4 +/- 0.2). Sections from group A animals revealed the mildest EC injury (1.3 +/- 0.3 vs. group D p < 0.01). No significant difference was detected between group A and B. EC injury grade in group C (2.7 +/- 0.6) was higher than that in group B (1.8 +/- 0.6) but did not reach statistical significance (p = 0.58).

Conclusion: When possible, vascular reconstruction following

use of shunts should include an interposition graft after debridement Stem Cell Compound Library price of the arterial edges having interfaced with the shunt. Finally, to minimize intimal injury to the native vessel, this model suggests that indwell times of shunts should be <9 hours.”
“OBJECTIVE: Glucose intolerance is frequently associated with an altered plasma lipid profile and increased cardiovascular Salubrinal chemical structure disease risk. Nonetheless, lipid metabolism is scarcely studied in normolipidemic glucose-intolerant patients. The aim of this study

was to investigate whether important lipid metabolic parameters, such as the kinetics of LDL free and esterified cholesterol and the transfer of lipids to HDL, are altered in glucose-intolerant patients with normal plasma lipids.

METHODS: Fourteen glucose-intolerant patients and 15 control patients were studied; none of the patients had cardiovascular disease manifestations, and they were paired for age, sex, race and co-morbidities. A nanoemulsion resembling a LDL lipid composition (LDE) labeled with C-14-cholesteryl ester and H-3-free cholesterol was intravenously injected, and blood samples were collected over a 24-h period to determine the fractional clearance rate of the labels by compartmental analysis. The transfer of free and esterified cholesterol, triglycerides and phospholipids from the LDE to HDL was measured by the incubation of the LDE with plasma and radioactivity counting

of the supernatant after chemical precipitation of non-HDL fractions.

RESULTS: The levels of LDL, non-HDL and HDL cholesterol, triglycerides, check details apo A1 and apo B were equal in both groups. The 14 C-esterified cholesterol fractional clearance rate was not different between glucose-intolerant and control patients, but the H-3-free- cholesterol fractional clearance rate was greater in glucose-intolerant patients than in control patients. The lipid transfer to HDL was equal in both groups.

CONCLUSION: In these glucose-intolerant patients with normal plasma lipids, a faster removal of LDE free cholesterol was the only lipid metabolic alteration detected in our study. This finding suggests that the dissociation of free cholesterol from lipoprotein particles occurs in normolipidemic glucose intolerance and may participate in atherogenic signaling.”
“Descurainia sophia (flixweed) is an annual weed widely distributed in cultivated crops, forage and rangelands throughout the world. This weed, in particular its seed, is used for food, medicinal and industrial purposes.

40% and 10.70%, respectively). M. alternifolia EO was proved to be toxic against C. capitata and P. concolor. Through contact and fumigation assays, tea tree EO showed lower LC50 values towards C capitata over P. concolor (contact: 0.117 mu Loil/cm(2) vs. 0.147 mu L oil/cm(2); fumigation: 2.239 mu L oil/L air vs. 9.348 mu L oil/L air). In ingestion formulation, the LD50 value was lower in C. capitata (0.269% of EO, w/w) than in P. concolor (0.638% of EO, w/w). This study extends the number

of effective essential oils against the Mediterranean fruit fly and provides useful information for the development of new tephritid CHIR98014 order control tools. This could expidite the building of eco-friendly alternatives in fruit fly integrated control programmes, thus reducing the use of broad-spectrum insecticides. 2013 Elsevier B.V. All rights reserved.”
“The aim of this study was to investigate the influence of acute stress on salivary fluoride selleck products bioavailability. Acute psychological stress was induced using a standardized model of public speaking. The saliva of male subjects was collected before and after the public speaking task

and immediately, 10, 30, and 120 minutes after tooth brushing according to the Bass method with a dentifrice containing amine fluoride (AmF) or oral hygiene tablets containing sodium fluoride (NaF). Subjective psychological responses to public speaking were evaluated using the State-Trait Anxiety Inventory (STAI). Saliva cortisol levels were analyzed as an objective stress marker. The saliva secretion rate was measured both before and after public speaking. Saliva fluoride content was measured. Group comparisons

were calculated using a univariate analysis of variance (ANOVA). In all analyses, the alpha-level was set at 0.05. Public speaking significantly increased state anxiety (p < 0.001) and salivary cortisol concentrations (p < 0.001). Acute stress did not influence salivary secretion rates. In the AmF group, stressed individuals exhibited statistically significant (p=0.044) lower fluoride concentration in saliva compared with the nonstressed subjects Acute psychological stress AZD1480 reactions do not cause hyposalivation but decrease fluoride bioavailability after using a dentifrice containing AmF. Fluoride bioavailability during acute stress is dependent on fluoride formulation.”
“Size exclusion chromatography (SEC) is the most commonly used method to separate and quantify monoclonal antibody (mAb) size variants. MAb-A is an IgG1 subtype humanized monoclonal antibody recombinantly produced in Chinese hamster ovary (CHO) cells. SEC analysis of MAb-A resolved a peak, named Peak 1, which elutes between monomer and dimer peaks. MAb-A lots produced from different clones and production scales all have 0.2-0.3% of SEC Peak 1.

Thus, the health of the sperm genome and epigenome is critical for improving assisted conception rates and the birth of healthy offspring.”
“Purpose

The purpose of this study was to evaluate efficacy and toxicity of irinotecan, leucovorin and 5-fluorouracil (FOLFIRI) as second-line treatment after failure

of oxaliplatin, leucovorin and 5-fluorouracil www.selleckchem.com/products/bi-d1870.html (FOLFOX) for advanced gastric cancer.

Materials and Methods

Patients who received modified FOLFOX-4 as first-line treatment and then received sequential modified FOLFIRI for disease progression were included in this study. The modified FOLFIRI regimen consisted of irinotecan 150 mg/m(2) in a 90-minute intravenous infusion on day 1, leucovorin (LV) 20 mg/m(2) and 5-fluorouracil (5-FU) 400 mg/m(2) as a bolus followed by 600 mg/m(2) as a 22-hour infusion on days 1 and 2 with the same dose of 5-FU/LV of modified FOLFOX-4 every 2 weeks.

Results

A total of 32 patients received 126 courses of FOLFIRI chemotherapy. No complete response was achieved. Three patients (9.4%; 95% confidence interval [CI], 0 to 20.1%) achieved partial response, whereas 11 (34.4%; 95% CI, 17.0 to 51.8%) patients showed stable disease. Disease control

rate (complete response, partial responses and stable diseases) was 43.8% (95% CI, 25.6 to 61.9%) and median follow up duration was 11.3 months (range, 2.23 to 37.9 months). Median time to progression was 2 months (95% CI, 1.49 to 2.51 months), and median overall survival from the start of FOLFIRI Selleck CBL0137 was 5.84 months (95% CI, 4.34 to 7.34 months). Toxicities were tolerable.

Conclusion

Modified FOLFIRI as second-line chemotherapy after failure of the modified FOLFOX-4 in advanced gastric cancer was tolerable but showed a lower response rate. Further

study about retrying 5-FU/LV selleck chemical with irinotecan after failure of the 5-FU/LV combined regimen is necessary in advanced gastric cancer.”
“Background: It is not easy to predict the prognosis of patients receiving extracorporeal life support (ECLS) because of the highly variable situation around its implementation. We evaluated the role of pulse pressure (PP), which is available on real-time basis, as a hemodynamic prognostic marker during ECLS.

Methods: From January 2009 to August 2011, data from 69 patients who were treated with ECLS for at least 6h in a single center for any cause was collected. We calculated the mean PP over the first 6h after ECLS implantation and examined if there was any correlation between mean PP and the study endpoints, in-hospital death and ECLS weaning failure.

Results: The causes of ECLS were of cardiac origin in 36 patients (52%). 27 patients (39.1%) weaned off ELCS and 13 patients (18.8%) survived to discharge.

The cause of resistance to methicillin and all other beta-lactam antibiotics is the mecA gene, which is situated on a mobile genetic element, the Staphylococcal Cassette SCH727965 in vivo Chromosome mec (SCCmec). Seven major variants of SCCmec, type I to VII are distinguished. HA-MRSA disseminated

worldwide and causes the majority of S. aureus nosocomial infections with a limited number of clones disseminated including the Brazilian Epidemic Clone (BEC, ST239-MRSA-III). CA-MRSA isolates are susceptible to non-beta-lactam antibiotics, usually isolated from healthy individuals which do not possess any unknown risk factors for MRSA infection and are associated with a larger clonal diversity compared with HA-MRSA. However, during recent years distinction between HA-MRSA and CA-MRSA is beginning to fade. Actually, knowledge about MRSA disseminating clones is required to implement any strategies to control the transmission of MRSA

either within hospitals or in community. selleck compound For this reason, rapid identification of strains is an important issue. The rate of HA-MRSA can be reduced substantially through the implementation of interventions strategies, even in settings where MRSA is endemic as in most Brazilian hospitals. However, these policies could be quite complicated in the light of an increasing CA-MRSA prevalence in healthcare facilities, considering that distinction between HA-MRSA and CA-MRSA has started to disappear.”
“We present two cases of juvenile form of paracoccidioidomycosis (PCM), a systemic A-1331852 clinical trial mycosis frequently found in rural areas, whose prognosis is poor in children

and young adults. They are a 14-year-old boy and a 25-year-old woman, both residents in an urban area in Sao Paulo – Brazil, without any history of travelling to an endemic area. They have been admitted to the hospital due to fever, weight loss and lymphadenopathy. The diagnosis was confirmed by serologic and histopathologic study. Patients have recovered after therapy with oral itraconazole and were discharged from hospital, maintaining outpatient visits. In this article, the authors discuss the unusual presentation of PCM in an urban area.”
“After allogeneic hematopoietic stem cell transplantation (HSCT), viral infections/reactivations are a frequent complication, sometimes with fatal outcome. Thus, early diagnosis is recommended by screening of whole blood or plasma preparations using highly sensitive molecular techniques that test for the most common viral pathogens, such as EpsteinBarr virus, cytomegalovirus, and adenoviruses (ADVs). Despite this approach, not every reactivation/infection can be adequately detected or excluded, even with highly sensitive polymerase chain reaction. Particularly after toxic treatment, uncommon infections or infections resistant to first-line treatment can occur, even in unusual locations.

In the case presented here, a 52-year-old Chinese female with a lung mass underwent ATM/ATR inhibitor drugs a right upper-middle lobectomy with pulmonary artery sleeve resection and reconstruction, and was thereafter diagnosed with PPL. After 28 months, the patient was well and without local recurrence or distant metastasis. Copyright (C) 2013 Elsevier Taiwan LLC and the Chinese Medical Association. All rights reserved.”
“Background:

The benefits of primary prophylactic implantable cardioverter-defibrillators (ICDs) are actually debated, as some drawbacks become more apparent and as the natural history of cardiac disease seems to improve. Therefore, contemporary follow-up data of non-trial populations treated according to current guidelines remain necessary. The aim of this study was to evaluate mortality and the occurrence of ICD interventions in patients with coronary artery disease (CAD) and dilated cardiomyopathy (DCM) who received in the recent era a primary prophylactic ICD without resynchronization therapy.

Hypothesis: Survival and event-free rates from appropriate ICD therapy are different between ischemic

and nonischemic ICD patients.

Methods: Prospective cohort study of 427 consecutive primary prevention ICD patients with ischemic or nonischemic heart disease, excluding patients with resynchronization.

Results: Ischemic heart disease was present in 290 patients (68%), nonischemic heart disease in 137 VX-680 chemical structure patients (32%). During a median follow-up of 31 months (interquartile range [IQR] 15-45 months), 30 patients (7%) died. Mortality was not different in both disease categories. The incidence of appropriate ICD interventions was similar in CAD and DCM (23% vs 21%). Appropriate ICD intervention occurred

more frequently in patients with atrial fibrillation (29% vs 19%). Inappropriate ICD intervention occurred in 11% of patients.

Conclusions: The clinical course selleck inhibitor of ischemic and nonischemic heart disease patients treated with a primary prophylactic ICD is similar with respect to mortality and to appropriate and inappropriate ICD interventions, in spite of a younger age at baseline of the DCM patients.”
“Background. Few cases of Fabry disease, an X-linked lysosomal storage disorder, complicating pregnancy are reported.

Case. A 36-year-old primigravida with known Fabry disease manifest with acroparesthesias, tinnitus, and hearing loss delivered a healthy unaffected infant at term.

Conclusion. A symptomatic Fabry carrier may experience an otherwise uncomplicated pregnancy in the absence of vital organ involvement.”
“Objectives. To assess the relationship between season of birth and presence of asthma and allergy in preteen, low-income, African American children. Methods. The study consisted of a self-administered survey followed by telephone interviews of parents of children attending 19 middle schools in Detroit, Michigan.

Plants also depleted find more sucrose from

the surrounding media, although a portion of this disaccharide that was hydrolysed into fructose and glucose by putative cell wall invertase activity remained in the media. The delta(13)C in plant dry masses harvested from sugar treatments were all close to -18 parts per thousand, indicating that 25-39% of total plant carbon was from C3 photosynthesis (delta(13)C=-29 parts per thousand) and 61-75% was from uptake of exogenous sugars (delta(13)C=-11 parts per thousand). Carbon-use efficiency (i.e. carbon accumulated/carbon depleted) was significantly improved when plants had a blend of exogenous sugars available compared with plants grown in a single hexose alone. Plants avoided complete down-regulation of photosynthesis even though a large excess of exogenous carbon fluxed through their cells.”
“Study Design. Prospective case series.

Objective. To examine spinal stiffness in patients with low back pain (LBP) receiving spinal manipulative

therapy (SMT), evaluate associations between stiffness characteristics and clinical outcome, and explore a multivariate model of SMT mechanisms as related to effects on stiffness, lumbar multifidus (LM) recruitment, and status on a clinical prediction rule (CPR) for SMT outcomes.

Summary of Background Data. Mechanisms underlying the clinical effects of SMT are poorly understood. Many explanations have been proposed, but few studies have related potential mechanisms to clinical outcomes or considered multiple mechanisms concurrently.

Methods. Patients selleck chemicals llc with LBP were treated with two SMT sessions over 1 week. CPR status was assessed at baseline. Clinical outcome was based

on the Oswestry disability index (ODI). Mechanized indentation measures of spinal stiffness and ultrasonic measures of LM recruitment were taken before and after each SMT, and after 1 week. Global and terminal stiffness were calculated. Multivariate regression was used to evaluate the relationship between stiffness variables and percentage ODI improvement. Zero-order correlations among stiffness Dinaciclib datasheet variables, LM recruitment changes, CPR status, and clinical outcome were examined. A path analysis was used to evaluate a multivariate model of SMT effects.

Results. Forty-eight patients (54% women) had complete stiffness data. Significant immediate decreases in global and terminal stiffness occurred post-SMT regardless of outcome. ODI improvement was related to greater immediate decrease in global stiffness (P = 0.025), and less initial terminal stiffness (P = 0.01). Zero-order correlations and path analysis supported a multivariate model suggesting that clinical outcome of SMT is mediated by improvements in LM recruitment and immediate decrease in global stiffness. Initial terminal stiffness and CPR status may relate to outcome though their relationship with LM recruitment.

Conclusion.

3%; p = 0.009) but not in the placebo group (-16.4%; p = 0.32) Conclusion: Treatment for 8 weeks with omega-3 fatty acids resulted in a significant percentage reduction of CRP levels as compared with baseline, a finding not seen with placebo.”
“Coevolution can be seen as the interdependency between

evolutionary histories. In the context of protein evolution, functional correlation proteins are ever-present coordinated evolutionary characters without disruption of organismal integrity. As to complex system, Lapatinib molecular weight there are two forms of proteine-protein interactions in vivo, which refer to inter-complex interaction and intra-complex interaction. In this paper, we studied the difference of coevolution characters between inter-complex interaction and intra-complex interaction using “”Mirror tree”" method on the respiratory chain (RC) proteins. We divided the correlation coefficients of every pairwise RC proteins into two groups corresponding to the binary proteine-protein interaction in intra-complex and the binary proteine-protein interaction in inter-complex, respectively. A dramatical discrepancy is detected between the coevolution characters of the two sets of protein interactions (Wilcoxon test, p-value 4.4 x 10(-6)).

Our finding reveals some critical information on coevolutionary study and assists the mechanical investigation of proteine-protein interaction. Furthermore, the results also provide some unique clue for supramolecular organization of protein complexes in the mitochondrial inner membrane. More detailed click here ACY-738 cost binding sites map and genome information of nuclear encoded RC proteins will be extraordinary valuable for the further mitochondria dynamics study.”
“Objective. Tooth autotransplantation is a useful surgical method to replace a nonrestorable tooth. We reported our experiences in the replacement of mandibular nonrestorable molars by immediate autotransplantation in a Chinese population.

Study design. Thirty-five mandibular third molars with open or closed apices from 34 patients were autotransplanted into the same or contralateral

fresh recipient sites immediately after the extraction of the nonrestorable mandibular molars. Root canal treatment was routinely performed in the closed-apical molars within 1 month after surgery. Clinical and radiographic examination of the transplanted donor molars was done after surgery.

Results. Two teeth were been extracted for progressive root resorption. The remaining 33 autotransplanted teeth were asymptomatic and functioning after a mean follow-up period of 5.2 years. No infection, ankylosis, loss of the transplants, or root resorption was noted in the remaining autotransplanted teeth.

Conclusion. Immediate autotransplantation of the mandibular third molar is a reasonable and alternative treatment to replace a nonrestorable tooth in China.

5-5.0 sec), the number of sequential tine extensions (2-7 cm), and duration of application (4-12 minutes) for final two to three tine extensions. Optimal parameters to achieve 5-7 cm of

coagulation were compared with recommended algorithms. Optimal settings for 5- and 6-cm final tine extensions were confirmed in in vivo perfused bovine liver (n = 14). Multivariate analysis of variance and/or paired t tests were used.

Results: Mean RF ablation zones of 5.1 cm +/- 0.2 ( standard deviation), 6.3 cm +/- 0.4, and 7 cm +/- 0.3 were achieved with 5-, 6-, and 7-cm final tine extensions in a mean of 19.5 min +/- 0.5, 27.9 min +/- 6, and 37.1 min +/- 2.3, respectively, at optimal settings. With these algorithms, size https://www.selleckchem.com/products/mln-4924.html of ablation at 6- and 7-cm tine extension significantly increased from mean of 5.4 cm +/- 0.4 and 6.1 cm +/- 0.6 (manufacturer’s algorithms) (P < .05, both comparisons); two recommended tine extensions were eliminated. In vivo confirmation produced mean diameter in specified time: 5.5 cm +/- 0.4 in 18.5 min +/- 0.5 (5-cm extensions) and 5.7 cm +/- 0.2 in 21.2 min +/- 0.6 (6-cm extensions).

Conclusion: Large zones of coagulation of 5-7 cm can be created with optimized RF algorithms that help reduce number of tine extensions compared with manufacturer’s recommendations.

Such algorithms are Blasticidin S likely to facilitate the utility of these devices for RF ablation of focal tumors in clinical practice.”
“Alcohol drinking and hepatitis C virus (HCV) infection frequently coexist in patients with chronic liver disease. There is limited information, however, about the impact of alcohol on host cell innate immunity and full cycle replication of HCV. This study investigated whether alcohol impairs the intracellular innate immunity in human hepatocytes, promoting HCV infection and replication. Alcohol

AZD9291 cell line treatment of human hepatocytes before, during and after viral infection significantly enhanced full cycle HCV replication. Alcohol suppressed intracellular expression of type I interferons (IFN-alpha/beta) in human hepatocytes. Investigation of the mechanisms responsible for the alcohol action revealed that alcohol inhibited the expression of the IFN regulatory factors (IRF-5 and IRF-7), and signal transducer and activator of transcription (STAT-1 and STAT-2), the key positive regulators in type I IFN signaling pathway. In addition, alcohol induced the expression of suppressors of cytokine signaling (SOCS-2 and SOCS-3), the key negative regulators of IFN-alpha/beta expression. These in vitro findings suggest that alcohol, through modulating the expression of key regulators in IFN signaling pathway, inhibits type I IFN-based intracellular innate immunity in hepatocytes, which may contribute to the chronicity of HCV infection and the poor efficacy of IFN-alpha-based therapy. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

Post hoc analyses by gender suggested a lower minimum effective dose for women. Desmopressin was generally well tolerated. Reductions in serum sodium to < 125 mmol/L in Cediranib chemical structure six women (taking > 25 mg desmopressin) and two men (aged 67 and 82) taking 100 mg, support lower and gender-specific dosing to reduce

the small but clinically significant risk of hyponatraemia. Each void reduced/hour of sleep gained was associated with significant improvements in QoL. Conclusions: Desmopressin orally disintegrating tablet is an effective and well-tolerated treatment for patients with nocturia. Further exploration of the lower dose range is warranted. Neurourol. Urodynam. 31: 441-447, 2012.

(C) 2012 Wiley Periodicals, Inc.”
“Several studies conducted in the USA have demonstrated that the effectiveness of bariatric surgery differs between patients from African and European origin. However, little is known Vorinostat order on differences in outcomes after bariatric surgery between individuals from other ethnic backgrounds. In this retrospective study, we found that, in terms of weight loss, gastric bypass surgery is less effective in African, South Asian, Turkish and Moroccan patients than in their ethnic Dutch counterparts. Our results underscore that ethnic differences in the effectiveness of bariatric surgery are not limited to those between patients of African and European origin, but extend to other minority groups

as well. Therefore, it is important that prospective studies both determine ethnic differences in weight loss-related improvement of co-morbidities and elucidate the exact reasons for these ethnic disparities.”
“An almost ubiquitous occurrence of imposex and butyltins in the molluscs from US Virgin Islands gives evidence to a widespread contamination with the antifouling agent tributyltin (TBT), which most likely is related DMXAA to a relatively intense ship traffic. Three different muricid neogastropod species Thais deltoidea, Thais rustica and Purpura patula all seem to have potential as suitable and sensitive bioindicators for assessing levels and effects of TBT pollution in coastal areas including coral reefs in the Caribbean Sea. However, considerable interspecies differences in especially accumulation potential of butyltins were seen in this study. Furthermore, a high accumulation potential of TBT in the edible gastropod West Indian topshell (Cittarium pica) was found, despite that no signs of imposex were observed in this archaeogastropod species. (C) 2009 Elsevier Ltd. All rights reserved.”
“Aims To evaluate the utility of the International Prostate Symptom Score (IPSS) and the LUTS Tool when assessing lower urinary tract symptoms (LUTS). Secondary objectives were to examine associations of LUTS and treatment seeking.

“
“Obesity constitutes a growing health problem, and surgical treatment of severe obesity is increasingly used. Nutrient deficiencies are common following bariatric surgery and the evidence indicates a progressive increase in the incidence and Pevonedistat nmr severity of the deficiency of certain vitamins and related clinical conditions. Because of the potential role of carotenoids in disease prevention, our aim was to assess the carotenoid status in candidates

for obesity surgery and the time-course changes following two bariatric procedures.

Seventy-five candidates for bariatric surgery (17 men, 58 women; age 43 +/- 10 years) and a total of 362 serum samples after obesity surgery (i.e., Roux-en-Y gastric bypass (n = 187) and biliopancreatic

diversion (n = 175)) were consecutively collected and assessed. Retinol, alpha- and gamma-tocopherol, 25-OH-vitamin D3, lutein, zeaxanthin, alpha- and beta-cryptoxanthin, lycopene (trans and cis), alpha- and beta-carotene (trans and cis) were analyzed by high-performance liquid chromatography.

Mean serum levels of carotenoids in candidates for obesity surgery were within the reference values reported in controls and seasonal 3-deazaneplanocin A purchase variations were present in several analytes. After surgery, and regardless of the type of intervention, all serum carotenoids dropped following first-order kinetics. Cis/trans ratio of lycopene and beta-carotene did not change after surgery, over the time or between surgical procedures. On a long-term, serum carotenoids were at or below fifth percentile of reference groups.

The chronic low levels of carotenoids in these patients compromise their availability Lazertinib purchase to tissues, constituting an additional risk factor for other clinical conditions. Dietary advice on carotenoid-rich, fortified foods or supplements should be also evaluated in these patients.”
“In recent decades, in the US and in Western and Northern Europe, there has been a significant increase in the prevalence of atopic allergic disease. Although that increase may now be slowing, or have already reached a plateau, there remains considerable interest

in the factor or factors that may have caused this increased susceptibility to allergy and asthma. Certainly, the changes recorded have been too rapid to implicate a change in the gene pool, and for that reason attention has focused on the possible impact of environmental, dietary, and lifestyle factors. Although the hygiene hypothesis proposes that increased susceptibility to allergic sensitization is associated with changes in childhood exposure pathogenic microorganisms, other factors have been considered also. Among these is exposure to chemicals and atmospheric pollutants. There is some evidence that exposure to certain chemicals may elicit or exacerbate respiratory reactions in those who are already sensitized, or who already have existing airway disease.