mortality and may serve as a bellwether for slowed cellular regeneration or as a marker of cumulative toxic environmental exposures. This finding provides clues for pinpointing an underlying mechanism related to a fundamental component of the aging process.

The effect of nasal structure on olfactory function in patients with OSA

The aim of this study was to investigate the relationship between nasal structure and olfactory function in patients with obstructive sleep apnea (OSA). Olfaction and nasal structure of 76 adults with OSA diagnosed by polysomnography were measured using acoustic rhinometry and the Sniffin, Sticks (SS) smell test at Anzhen Hospital, a major academic center in Beijing, China. We tested the hypothesis that nasal structure in these patients would correlate with objectively measured olfactory performance. Minimum cross-sectional area (MCA) of the nose was significantly correlated with SS composite score (r = 0.434, p < 0.001), a result that was driven by two of the test's three components: olfactory threshold (OT) (r = 0.385, p = 0.001) and olfactory discrimination (OD) (r = 0.370, p = 0.001) but not olfactory identification (OI) (p > 0.05). Additionally, nasal volume (NV) was associated with composite SS score (r = 0.350, p = 0.002), a finding driven by OT (r = 0.283, p = 0.014). These data suggest that nasal structure affects parameters of olfactory function, likely via alterations in nasal airflow. Thus, anatomic abnormalities and diseases involving airflow (such as OSA) may cause, in part, olfactory dysfunction that is amenable to treatment. We speculate that surgery that alters nasal volume and MCA may improve olfactory performance.

Effect of prednisone on nasal symptoms and peripheral blood T-cell function in chronic rhinosinusitis

BACKGROUND

Systemic corticosteroids are the most effective anti-inflammatory drugs used for controlling chronic rhinosinusitis (CRS) symptoms. The potential mechanisms for their beneficial effects include increasing the number and function of T regulatory cells (Tregs), as reported in the local tissue post-intranasal steroid treatment. We investigated the effect of systemic corticosteroids on peripheral blood (PB) Tregs in subjects with CRS.

METHODS

Twenty CRS subjects and 19 controls were recruited. PB mononuclear cells (PBMCs) were isolated from CRS subjects before and after systemic corticosteroid administration in the course of clinical treatment. Control subjects received no treatment and were studied at one visit. Nasal symptoms were recorded. CD4(+) CD25(+) Foxp3(+) cells (Tregs) were analyzed by flow cytometry. Messenger RNA (mRNA) levels for interferon γ (IFN-γ), interleukin 4 (IL-4), IL-10, IL-13, IL-17A, transforming growth factor β1 (TGF-β1), forkhead box P3 (FoxP3), and GATA-binding factor 3 (GATA-3) were measured in PBMCs using real-time polymerase chain reaction (PCR).

RESULTS

CRS subjects reported improved nasal symptoms (p = 0.005) and significantly reduced PB Tregs after treatment with corticosteroids (p = 0.042). The transcript levels of IL-4 and GATA-3 were significantly higher in the CRS subjects at their first visit when compared to controls (p = 0.019 and p = 0.05, respectively). Corticosteroid treatment lowered the transcript levels of immunoregulatory transcription factors [FoxP3 (p = 0.048) and GATA-3 (p = 0.012)] and IFN-γ (p = 0.036) in PB.

CONCLUSION

In contrast to prior work in local nasal tissue, our study reports reduced PB Tregs and decreased T helper 1 (T(H)1) and T(H)2 function after treatment with systemic corticosteroids. These data indicate that corticosteroid effects on Tregs in CRS are complex involving local signals in the tissue that are distinct from those in circulating cells.

Olfaction: anatomy, physiology, and disease

The olfactory system is an essential part of human physiology, with a rich evolutionary history. Although humans are less dependent on chemosensory input than are other mammals (Niimura 2009, Hum. Genomics 4:107-118), olfactory function still plays a critical role in health and behavior. The detection of hazards in the environment, generating feelings of pleasure, promoting adequate nutrition, influencing sexuality, and maintenance of mood are described roles of the olfactory system, while other novel functions are being elucidated. A growing body of evidence has implicated a role for olfaction in such diverse physiologic processes as kin recognition and mating (Jacob et al. 2002a, Nat. Genet. 30:175-179; Horth 2007, Genomics 90:159-175; Havlicek and Roberts 2009, Psychoneuroendocrinology 34:497-512), pheromone detection (Jacob et al. 200b, Horm. Behav. 42:274-283; Wyart et al. 2007, J. Neurosci. 27:1261-1265), mother-infant bonding (Doucet et al. 2009, PLoS One 4:e7579), food preferences (Mennella et al. 2001, Pediatrics 107:E88), central nervous system physiology (Welge-Lüssen 2009, B-ENT 5:129-132), and even longevity (Murphy 2009, JAMA 288:2307-2312). The olfactory system, although phylogenetically ancient, has historically received less attention than other special senses, perhaps due to challenges related to its study in humans. In this article, we review the anatomic pathways of olfaction, from peripheral nasal airflow leading to odorant detection, to epithelial recognition of these odorants and related signal transduction, and finally to central processing. Olfactory dysfunction, which can be defined as conductive, sensorineural, or central (typically related to neurodegenerative disorders), is a clinically significant problem, with a high burden on quality of life that is likely to grow in prevalence due to demographic shifts and increased environmental exposures.

Racial disparities in olfactory loss among older adults in the United States

BACKGROUND

Age-related olfactory loss (presbyosmia) substantially decreases quality of life, presages neurodegenerative disease, impairs nutrition, and predicts mortality. We sought to determine how race is associated with olfactory loss in older American adults in order to inform both health care and policy.

METHODS

The National Social Life, Health and Aging Project interviewed a cross-sectional nationally representative probability sample of older adults in the United States. African Americans and Hispanics were oversampled, providing power to detect disparities for these subgroups. As part of an omnibus survey of demographic, social, psychological, and biological measures, National Social Life, Health and Aging Project assessed the ability to verbally identify odors by presenting five odor pens. Multivariate ordinal logistic regression quantified racial differences in odor identification, and then tested potential confounders.

RESULTS

African Americans and Hispanics had markedly worse olfactory function (controlling for gender and age) compared with whites (p < .001), twice the magnitude of gender differences, and comparable to aging 9 years. Cognition, household assets, and education accounted for the disparity found among Hispanics but not among African Americans. Moreover, other potential confounders, such as physical or mental health, including tobacco and alcohol use, did not account for the African American health disparity, which remained significant (p = .001) after including these factors.

CONCLUSIONS

African Americans are more likely to suffer from presbyosmia, a health disparity not explained by gender, education, cognition, physical or mental health, and health behaviors. This novel health disparity may result from lifetime environmental exposures, diet, or genetic susceptibility. Dissecting the interactions among these putative mechanisms will provide insight into ameliorating this decline in critical human sensory function.

Peripheral blood and tissue T regulatory cells in chronic rhinosinusitis

BACKGROUND

The pathogenesis of chronic rhinosinusitis (CRS) has not been fully elucidated. Increased inflammatory cell infiltration and decreased numbers and/or impaired function of T regulatory cells (Tregs) have been reported. This study aimed to determine the role of Tregs in CRS in peripheral blood (PB) and sinus tissue.

METHODS

Sinus tissue was obtained from 16 CRS subjects and 5 controls. PB from additional 16 CRS subjects and total 20 controls was obtained. Immunohistochemical analysis (CD3(+), CD4(+), CD8(+), and Treg [CD4(+)-FoxP3(+) and CD25(+)-FoxP3(+)] cells) of sinus tissue was performed. Percentage of PB Tregs (CD4(+)-CD25(+)-FoxP3(+) cells) was analyzed by flow cytometry. Spontaneous and phytohemagglutinin (PHA)-induced release of cytokines (IL-6, IL-4, IL-10, interferon gamma, transforming growth factor [TGF] beta1, and TNF-alpha) from PB mononuclear cells (PBMCs) was determined.

RESULTS

PB flow cytometric analysis revealed a lower percentage of Tregs in subjects with CRS compared with healthy controls (p = 0.0003). Although no differences in the PB Treg counts were observed between the CRS subjects with nasal polyposis (CRSwNP) and without nasal polyposis (CRSsNP), immunohistochemical analysis performed on sinus tissue revealed a higher proportion of Tregs in CRSwNP subjects compared with CRSsNP (p < 0.05). Additionally, we failed to detect any Tregs from control sphenoid sinus tissue. Lower levels of regulatory cytokines (IL-10 and TGF-β1) and higher levels of proinflammatory cytokines (TNF-α and IL-6) were found from PBMCs from CRS subjects compared with controls (p < 0.05).

CONCLUSION

Our findings suggest that CRS subjects exhibit a decreased percentage of PB Tregs compared with normal controls. PBMCs from CRS subjects show a more proinflammatory and less regulatory phenotype.

Genetics of chronic rhinosinusitis: state of the field and directions forward

The cause of chronic rhinosinusitis (CRS) remains unclear. Study of the genetic susceptibility to CRS might be a valuable strategy to understand the pathogenesis of this burdensome disorder. The purpose of this review is to critically evaluate the current literature regarding the genetics of CRS in a comprehensive fashion. The most promising findings from candidate gene studies include the cystic fibrosis transmembrane conductance regulator gene (CFTR), as well as genes involved in antigen presentation, innate and adaptive immune responses, tissue remodeling, and arachidonic acid metabolism. We also review the few hypothesis-independent genetic studies of CRS (ie, linkage analysis and pooling-based genome-wide association studies). Interpretation of the current literature is limited by challenges with study design, sparse replication, few functional correlates of associated polymorphisms, and inadequate examination of linkage disequilibrium or expression quantitative trait loci for reported associations. Given the relationship of CRS to other airway disorders with well-characterized genetic components (eg, asthma), study of the genetics of CRS deserves increased attention and investment, including the organization of large, detailed, and collaborative studies to advance knowledge of the mechanisms that underlie this disorder.

General olfactory sensitivity database (GOSdb): candidate genes and their genomic variations

Genetic variations in olfactory receptors likely contribute to the diversity of odorant-specific sensitivity phenotypes. Our working hypothesis is that genetic variations in auxiliary olfactory genes, including those mediating transduction and sensory neuronal development, may constitute the genetic basis for general olfactory sensitivity (GOS) and congenital general anosmia (CGA). We thus performed a systematic exploration for auxiliary olfactory genes and their documented variation. This included a literature survey, seeking relevant functional in vitro studies, mouse gene knockouts and human disorders with olfactory phenotypes, as well as data mining in published transcriptome and proteome data for genes expressed in olfactory tissues. In addition, we performed next-generation transcriptome sequencing (RNA-seq) of human olfactory epithelium and mouse olfactory epithelium and bulb, so as to identify sensory-enriched transcripts. Employing a global score system based on attributes of the 11 data sources utilized, we identified a list of 1,680 candidate auxiliary olfactory genes, of which 450 are shortlisted as having higher probability of a functional role. For the top-scoring 136 genes, we identified genomic variants (probably damaging single nucleotide polymorphisms, indels, and copy number deletions) gleaned from public variation repositories. This database of genes and their variants should assist in rationalizing the great interindividual variation in human overall olfactory sensitivity (http://genome.weizmann.ac.il/GOSdb).

Emergency airway management: training and experience of chief residents in otolaryngology and anesthesiology

BACKGROUND

Resident training in emergency airway management is not well described. We quantified training and exposure to airway emergencies among graduating Otolaryngology-Head and Neck Surgery and Anesthesiology residents.

METHODS

The methods used for this study were a national web-based survey of chief residents.

RESULTS

The response rate was 52% (otolaryngology) and 60% (anesthesiology). More otolaryngology residents rotated on anesthesiology than anesthesia residents on otolaryngology (33% vs 8%). More anesthesiology chiefs never performed an emergency surgical airway than otolaryngology (92% vs 18%). The most common self-rating of competency was "9," with 82% overall self-rating "8" or higher (10 = "totally competent").

CONCLUSION

Otolaryngology and anesthesiology emergency airway management experience/training is heterogeneous and nonstandardized. Many chief residents graduate with little exposure to airway emergencies, especially surgical airways. Resident confidence levels are high despite minimal experience. This high confidence-low experience dichotomy may reflect novice overconfidence and suggests the need for improved training methods.

Recruitment factors which affect the outcome of a seasonal allergic rhinitis trial

Although intranasal corticosteroids (INSs) are the first-line treatment for seasonal allergic rhinitis (SAR), some patients do not respond adequately, reflecting biological heterogeneity or confounding conditions. The objective of this study was to determine what recruitment factors identify SAR subjects who will be unresponsive to mometasone furoate (MF). We performed a 2-week, double-blind, placebo-controlled, parallel study on 40 subjects with SAR. Each subject underwent a decongestant test using oxymetazoline. Baseline nasal symptoms, nasal peak inspiratory flow (NPIF) and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) scores were recorded. Next, subjects were randomized to either 200 μg of MF or placebo. Symptom diaries and NPIF measurements were completed twice daily. After 2 weeks, subjects repeated the RQLQ and the global assessment of symptoms. There was a significant reduction in symptoms in the MF group compared with placebo (p ≤ 0.05) in patients with baseline total symptom scores of ≥6. Multivariate analysis showed that treatment (MF versus placebo; p = 0.049) and amount of decongestion (percent change in NPIF after oxymetazoline; p = 0.008) predicted the improvement in total nasal symptoms. In clinical trials, SAR subjects must report multiple symptoms to be responsive to treatment with INSs. Our results also support the use of the decongestant test for choice of appropriate study volunteers, both to ensure participation of potentially responsive subjects and to eliminate those with confounding issues.

A randomized, double-blind, placebo-controlled trial of anti-IgE for chronic rhinosinusitis

Evidence suggests IgE may play a role in chronic rhinosinusitis (CRS). We sought to determine if treatment with a monoclonal antibody against IgE (omalizumab) is effective in reducing CRS inflammation. We performed a randomized, double blind, placebo controlled clinical trial in subjects with CRS despite treatment (including surgery). Subjects were randomized to receive omalizumab or placebo for 6 months. The primary outcome was quantitative measurement of sinus inflammation on imaging. Secondary outcome measures included quality of life, symptoms, and cellular inflammation, nasal airflow (NPIF) and olfactory testing (UPSIT). Subjects on omalizumab showed reduced inflammation on imaging after treatment, whereas those on placebo showed no change. The net difference, however, was not different between treatments. Treatment with omalizumab was associated with improvement in the Sino-Nasal Outcome Test (SNOT-20) at 3, 5, and 6 months compared to baseline with no significant changes in the control group. Remaining measures showed no significant differences across treatments. We conclude that IgE plays, at most, a small role in the mucosal inflammation of CRS and the symptoms. Placebo controlled, blinded studies with larger enrollment are needed to determine the clinical significance of any potential change.

Olfactory Cleft Inflammation is Present in Seasonal Allergic Rhinitis and is Reduced with Intranasal Steroids

Background

Allergic rhinitis (AR) is commonly associated with olfactory loss, although the mechanism is not well studied. This study was designed to determine the effect of mometasone furoate (MF) on olfactory loss in seasonal AR (SAR) and study its effect on inflammation in the olfactory region.

Methods

We performed a randomized, double-blind, placebo-controlled, parallel clinical trial in 17 patients with SAR who had symptoms of impaired olfaction. Subjects received MF or placebo for 2 weeks during their allergy season. Before and after treatment, we measured nasal peak inspiratory flow (NPIF), chemosensory quality of life, and objective olfactory function (the University of Pennsylvania Smell Identification Test). Additionally, nasal cytology samples were obtained from each visit, and a unilateral endoscopic biopsy specimen of the olfactory epithelium was obtained at the end of the study and scored for inflammation.

Results

Treatment with MF was associated with improved nasal symptoms (p < 0.015), NPIF (p < 0.04), reduced nasal inflammation (p < 0.05), and chemosensory-specific quality of life (p < 0.03). Histological analysis of the olfactory region reveals fewer eosinophils in the MF group when compared with placebo (p < 0.012). We found no improvement in objective olfactory function (p > 0.05).

Conclusion

The use of MF in SAR is associated with reduced eosinophilic inflammation in the olfactory region and improved symptoms of AR. The presence of eosinophils in the olfactory area in SAR may indicate a direct, deleterious effect of inflammation on olfactory epithelium in this disease. In this study we show that inflammation in SAR can affect the olfactory cleft, implicating a direct role for allergic inflammation in smell loss. Treatment with intranasal steroids is associated with decreased inflammation in the olfactory region in humans. This treatment is also associated with improved olfactory quality of life.

Rhinitis in the geriatric population

The current geriatric population in the United States accounts for approximately 12% of the total population and is projected to reach nearly 20% (71.5 million people) by 20301. With this expansion of the number of older adults, physicians will face the common complaint of rhinitis with increasing frequency. Nasal symptoms pose a significant burden on the health of older people and require attention to improve quality of life. Several mechanisms likely underlie the pathogenesis of rhinitis in these patients, including inflammatory conditions and the influence of aging on nasal physiology, with the potential for interaction between the two. Various treatments have been proposed to manage this condition; however, more work is needed to enhance our understanding of the pathophysiology of the various forms of geriatric rhinitis and to develop more effective therapies for this important patient population.

Clinical presentation and management of geriatric rhinitis

The population of Americans over 65 years of age is growing at an unprecedented rate. Rhinitis is a common and burdensome complaint in this group, and physicians should be aware of the diagnosis and management of the disease. Geriatric rhinitis is a nasal disorder of older persons that presents with a constellation of nasal symptoms. The etiologies of this condition include both inflammatory diseases and the effects of aging on physiology of the upper airway. Possible causes include allergic rhinitis, nonallergic rhinitis (vasomotor rhinitis and gustatory rhinitis), adverse effects of medications, hormonal changes, postnasal drip syndrome, chronic rhinosinusitis and atrophic rhinitis. Nasal symptoms in the older patient present a clinical challenge because of the physiologic effects of the aging nose, the unusual clinical presentation, the presence of multiple comorbidities and the problem of polypharmacy. A number of therapeutic options exist for this disorder, although definitive studies of effective regimens are needed.

Recovery of otoacoustic emission function in luetic endolymphatic hydrops: a possible measure of improvement in cochlear function

Syphilis is a preventable and curable multi-organ disease caused by Treponema pallidum that may also affect the inner ear. First reported in 1887 by Adam Politzer, luetic endolymphatic hydrops (LEH) is a treatable complication of syphilis which causes a potentially reversible sensorineural hearing loss. Symptoms of LEH include fluctuating hearing loss (often low frequency), tinnitus, and vertigo. Though audiometric parameters have been examined in patients with otosyphilis, few studies have examined the use of otoacoustic emissions (OAEs) as a tool to measure improvement in cochlear function. Here we report an improvement in hearing loss, speech discrimination, and OAEs following treatment of LEH.

A genomewide screen for chronic rhinosinusitis genes identifies a locus on chromosome 7q

OBJECTIVE/HYPOTHESIS

Chronic rhinosinusitis (CRS) is an important public health problem with substantial impact on patient quality of life and health care costs. We hypothesized that genetic variation may be one factor that affects this disease.

STUDY DESIGN

Identification of genetic variation underlying susceptibility to CRS using linkage analysis in a founder population.

METHODS

We studied a religious isolate that practices a communal lifestyle and shares common environmental exposures. Using physical examination, medical interviews, and a review of medical records, we identified eight individuals with CRS of 291 screened. These eight individuals were related to each other in a single 60 member, nine generation pedigree. A genome-wide screen for loci influencing susceptibility to CRS using 1123 genome-wide markers was conducted.

RESULTS

The largest linkage peak (P = .0023; 127.15 cM, equivalent to limit of detection = 2.01) was on chromosome 7q31.1-7q32.1, 7q31 (127.15 cM; 1-limit of detection support region: 115-135 cM) and included the CFTR locus. Genotyping of 38 mutations in the CFTR gene did not reveal variation accounting for this linkage signal.

CONCLUSIONS

Understanding the genes involved in CRS may lead to improvements in its diagnosis and treatment. Our results represent the first genome-wide screen for CRS and suggest that a locus on 7q31.1-7q32.1 influences disease susceptibility. This may be the CFTR gene or another nearby locus.

Effect of changing airway pressure on the ability of the human nose to warm and humidify air

OBJECTIVES

Nasal continuous positive airway pressure (CPAP) treatment causes nasal symptoms that are believed to result from the drying effects of the air on the nasal mucosa, and these symptoms affect compliance with therapy. We hypothesized that the increased air pressure on the nasal mucosa caused by positive pressure from CPAP would decrease the ability of the nose to warm and humidify inspired air, explaining these symptoms.

METHODS

We performed a 4-way crossover trial using CPAP pressures of -5, 0, +5, and +10 cm H2O in 10 subjects. The ability to warm and humidify inspired air was determined by measurement of the temperature of a fixed volume of cold, dry air entering and exiting the nostril and calculation of the amount of water supplied to the airstream by the nose.

RESULTS

The water content of air was unaffected at the pressures studied.

CONCLUSIONS

The pressure of delivered CPAP does not affect the ability of the nose to warm and humidify inspired air.

Familial aggregation of nasal conditioning capacity

In our previous studies on nasal conditioning, we observed a large variability among individuals to condition inspired air. Although we previously investigated various physiological parameters (age, sex, nasal mucosal temperature, heart rate, blood pressure, and nasal volume) that might underlie these differences, we have been unable to explain this variability. Many proteins and molecules, which are under genetic control and could affect nasal conditioning, are involved in water transport,. In this study, we hypothesized that familial factors may contribute to the differences in nasal conditioning capacity (NCC). We performed a prospective study of 47 sibling pairs. Cold dry air was delivered to the nose, and the total water gradient (TWG) was calculated to determine the NCC. We found a highly significant intraclass correlation of 0.53 (P < 0.0001) between sibling pairs for the TWG. These results suggest that there is a familial basis for nasal conditioning and a large enough genetic component to search for genes explaining the observed correlation.

Characterizing the expression of the human olfactory receptor gene family using a novel DNA microarray

BACKGROUND

Olfactory receptor (OR) genes were discovered more than a decade ago, when Buck and Axel observed that, in rats, certain G-protein coupled receptors are expressed exclusively in the olfactory epithelium. Subsequently, protein sequence similarity was used to identify entire OR gene repertoires of a number of mammalian species, but only in mouse were these predictions followed up by expression studies in olfactory epithelium. To rectify this, we have developed a DNA microarray that contains probes for most predicted human OR loci and used that array to examine OR gene expression profiles in olfactory epithelium tissues from three individuals.

RESULTS

We detected expression of 437 (76%) human OR genes in these olfactory epithelia. Interestingly, we detected widespread expression of OR pseudogenes, an observation that may shed light on the mechanism of OR gene choice in the olfactory sensory neurons. To address the hypothesis that OR genes may carry out additional functions, we also characterized the expression of OR genes in a number of non-olfactory tissues.

CONCLUSION

While our results corroborate the functional annotation of the majority of predicted human odorant receptors, we find that a large number of putative human OR genes are expressed in non-olfactory tissues, sometimes exclusively so. Our evolutionary analysis of ectopically expressed human OR genes does not lend support to the hypothesis that these genes have alternative functions.

Effects of saline sprays on symptoms after endoscopic sinus surgery

BACKGROUND

Topical saline is commonly recommended after endoscopic sinus surgery. The efficacy in this situation has never been shown.

METHODS

We performed a controlled clinical trial to determine the effect of saline sprays on symptoms after endoscopic sinus surgery. Patients were randomized to receive normal saline (NS; n = 20), buffered hypertonic saline (HS; n = 20), or no spray (n = 20). A questionnaire measured symptoms of nasal obstruction, discharge, pain, headache, and trouble sleeping. Daily pain medication usage was recorded.

RESULTS

Symptom scores over the first 5 postoperative days showed higher nasal discharge scores in the HS group. Day-by-day comparisons showed that the HS group reported significantly higher pain scores during some postoperative days. The NS group showed similar scores to control.

CONCLUSION

NS and HS sprays do not have a beneficial effect on symptoms compared with no treatment. HS sprays enhanced nasal drainage and pain. Our results do not support prescribing saline sprays early after sinus surgery but do not exclude the use of topical saline in other forms or for other uses, although they may be used for other intentions.

Cutting edge: polymorphisms in the ICOS promoter region are associated with allergic sensitization and Th2 cytokine production

The establishment of ICOS as an important regulator of Th2 development and effector function makes the ICOS locus an attractive candidate for Th2-mediated diseases, such as asthma and allergy. In evaluation of this candidate locus in humans, we identified 11 variants and determined that two in the putative promoter region are significantly associated with allergic sensitization and serum IgE levels. In addition, cultures of activated PBMCs from individuals homozygous for the associated polymorphisms produced increased levels of the Th2 cytokines, IL-4, IL-5, and IL-13, as well as TNF-alpha compared with controls. One of the polymorphisms, -1413G/A, demonstrated differential NF-kappaB binding in mobility shift analysis, suggesting that this polymorphism has functional consequences. Overall, these data demonstrate that ICOS is a susceptibility gene for allergic sensitization, perhaps through the promotion of Th2 differentiation.

Alpha-adrenoreceptor blockade with phenoxybenzamine does not affect the ability of the nose to condition air

The primary function of the nose is to warm and humidify air. We have previously shown that raising nasal mucosal temperature by immersing feet in warm water increases the amount of water evaporated by the nose as air passes through it (nasal conditioning capacity; Abbott D, Baroody F, Naureckas E, and Naclerio R. Am J Rhinol 15: 41-45, 2001). To investigate further the effect of nasal mucosal temperature on nasal conditioning capacity, we raised the temperature through alpha-adrenoreceptor blockade by intranasally administering phenoxybenzamine. We hypothesized that blocking alpha-adrenoreceptors during inhalation of cold, dry air would lead to an increase in nasal blood flow, surface temperature, and nasal conditioning capacity, as measured by the water gradient. After appropriate pilot studies, we performed a double-blind, placebo-controlled, two-way crossover study in nine nonatopic, healthy subjects by studying the effect of treatment with intranasal phenoxybenzamine. Nasal mucosal temperature increased significantly after administration of phenoxybenzamine and was associated with a significantly smaller net decrease in nasal mucosal temperature after exposure to cold, dry air (P < 0.05). However, there were no significant differences in nasal conditioning capacity between treatments (P > 0.05). Phenoxybenzamine decreased the symptom of rhinorrhea after exposure to cold, dry air (P < 0.05), but congestion was not different between individuals given phenoxybenzamine and placebo (P > 0.05). Our data demonstrate that phenoxybenzamine, despite raising mucosal temperature and not affecting nasal volume, did not affect the ability of the nose to warm and humidify air.

Efficient MILP formulations for the optimal synthesis of chromatographic protein purification processes

The use of recombinant proteins has increased greatly in recent years, as well as the techniques used for their purification. The selection of an efficient process to purify proteins is a major bottleneck found when trying to scale up results obtained in the laboratory to a large-scale industrial process. One of the main challenges in the synthesis of downstream purification stages in biotechnological processes is the appropriate selection and sequencing of chromatographic steps. The objective of this work is to develop mixed integer linear programming models for the synthesis of protein purification processes. Models for each chromatographic technique rely on physicochemical data of a protein mixture, which contains the desired product and provide information on its potential purification. Formulations that are based on convex hull representations are proposed to calculate the minimum number of steps from a set of chromatographic techniques that must achieve a specified purity level and alternatively to maximize purity for a given number of steps. The proposed models are tested in several examples with experimental data and present time reductions of up to three orders of magnitude when compared to big-M formulations.

Treatment of nasal inflammation decreases the ability of subjects with asthma to condition inspired air

We previously showed that individuals with seasonal allergy have a reduced ability to condition air, which was improved by nasal inflammation. We also showed that subjects with asthma have a reduced ability to condition air. Because individuals with asthma usually have inflammation in the nose, we hypothesized that treatment with an intranasal steroid would reduce nasal inflammation and further decrease nasal conditioning capacity. We performed a randomized, double blind, placebo-controlled, 2-way crossover study on 20 subjects with asthma comparing the effect of treatment with intranasal budesonide for 2 weeks on nasal conditioning. Treatment with budesonide caused no significant effect on nasal conditioning as compared with placebo. When we evaluated the subgroup of nonsmoking subjects, budesonide caused a significant reduction in nasal conditioning. We speculate that nasal inflammation in nonsmoking individuals with asthma increases the conditioning capacity and reducing it with an intranasal steroid worsens the ability of the nose to condition air. In addition, smoking causes an increase in nasal conditioning capacity by non-steroid-dependent factors. These observations help us understand the pathophysiology of nasal conditioning, but do not negate the positive clinical benefits of budesonide on treating nasal inflammation.

Chronic sinusitis and allergic rhinitis: at the nexus of sinonasal inflammatory disease

Allergic rhinitis and sinusitis are two very common diseases that affect the health of the American people and lead to a large amount of health care expenditure. Clinical observations support the close connection between these two diseases. We review existing evidence of the link between these two diseases, stressing the similarities in inflammatory responses between allergic rhinitis and sinusitis. Possible mechanisms underlying these relationships are described.

Process performance models in the optimization of multiproduct protein production plants

In this work we propose a model that simultaneously optimizes the process variables and the structure of a multiproduct batch plant for the production of recombinant proteins. The complete model includes process performance models for the unit stages and a posynomial representation for the multiproduct batch plant. Although the constant time and size factor models are the most commonly used to model multiproduct batch processes, process performance models describe these time and size factors as functions of the process variables selected for optimization. These process performance models are expressed as algebraic equations obtained from the analytical integration of simplified mass balances and kinetic expressions that describe each unit operation. They are kept as simple as possible while retaining the influence of the process variables selected to optimize the plant. The resulting mixed-integer nonlinear program simultaneously calculates the plant structure (parallel units in or out of phase, and allocation of intermediate storage tanks), the batch plant decision variables (equipment sizes, batch sizes, and operating times of semicontinuous items), and the process decision variables (e.g., final concentration at selected stages, volumetric ratio of phases in the liquid-liquid extraction). A noteworthy feature of the proposed approach is that the mathematical model for the plant is the same as that used in the constant factor model. The process performance models are handled as extra constraints. A plant consisting of eight stages operating in the single product campaign mode (one fermentation, two microfiltrations, two ultrafiltrations, one homogenization, one liquid-liquid extraction, and one chromatography) for producing four different recombinant proteins by the genetically engineered yeast Saccharomyces cerevisiae was modeled and optimized. Using this example, it is shown that the presence of additional degrees of freedom introduced by the process performance models, with respect to a fixed size and time factor model, represents an important development in improving plant design.

Lack of utility of postoperative chest radiograph in pediatric tracheotomy

OBJECTIVE

To assess the incidence of pulmonary complications after nonemergent pediatric tracheotomy and to determine whether obtaining a routine postoperative chest radiograph is warranted.

STUDY DESIGN

Retrospective review of the records of 107 consecutive patients (age 1 month to 18 years) who underwent tracheotomy from October 1994 to June 2000. Main outcome measures included frequency of pulmonary complications and use of information obtained from postoperative chest radiograph for intervention.

SETTING

Tertiary care university children's hospital.

RESULTS

No pneumothoraces or significant pulmonary complications were detected in the immediate postoperative period. No management changes were undertaken as a result of information obtained from any chest radiograph in this period.

CONCLUSIONS

The incidence of significant pulmonary complications after pediatric tracheotomy is low. Little information is obtained from chest radiograph after tracheotomy, and this information does not change management.

SIGNIFICANCE

Routine postoperative chest radiograph after pediatric tracheotomy is not indicated in all patients.

Optimal synthesis of protein purification processes

There has been an increasing interest in the development of systematic methods for the synthesis of purification steps for biotechnological products, which are often the most difficult and costly stages in a biochemical process. Chromatographic processes are extensively used in the purification of multicomponent biotechnological systems. One of the main challenges in the synthesis of purification processes is the appropriate selection and sequencing of chromatographic steps that are capable of producing the desired product at an acceptable cost and quality. This paper describes mathematical models and solution strategies based on mixed integer linear programming (MILP) for the synthesis of multistep purification processes. First, an optimization model is proposed that uses physicochemical data on a protein mixture, which contains the desired product, to select a sequence of operations with the minimum number of steps from a set of candidate chromatographic techniques that must achieve a specified purity level. Since several sequences that have the minimum number of steps may satisfy the purity level, it is possible to obtain the one that maximizes final purity. Then, a second model that may use the total number of steps obtained in the first model generates a solution with the maximum purity of the product. Whenever the sequence does not affect the final purity or more generally does not impact the objective function, alternative models that are of smaller size are developed for the optimal selection of steps. The models are tested in several examples, containing up to 13 contaminants and a set of 22 candidate high-resolution steps, generating sequences of six operations, and are compared to the current synthesis approaches.

Systematic study of occult pulmonary thromboembolism in patients with deep venous thrombosis

PURPOSE

This study was carried out to evaluate the prevalence and extension of pulmonary thromboembolism (PTE) in symptom-free patients with symptomatic deep venous thrombosis (DVT) of lower limbs and to evaluate their possible implication in the adequate treatment of thromboembolic disease.

MATERIALS AND METHODS

We prospectively studied, using noninvasive examination (pulmonary spiral computed tomography [CT] angiography), 159 consecutive patients with acute DVT confirmed by duplex scanning without symptoms of PTE. CT was repeated at 30 days to study evolution of these clinically occult PTE.

RESULTS

We observed silent PTE in 65 patients (41%) in all levels of lower limb venous thrombosis. Prevalence of PTE showed significant association with male sex (P =.001) and previously diagnosed heart disease (P =.023). There was no significant association between the level of DVT and the presence of PTE nor the DVT side and thromboembolic pulmonary localization. Of the 65 patients with positive CT exploration results for PTE, 52 had characteristics of acute PTE, 10 had chronic PTE, and 3 patients had both. Chronic PTE was found more frequently in patients with previous episodes of DVT (P =.024). A total of 165 pulmonary artery-affected segments were found at several locations: 5 main, 35 lobar, 58 interlobar, and 67 segmental. Multiple segments were affected in 59% of patients. Repeat CT examinations were performed at 30 days in 53 of 65 patients with positive CT scanning results. In 48 cases (90.6%) PTE had completely disappeared.

CONCLUSIONS

Silent PTE occurred frequently in association with clots of lower limbs. The CT scan had a good availability and cost-effectiveness to detect clinically underestimated PTE. The incorporation of this exploration in the systematic diagnostic strategy of most patients with DVT to establish the extension of thromboembolic disease at diagnosis may be useful in the evaluation of added pulmonary artery symptoms and treatment strategies.

Chronic anisakiasis presenting as a mesenteric mass

Chronic anisakiasis is a rare entity, and its diagnosis is difficult. We report a case of chronic anisakiasis with multiple gastrointestinal manifestations presenting as a palpable mesenteric mass, diagnosed by specific serology and histologic findings. We describe the computed tomographic appearance of this mass and the pathologic correlations. To our knowledge, this is the first time this mesenteric location has been detected by imaging before surgery.

Optimal design of protein production plants with time and size factor process models

In this work we propose an optimization model for the design of a biotechnological multiproduct batch plant. A first level of detail posynomial model is constructed for each unit, as well as decisions regarding the structural optimization of the plant. A particular feature of this model is that it contains composite units in which semicontinuous items operate on the material contained by batch items. This occurs in the purification steps, in particular with the microfilters operating between retentate and permeate vessels, and with the homogenizer and ultrafilters operating on the material contained in a batch holding vessel. Also, the unit models rely on batch operating time expressions that depend on both the batch size and the size of semicontinuous items. The model takes into account all of the available options to increase the efficiency of the batch plant design: unit duplication in-phase and out-of-phase and intermediate storage tanks. The resulting mathematical model for the minimization of the plant capital cost is a mixed integer non-linear program (MINLP), which is solved to global optimality with an implementation of the outer approximation/ equality relaxation/ augmented penalty (OA/ER/AP) method. A plant that produces four recombinant proteins in eight processing stages is used to illustrate the proposed approach. An interesting feature of this example is that it represents an attempt to standardize a plant for the production of both therapeutic and nontherapeutic proteins; the model applied is generic and can thus be applied to any such modular plant. Results indicate that the best solution in terms of minimal capital cost contains no units in parallel and with intermediate storage tank allocation.

[Horner's syndrome and brachial radiculopathy related to vertebral metastases]

INTRODUCTION

Horner's syndrome consists of sympathetic ocular paralysis, with lesions occurring at different levels. When it's associated with involvement of the C8-T1 roots, the commonest causes are the tumours responsible for Pancoast's syndrome.

CLINICAL CASE

We describe the case of a patient who presented with a clinical condition in which a complete right Horner's syndrome was associated with ipsilateral C8-T1 brachial radiculopathy. On investigation, there was a tumour involving the vertebral segments between C8 and T5. Histological studies showed this to be a metastasis from an adenocarcinoma at the base of the right lung.

CONCLUSION

We consider this case to be interesting because of its unusual aetiology, since metastatic vertebral lesions are an uncommon cause of Horner's syndrome.

Effects of mibefradil, a T-type calcium current antagonist, on electrophysiology of Purkinje fibers that survived in the infarcted canine heart

INTRODUCTION

We studied the effects of mibefradil (MIB), a nondihydropyridine T-type Ca2+ channel antagonist, on T- and L-type Ca2+ (I(CaT), I(CaL)) currents in Purkinje myocytes dispersed from the subendocardium of the left ventricle of normal (NZPC) and 48-hour infarcted (IZPC) hearts.

METHODS AND RESULTS

Currents were recorded with Cs+- and EGTA-rich pipettes and in Na+-K+-free external solutions to eliminate overlapping currents. In all cells, I(Ca) was reduced by MIB (0.1 to 10 microM). No change in the time course of decay of peak I(Ca) was noted. Average peak T/L ratio decreased in NZPCs but not IZPCs with 1 microM MIB. Steady-state availability of I(CaL) was altered with 1 microM MIB in both cell types (mean +/- SEM) (V0.5 = -22 +/- 4 mV for NZPC and -25 +/- 5 mV for IZPC before drug; -63 +/- 9 mV for NZPC and -67 +/- 6 mV for IZPC after drug; P < 0.05). For I(CaT), V0.5 (-50 +/- 3 mV for NZPC and -52 +/- 1 mV for IZPC before drug) shifted to -60 +/- 2 mV (NZPC) and -62 +/- 3 mV (IZPC) (P < 0.05) after drug. We also determined the effects of MIB on spontaneously beating Purkinje normal fibers and on depolarized abnormally automatic fibers from the infarcted heart using standard microelectrode techniques. When NZPC and IZPC fibers were superfused with [K+]o = 2.7 mM, MIB 3 microM and 10 microM had no effect on rate or the maximum diastolic potential, but action potential plateau shifted to more negative values, the slope of repolarization phase 3 decreased, and action potential duration increased.

CONCLUSION

MIB blocks L- and T-type Ca2+ currents in Purkinje myocytes but lacks an effect on either normal or abnormal automaticity in Purkinje fibers.

Characteristics of I(K) and its response to quinidine in experimental healed myocardial infarction

INTRODUCTION

Mechanisms and drug treatment of serious ventricular arrhythmias in patients with healed myocardial infarction (HMI) are incompletely understood, in part because the electrophysiology and pharmacology of myocytes from noninfarcted regions of HMI hearts are not well characterized.

METHODS AND RESULTS

We studied the delayed rectifier potassium current (I(K)) and quinidine responsiveness of single left ventricular subendocardial myocytes isolated from the region remote to the border zone of healed infarct myocardium (4 to 6 mm from scar edge) in cat hearts 2 months after coronary artery occlusion. Subendocardial cells isolated from corresponding regions of normal cat hearts provided controls. I(K) activation and tail currents were recorded using whole cell, voltage clamp techniques. Membrane capacitance of cells remote to HMI (187 +/- 7 pF) was significantly greater than normal (155 +/- 6 pF; P < 0.001). Action potential durations (APDs) recorded from myocytes in remote regions were prolonged (APD90 = 247 +/- 10 msec) compared to normal (214 +/- 11 msec; P < 0.05). Quinidine (1 microM) significantly prolonged APD90 in normal cells but not in remote cells. Density of I(K) (tail current) was significantly decreased in remote cells (3.1 +/- 0.3 pA/pF) compared to normal (3.9 +/- 0.3 pA/pF; P < 0.05), and voltage-dependent activation of I(K) was shifted in the positive direction. Quinidine had significantly less incremental blocking effect on I(K) already blunted by regional hypertrophy compared to its effect on normal cells in remote cells. IC50 shifted to 0.95 microM in remote cells compared with 0.50 microM in normal cells.

CONCLUSION

Cells in noninfarct region remote from the scar are hypertrophied and display altered electrophysiology. Their reduced I(K) responsiveness to quinidine may explain, in part, failure of quinidine to prolong APD in such cells. Moreover, dispersion of repolarization may be decreased by the effect of quinidine on normal cells.

Electrical remodeling in ischemia and infarction

This is a review of the electrophysiologic changes occurring at different times following myocardial infarction, both in the infarcted region (substrate) and in areas remote from the infarct. Regulators of channel function which might contribute to re-modeling, including autocrine/paracrine factors involved in ion channel gene regulation, are discussed.

Reduced inward rectifying and increased E-4031-sensitive K+ current density in arrhythmogenic subendocardial purkinje myocytes from the infarcted heart

INTRODUCTION

Subendocardial Purkinje myocytes from the 48-hour infarcted heart (IZPCs) have reduced resting potentials, possibly due to altered inwardly rectifying K+ currents IK1. Abnormal depolarization-activated outward K+ currents could contribute to long triangularly shaped action potentials of IZPCs.

METHODS AND RESULTS

We used whole cell patch recordings to compare cesium-sensitive IK1 and 4-aminopyridine (4-AP)-resistant, noninactivating sustained IK between normal Purkinje myocytes (NZPCs) and IZPCs. IZPCs showed decreased net membrane currents. Two IZPC groups were distinguished, based on 4-AP-resistant outward K+ currents. IZPC-I had isochronal IK1 current-voltage relations similar to NZPCs whereas IZPC-II showed significantly reduced IK1 and increased outward plateau currents. To study the sustained IK in the presence of the Class III antiarrhythmic agent E-4031, a two-pulse protocol was used to inactivate transient outward currents, followed by step depolarizations. E-4031-sensitive currents were significantly greater in IZPCs at depolarized potentials (> 0 mV). Similar to NZPCs, IZPC E-4031 currents showed time dependence during depolarization, lack of rectification at positive steps, and voltage-dependent recovery from block.

CONCLUSION

Decreased IK1 may account for reduced resting potentials in IZPCs. E-4031-sensitive currents in NZPCs, unlike those in canine ventricular myocytes, are sensitive to 4-AP and are larger in IZPCs.

Hypertrophy decreases cardiac KATP channel responsiveness to exogenous and locally generated (glycolytic) ATP

This study tests the hypothesis that glycolytic regulation of KATP channel activity is altered in myocardial hypertrophy. Left ventricular (LV) subendocardial myocytes were isolated from cats with normal or left ventricular hypertrophied hearts (LVH). Saponin-permeabilized open cell-attached patch configurations of normal and LVH cells were exposed to an exogenous ATP consuming system containing hexokinase and 2-deoxyglucose. Phosphoenol pyruvate (PEP, substrate for the last ATP producing step in glycolysis) was applied extracellularly; ADP was present. In both cell types, KATP channels were activated in the absence of PEP, inhibited when PEP was added and activated again when PEP was removed, indicating the cells retained metabolic integrity and generated ATP in the proximity of their KATP channels. Single channel conductance in the absence of PEP was similar (70 pS, normal; 66 pS, LVH). However, LVH KATP channels showed enhanced activity (P0=0.50+/-0.03); normal (0.41+/-0.03) in PEP absence (P<0. 05). PEP responsiveness was reduced in LVH, with IC50, PEP increased to 23 microM; (11 microM normal). Lactate failed to activate KATP channels in both cell types. The concentration-P0 response curves obtained during exposure of open cells to exogenous ATP also revealed reduced responsiveness to ATP of LVH KATP channels (IC50, ATP=283 microM LVH; 93 microM normal). Our data indicate myocardial hypertrophy increases the maximal activity of KATP channels in the absence of ATP and reduces their responsiveness to ATP, including locally generated glycolytic ATP. These alterations in metabolic regulation of myocardial electrophysiology may contribute to diversity of action potential shortening in hypertrophied hearts during acute ischemia.

Regional gradation of L-type calcium currents in the feline heart with a healed myocardial infarct

INTRODUCTION

Abnormal action potentials in myocytes adjacent to > 2-month-old feline LV myocardial infarcts (MI) may reflect alterations in Ca2+ currents (Ica).

METHODS AND RESULTS

We compared ICa, at 36 degrees C, in subendocardial myocytes isolated from areas adjacent to MI and to ICa in cells from remote areas (> 4 mm away; REM) and control cells from similar regions in normal hearts. Control (CON) myocytes had membrane capacitance of 234 +/- 10 pF (n = 81 cells) compared to 305 +/- 14 pF in REM (71 cells; P < 0.05 from CON) and 237 +/- 11 pF (n = 55 cells) in MI (not different from CON). From Vh = -40 mV; peak ICa elicited by test potentials (-35 to +70 mV) were significantly larger in CON (-1746 +/- 123 pA) and REM (-1795 +/- 142 pA) compared to MI (-1352 +/- 129 pA) (P < 0.05). Peak ICa density was significantly reduced in REM (-6.0 +/- 0.4 pA/pF) or MI (-5.7 +/- 0.4 pA/pF, P < 0.05) compared to CON (-7.5 +/- 0.4 pA/pF). Double exponential ICa decay was similar among groups. Half-inactivation potential (V0.5) was significantly shifted (hyperpolarizing direction) for MI (-29.1 +/- 2.6 mV) and REM (-24.6 +/- 1.2 mV) myocytes compared to -20.3 +/- 1.0 mV in CON. MI slope factor (k; 9.0 +/- 0.5) was significantly different from CON (6.8 +/- 0.3) and REM (7.3 +/- 0.4). No differences in time course of recovery from inactivation were noted. Five millimolar Ba2+o produced significant increases in ICa in CON and REM but an attenuated response in MI. Bay K8644 (1 microM) produced similar ICa increase in all groups. ICa increase due to isoproterenol (1 microM) in MI and REM was half that in CON, but there were no differences in increased ICa responses among groups following phenylephrine (10 microM).

CONCLUSION

Reduced ICa density in REM reflects cell hypertrophy, whereas altered ICa of MI may reflect altered channel structure and/or function.

Plasma norepinephrine increased during coronary occlusion in hypertensive pigs that developed ventricular fibrillation

Although hypertension is associated with increased risk of sudden cardiac death, the mechanisms involved remain enigmatic. Little is known about hemodynamic and plasma catecholamine concentration changes during coronary artery occlusion in hypertensive subjects. To study this, 30 pigs were implanted with catheters in the aorta and a silk snare around the left anterior descending coronary artery that could later be pulled to permanently occlude the artery. Perinephritic hypertension was induced in 14 of the animals over 3 weeks by wrapping one kidney in silk followed by contralateral nephrectomy. Coronary artery occlusion (CAO) was carried out in all pigs in the conscious resting state. Ventricular fibrillation (VF) developed in 50% of each group within 15 min after coronary artery occlusion. The hypertensive VF group showed an increase in norepinephrine concentration of 112 +/- 46%; a significantly greater increase than the intact VF group, which showed a 29 +/- 7% increase in norepinephrine concentration 5 min after coronary artery occlusion (p < 0.05).