Theory of self-oscillation and mode locking in a longitudinal photoacoustic resonator.

The wave equation for pressure that governs generation of the photoacoustic effect possesses a forcing term proportional to the time derivative of the energy delivered to the gas per unit volume and time. A positive pressure fluctuation, with its accompanying density increase, thus increases the optical absorption and provides a positive feedback mechanism for sound generation. A theory for self-oscillation in a one-dimensional resonator is given. Expressions for the photoacoustic pressure are derived for the cases of highly and weakly absorbing gases that indicate mode-locked sound generation. Experiments with CO2 lasers are reported where evidence of the self-generation effect was sought.

Diagnostic value of the serum-specific IgE ratio of ω-5 gliadin to wheat in adult patients with wheat-induced anaphylaxis.

BACKGROUND: Wheat is an important food allergen associated with severe allergic reactions, including wheat-dependent exercise-induced anaphylaxis (WDEIA) and wheat-induced anaphylaxis (WIA). To diagnose WDEIA, an exercise challenge test following wheat ingestion is performed, which is time-consuming and unsafe. The compound ω-5 gliadin has been identified as a major allergen for WDEIA and WIA. We evaluated the diagnostic value of serum immunoglobulin E (IgE) ratios of ω-5 gliadin to wheat in adult patients with WDEIA or WIA. METHODS: In total, 27 patients were enrolled and classified into 2 groups according to the severity of their allergic reactions to wheat. Serum IgE, specific to wheat and ω-5 gliadin, was measured using the ImmunoCAP system. To evaluate the diagnostic value, receiver operator characteristic curves were produced. RESULTS: Group 1 included 17 patients with a history of anaphylaxis and group 2 included 10 patients having urticaria or atopic dermatitis. Serum IgE specific to wheat was increased in 47% of group 1 and 100% of group 2. However, all patients in group 1 had high serum IgE specific to ω-5 gliadin, whereas only 20% of group 2 showed increased levels. To identify a better diagnostic value, the log-transformed IgE ratio of ω-5 gliadin to wheat was calculated, with the cutoff value at 0.3. Based on these criteria, we found 100% sensitivity and specificity. CONCLUSIONS: This study confirms that the serum IgE ratio of ω-5 gliadin to wheat may be a useful marker for the diagnosis of WDEIA and WIA.

Effects of exothermic chemical reaction on the photoacoustic effect from particulate suspensions.

Irradiation of chemically reactive particulate suspensions by high power, pulsed laser radiation initiates reactions at the sites of the particles so that besides the absorbed optical energy, chemical energy is liberated. In addition to the release of chemical energy, chemical reaction can result in gas production both of which result in enhancement in the amplitude of the photoacoustic effect. Here we report photoacoustic and transient grating experiments with colloidal C in mixtures of H(2)O(2) with H(2)O. The inclusion of H(2)O(2) in an aqueous C suspension changes the normally endothermic reaction of C with H(2)O into the highly exothermic reaction of C with H(2)O(2) leading to both an enhanced photoacoustic effect and an increase in light emission from the suspension. As well, laser-initiated exothermic reactions in suspensions of C with CH(3)NO(2) and particulate Hg(CNO)(2) in H(2)O are shown to result in greatly enhanced photoacoustic signal amplitudes.

Association of ß2-adrenergic receptor polymorphism with work-related symptoms in workers exposed to wheat flour.

PURPOSE: Our previous study indicated that the presence of wheat-specific IgG1 and IgG4 antibodies was associated with work-related symptoms in workers exposed to wheat flour. We performed this study to investigate the genetic polymorphisms of ß2-adrenergic receptors and wheat-specific antibodies in association with the clinical parameters of baker's asthma. MATERIALS AND METHODS: In total, 379 subjects working in a single industrial bakery were enrolled in this study. The skin prick test was performed with common inhalant allergens and wheat flour extract. The presence of serum- specific IgE, IgG1, and IgG4 antibodies to wheat flour were determined by ELISA. Whole blood samples were obtained for genotype analysis. Subjects were genotyped with regard to five candidate single nucleotide polymorphisms (SNPs) of the ß2-adrenergic receptor gene (ADRB2; -47 T>C, 46 A>G, 79 C>G, 252 G>A, and 523 C>A) using a single-base extension method. RESULTS: No significant associations were observed between the genotype/allele frequencies of any of the SNPs tested and any clinical parameters. The haplotype of ADRB2 (GAA composed of 46 A>G, 252 G>A, and 523 C>A) was significantly associated with work-related symptoms (p<0.05). Moreover, in subjects with the AG or GG genotype at 46 A>G and haplotype [GAA] of ADRB2, the prevalence rates of wheat-specific IgG1 antibodies and lower respiratory symptoms increased significantly with exposure intensity (both p<0.05). CONCLUSION: The findings of the present study suggest that ADRB2 genetic polymorphism may contribute to the development of work-related symptoms in workers exposed to wheat flour, which can lead to baker's asthma.

Comparison of ultrasonic distillation to sparging of liquid mixtures.

The application of intense ultrasound to a liquid-gas interface results in the formation of an ultrasonic fountain and generates both mist and vapor from the liquid. Here, the composition of the vapor and aerosol above an ultrasonic fountain is determined as a function of irradiation time and compared with the results of sparging for five different solutions. The experimental apparatus for determining the efficiency of separation consists of a glass vessel containing a piezoelectric transducer driven at either 1.65 or 2.40 MHz. Dry nitrogen is passed over the ultrasonic fountain to remove the vapor and aerosol. The composition of the liquid solutions are recorded as a function of irradiation time using gas chromatography, refractive index measurement, nuclear magnetic resonance, or spectrophotometry. Data are presented for ethanol-water and ethyl acetate-ethanol solutions, cobalt chloride in water, colloidal silica, and colloidal gold. The experiments show that ultrasonic distillation produces separations that are somewhat less complete than what is obtained using sparging.

Immunoglobulin G subclass deficiency is the major phenotype of primary immunodeficiency in a Korean adult cohort.

Primary immunodeficiency disease (PID) is a rare disorder in adults. Most often, serious forms are detected during infancy or childhood. However, mild forms of PID may not be diagnosed until later in life, and some types of humoral immunodeficiency may occur in adulthood. The purpose of this study was to identify clinical features of PID in Korean adults. A retrospective study was performed on 55 adult patients who were diagnosed as PID between January 1998 and January 2009 at a single tertiary medical center in Korea. IgG subclass deficiency was the most common phenotype (67%, 37/55), followed by total IgG deficiency (20%, 11/55), IgM deficiency (7%, 4/55), common variable immunodeficiency (2%, 1/55), and X-linked agammaglobulinemia (2%, 1/55). IgG3 and IgG4 were the most affected subclasses. Upper and lower respiratory tract infections (76%) were the most frequently observed symptoms, followed by multiple site infection (11%), urinary tract infection, and colitis. Bronchial asthma, rhinitis, and several autoimmune diseases were common associated diseases. IgG and IgG subclass deficiency should be considered in adult patients presenting with recurrent upper and lower respiratory infections, particularly in those with respiratory allergies or autoimmune diseases.

Clinical and radiographic features of adult-onset ankylosing spondylitis in Korean patients: comparisons between males and females.

The objective of this study was to investigate clinical and radiographic features and gender differences in Korean patients with adult-onset ankylosing spondylitis. Multicenter cross-sectional studies were conducted in the rheumatology clinics of 13 Korean tertiary referral hospitals. All patients had a confirmed diagnosis of ankylosing spondylitis according to the modified New York criteria. Clinical, laboratory, and radiographic features were evaluated and disease activities were assessed using the Bath ankylosing spondylitis disease activity index. Five hundred and five patients were recruited. The male to female ratio was 6.1:1. Average age at symptom onset was 25.4+/-8.9 yr and average disease duration was 9.6+/-6.8 yr. Males manifested symptoms at a significantly earlier age. HLA-B27 was more frequently positive in males. Hips were more commonly affected in males, and knees in females. When spinal mobility was measured using tragus-to-wall distance and the modified Schober's test, females had significantly better results. Radiographic spinal changes, including bamboo spine and syndesmophytes, were more common in males after adjustment of confounding factors. In conclusion, we observed significant gender differences in radiographic spinal involvement as well as other clinical manifestations among Korea patients with adult-onset ankylosing spondylitis. These findings may influence the timing of the diagnosis and the choice of treatment.

An antinuclear antibody-negative patient with lupus nephritis.

Systemic lupus erythematosus (SLE) is a typical autoimmune disease that's characterized by various autoantibodies to nuclear and cytoplasmic antigens. The presence of antinuclear antibodies (ANA) in serum is generally considered a decisive diagnostic sign of SLE. However, a small subset of SLE patients who had the typical clinical features of SLE was reported to show persistently negative ANA tests. Our report describes a 16-yr-old female who presented with the clinical manifestations of SLE such as malar rash, photosensitivity, arthritis, lymphopenia, pericarditis and proteinuria. The serum autoantibodies were all negative and renal biopsy showed that the histopathological changes of immune complex mediated the focal segmental necrotizing glomerulonephritis with crescent formation. She was treated with monthly pulse cyclophosphamide along with corticosteroids. During the 2-yr follow-up period, the proteinuria was markedly decreased and all of the ANA and anti-double stranded DNA antibody tests were negative. This case suggests that ANA may not be required in the pathogenesis of lupus nephritis.

Serum ferritin and transferrin levels as serologic markers of methylene diphenyl diisocyanate-induced occupational asthma.

BACKGROUND: Although methylene diphenyl diisocyanate (MDI) may induce occupational asthma in the workplace, the pathogenic mechanisms are unclear. OBJECTIVES: By using bronchoalveolar lavage fluid, we sought to identify proteins that were differentially expressed between subjects with MDI-induced occupational asthma (MDI-OA) and asymptomatic exposed controls (AECs). METHODS: To find proteins that were differentially expressed between the MDI-OA and AEC groups, 2-dimensional electrophoresis was performed by using bronchoalveolar lavage fluid obtained from subjects after MDI-specific inhalation challenge. The selected protein spots were then identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The clinical relevance of the differentially expressed spots was compared by ELISA using sera from the MDI-OA/eosinophilic bronchitis, AEC, and unexposed healthy control groups. Receiver operating characteristic curves were then plotted, and the sensitivity and specificity were determined. RESULTS: Twenty-three protein spots were identified that distinguished the subjects with MDI-OA from those in the AEC group. Among them, ferritin expression was downregulated whereas transferrin expression was upregulated in subjects with MDI-OA compared with AEC; these results were validated by ELISA using sera from the MDI-OA/EB and AEC groups. To identify subjects with MDI-OA, the optimal serum cutoff levels were 69.84 ng/mL for ferritin and 2.48 microg/mL for transferrin. When these 2 parameters were combined, the sensitivity was 71.43% and the specificity was 85.71%. CONCLUSION: Serum ferritin and transferrin levels are associated with the phenotype of MDI-OA.

Association of specific IgE to staphylococcal superantigens with the phenotype of chronic urticaria.

It has been well established that bacterial superantigens lead to the induction and aggravation of chronic inflammatory skin diseases. We investigated the clinical significance of serum specific immunoglobulin E (lgE) to the staphylococcal superantigens staphylococcal enterotoxin A (SEA), staphylococcal enterotoxin B (SEB), and toxic shock syndrome toxin (TSST)-1 in patients with chronic urticaria (CU), focusing on the differences in these prevalences between aspirin-intolerant CU (AICU) and aspirin-tolerant CU (ATCU) patients. Aspirin sensitivity was confirmed by oral aspirin provocation test. There were 66 patients AICU and 117 patients ATCU in the study. Serum IgE antibodies specific for SEA, SEB, and TSST-1 were measured by the ImmunoCAP test and the patients were compared with 93 normal controls (NC). The prevalences of serum specific IgE to staphylococcal superantigens were significantly higher in CU than in NC patients (IgE to SEA, 13.7% vs. 5.4%; IgE to SEB, 12.0% vs. 4.3%; IgE to TSST-1, 18.0% vs. 6.5%; p<0.05, respectively). The patients with specific IgE to SEA, SEB, and TSST-1 had higher serum total IgE levels and higher rates of atopy. Significant associations were noted between the prevalence of specific IgE to SEA and SEB and the HLA DQB1*0609 and DRB1*1302 alleles in the AICU group. We confirmed that a sub-population of patients with CU possesses serum IgE antibodies to SEA, SEB, and TSST- 1. Particularly, the IgE immune response to TSST-1 is associated with aspirin sensitivity in CU patients.

Histamine release and inflammatory cell infiltration in airway Mucosa in methylene diphenyl diisocyanate (MDI)-induced occupational asthma.

INTRODUCTION: Although methylene diphenyl diisocyanate (MDI) is widely used in industries, there have been few studies of the pathogenic mechanisms of MDI-induced occupational asthma (MDI-OA). METHODS: We performed immunohistochemical analyses, measured inflammatory mediators and cytokines, and quantified histamine release (HR) from peripheral basophils in MDI-OA patients. Thirteen MDI-exposed workers (five MDI-OA, two MDI-induced esoinophilic bronchitis, and six asymptomatic exposed controls, AEC) were enrolled. RESULTS AND DISCUSSION: Immunochemical analyses indicated significantly increased anti-eosinophilic cationic protein-stained cells in MDI-OA patients as compared with controls (P < 0.05). Sputum eosinophil cationic protein levels were increased after MDI-specific inhalation challenge test in MDI-OA/EB patients (P < 0.02). Sputum eosinophil counts were highly correlated with IL-8 and MMP-9 levels (P < 0.05 and P < 0.01, respectively). Basophil HR was significantly increased in MDI-OA patients after stimulations with anti-IgG4 and MDI-human serum albumin conjugates (both P < 0.05). Eosinophil activation is a major feature of airway inflammation in MDI-OA patients. Increased HR by MDI may contribute to the pathogenic mechanisms of MDI-OA.

Treatment of atopic dermatitis with a combination of allergen-specific immunotherapy and a histamine-immunoglobulin complex.

BACKGROUND: Allergic responses to common environmental agents are believed to be involved in the development of atopic dermatitis, but clinical usefulness of allergen-specific immunotherapy in the treatment of atopic dermatitis is controversial. We performed a pilot study to evaluate the clinical usefulness of combined treatment with allergen-specific immunotherapy and a histamine-immunoglobulin complex in patients with atopic dermatitis. METHODS: Twenty patients with atopic dermatitis and hypersensitivity to house dust mites whose clinical conditions had not been effectively controlled by current standard medical therapies were treated with a combination of allergen-specific immunotherapy using house dust mite extract and a histamine-immunoglobulin complex for 12 months. The primary efficacy outcome was the change in the standardized clinical severity scoring system for atopic dermatitis (SCORAD) values at 6 and 12 months in comparison with the values at baseline. RESULTS: In 18 patients who completed all 12 months of treatment, the SCORAD values significantly decreased from 43.6 +/- 15.9 at baseline to 27.8 +/- 18.3 at 6 months and 18.3 +/- 14.9 at 12 months (Wilcoxon signed-rank test, p < 0.001), and no significant systemic side effects were observed. CONCLUSIONS: In this uncontrolled pilot study, combined treatment with allergen-specific immunotherapy and a histamine-immunoglobulin complex resulted in significant clinical improvements in patients with atopic dermatitis. However, double-blind placebo-controlled studies are necessary to test the clinical usefulness of this modified allergen-specific immunotherapy for atopic dermatitis.

Identification of Dioscorea batatas (sanyak) allergen as an inhalant and oral allergen.

Dioscorea batatas is widely used in Asia as a herbal medicine or food product with potential health benefits. There have been several reports of occupational asthma caused by inhalation of D. batatas dust. However, there has been no report of systemic allergic reactions after oral administration of D. batatas. Two patients with D. batatas allergy were enrolled. One had experienced severe urticaria and angioedema after indigestion, and the other had been exposed to D. batatas dust and was diagnosed as having occupational asthma. Both patients had high serum-specific IgE and IgG4 antibodies to D. batatas. And IgE immunoblot demonstrated that both sera bound to a 27-kDa protein with an IgE-binding motif, which was revealed by 2-D-electrophoresis to have the sequence Asn-Val-Glu-Asp-Glu-Phe-Ser-X-Ile- Glu-Gly-Asn-Pro-X-X-Pro-Glu-Asn-X-Gly (pI 6.40, 6.04). In conclusion, discorin from D. batatas (DB3S) was identified as the major allergen of D. batatas in patients sensitized via an oral or inhalant route.

Prevalence of work-related symptoms and serum-specific antibodies to wheat flour in exposed workers in the bakery industry.

BACKGROUND: Although baker's asthma (BA) is a common occupational asthma, there have been few reports on this disease in Korean subjects. OBJECTIVES: We evaluated the prevalence of serum-specific IgE, IgG1, and IgG4 antibodies in relation to work-related respiratory symptoms in a single industrial bakery. METHODS: Three hundred and ninety-two bakery workers were administered and taken a questionnaire regarding respiratory symptoms. For symptomatic workers, the methacholine bronchial challenge test and specific bronchoprovocation tests with wheat extracts were carried out. Skin prick tests were performed and serum-specific IgE, IgG1, and IgG4 antibodies to wheat flour were detected. The IgE- and IgG4-binding components were identified by immunoblotting. RESULTS: Sixty-seven workers (17.1%) complained of work-related upper and lower respiratory symptoms. The prevalence of BA based on positive bronchoprovocation test results was 1.5%. The sensitization rate to wheat flour was 5.9% by skin prick test and 6.5% by ELISA, and was closely associated with the presence of atopy and work-related lower respiratory symptoms (P<0.001 for both). IgE immunoblotting revealed six major IgE-binding components (27, 31, 36, 43, 54, and 72 kDa). The presence of wheat-specific IgG1 and IgG4 antibodies was found to be significantly associated with exposure intensity (P<0.05 for both). CONCLUSIONS: The overall prevalence of wheat sensitization in a Korean bakery was 5.9%. We confirmed that an IgE-mediated response is the major pathogenic mechanism for the induction of work-related symptoms in wheat-exposed workers. Wheat-specific IgG antibodies may represent current or previous exposure to wheat dust.

Clinical characteristics of lupus myocarditis in Korea.

Clinically important myocarditis is an unusual feature in systemic lupus erythematosus (SLE). We describe the clinical characteristics, management and outcomes of five SLE patients who developed severe left ventricular dysfunction. Four patients were female with mean age of 36.4 years. Three patients had both lupus myocarditis and lupus nephritis. Four patients had raised anti-dsDNA antibody titer and low complement level and two patients had positive IgG anticardiolipin antibody. Three patients were treated by high-dose corticosteroids, one patient by intravenous pulse methylprednisolone, and one patient by intravenous immunoglobulin and pulse cyclophosphamide with high dose corticosteroids. Left ventricular function improved markedly in four patients and all of them had no recurrence of lupus myocarditis up to follow-up of 33 months. However, one patient, who showed no improvement of left ventricular function, was expired due to sudden cardiac arrest. Lupus myocarditis should be treated by immunosuppressive therapy with high-dose corticosteroids and mostly the prognosis might be good with early treatment.

Differential contribution of the CysLTR1 gene in patients with aspirin hypersensitivity.

In this study, we compared the roles of CysLT receptor type 1 (CysLTR1) and leukotriene C4 synthase (LTC4S) gene polymorphisms in two major aspirin-related allergic diseases, aspirin-intolerant asthma (AIA) and aspirin-induced chronic urticaria/angioedema (AICU). CysLTR1-634C>T and LTC4S-444A>C polymorphisms were genotyped and its functional effect on the promoter activity was compared. As in vivo functional study, changes of peripheral mRNA level of CysLTR1 were measured by real-time PCR before and after aspirin challenge. A significant association was found for the CysLTR1 promoter polymorphism and the AIA phenotype compared to AICU (P = 0.015). In U937 cells, the variant genotype reporter construct showed significantly higher promoter activity than the common genotype (P < 0.05). The CysLTR1 mRNA levels increased significantly after aspirin challenge in AIA patients (P = 0.013). In conclusion, the CysLTR1 polymorphism may contribute to develop to the AIA phenotype and be used as a genetic marker for differentiating two major aspirin hypersensitivity phenotypes.

Successful treatment of pediatric systemic polyarteritis nodosa with cholestatic hepatitis.

Polyarteritis nodosa (PAN) is a rare vasculitis in children. We report a case of 5-year-old boy with systemic PAN and cholestatic hepatitis. He had fever, abdominal pain, and gastrointestinal bleeding. Angiography revealed multiple microaneurysms in the renal, hepatic, and superior mesenteric arteries. Clinical manifestations improved slowly after immunosuppressive therapy, but liver enzyme and bilirubin levels elevated gradually. Liver biopsy findings revealed marked centrizonal canalicular cholestasis, bile duct damage, and intact hepatocyte, but there was no evidence of viral hepatitis or vasculitis. Levels of liver enzymes and bilirubin improved after two cycles of cyclophosphamide therapy. We thought that the possible etiology of elevated liver enzyme and bilirubin levels might be a manifestation of PAN.

Excited-state tautomerization dynamics of 7-hydroxyquinoline in beta-cyclodextrin.

The excited-state tautomerization dynamics of 7-hydroxyquinoline encapsulated in beta-cyclodextrin is compared with that in pure water by measuring isotope-dependent fluorescence kinetics as well as absorption and emission spectra. The normal species tautomerizes stepwise via forming anionic intermediate species in both systems. However, the enol-deprotonation time (40 ps in water) becomes as large as 170 ps whereas the imine-protonation time of the anionic intermediate (160 ps in water) becomes as short as 85 ps in beta-cyclodextrin. The slow formation and the fast decay of the anionic species are attributed to the unstability of the charged species in hydrophobic cages. Encapsulation can be utilized to enhance fluorescence enormously and to accelerate selective reactions by retarding other processes.