C3-containing IgE immune complexes in asthmatic patients.

Higher levels of IgE-containing immune complexes (IC) have been reported in sera from patients with allergic diseases than in sera from controls. To evaluate the possibility of an IC-mediated mechanism in the pathogenesis of bronchial asthma, we measured circulating C3-containing IgE IC (C3-IgE IC) using anti-C3 ELISA from 20 house dust mite (HDM)-sensitive asthmatics, 20 non-atopic asthmatics, and 14 non-atopic controls. C3-IgE IC levels were significantly higher in HDM-sensitive asthmatics (mean +/- S.D.: 12.2 +/- 7.8 AU/ml) than in non-atopic asthmatics (6.5 +/- 7.5 AU/ml) or controls (5.8 +/- 4.4 AU/ml). C3-IgE IC levels were significantly correlated with HDM-specific IgE levels (r = 0.50, p < 0.05), but not with total IgE levels (r = 0.36, p > 0.05) in HDM-sensitive atopic asthmatics. C3-IgE IC levels in sera did not significantly change during HDM-bronchoprovocation test in six HDM-sensitive asthmatics who showed positive reaction. Part of C3-IgE IC could be precipitated by protein G coupled beads. In conclusion, C3-IgE IC levels were elevated in sera from HDM-sensitive asthmatics; moreover IgG antibodies might be a component of C3-IgE IC. Our results suggest that an IgE IC-mediated mechanism could be involved in the pathogenesis of atopic asthma.     

Cytokine production by T helper cell subpopulations during prolonged in vitro stimulation.

In man, CD4+ T cells can be divided into phenotypically distinguishable subsets with different function whereas CD4+ T cells with the opposite pheno-CD45RO and low levels of CD45RA antigen provide help for mitogen-induced immunoglobulin production whereas CD4+ cells with the opposite phenotype suppress immunoglobulin production. However, studies examining cytokine production by phenotypically defined CD4+ T cell subsets have led to different conclusions. Further, very few studies have examined cytokine production by freshly isolated CD4+ T cell subsets during extended culture periods. Thus, we examined the production of several cytokines (at various time points) by CD4+ T cell subsets that were isolated in several ways, and stimulated with PWM, Con A, and PHA in a well-defined serum-free culture system. We found that CD4+, CD45RA- (or CD45RO+) T cells consistently produced the most IL-2, IFN-gamma, and TNF-alpha after mitogen stimulation for 2 days. PWM induced the largest quantities of each cytokine, although a similar pattern of production was observed in response to Con A and PHA. We were unable to detect IL-4 production by mononuclear cells and CD4+ T cell subsets suggesting that, if it is produced at all, IL-4 is produced in extremely small quantities. When the culture period of initially CD45RO- T cells was extended beyond 2 days, the culture supernatant contained increased quantities of each cytokine and the cells in the culture had an increased number of cells expressing CD45RO antigen. Together, these data indicate that CD4, CD45RA- (or CD45RO+) T cells in peripheral blood are the major producers of IL-2, IFN-gamma, and TNF-alpha following short-term mitogen stimulation, and that phenotypically defined peripheral blood T cell subsets do not maintain a distinct pattern of cytokines during extended culture periods.     

Dimeric cinchona ammonium salts with benzophenone linkers: enantioselective phase transfer catalysts for the synthesis of α-amino acids

Chiral phase transfer catalysts of dimeric cinchona ammonium salts linked with a benzophenone bridge showed high enantioselectivity in the α-alkylation of a glycinate ester under mild industry-applicable conditions: 0.5 mol% PTC and near equivalents of alkyl halide. A dual function of the dimeric quinuclidiniums was proposed for the high efficiency.

Novel cinchona-alkaloid derived dimeric phase transfer catalysts (PTC) with benzophenone linkers and their α-alkylation of glycinate esters has been presented.

Since cinchona alkaloids were transformed to asymmetric quaternary quinuclidinium salts with benzyl halides and were used as a phase-transfer catalyst (PTC) (1) by Dolling¹ and O''Donnell,² cinchona alkaloids have been widely utilized as chiral templates for phase-transfer catalysis.³ (Scheme 1) These organic PTCs can be easily prepared from natural and low cost chiral cinchona alkaloids in a few synthetic steps and they are stable and facile under normal reaction conditions in water. Later N-9-anthracenylmethyl quinuclidinium salt PTC (2) was introduced and showed high enantioselectivity for the alkylation of the protected glycine tert-butyl ester.⁴ Quinuclidinium PTCs with each pseudo-enantiomeric cinchona alkaloids, such as (−)-cinchonidine and (+)-cinchonine, show enantiomeric selectivity each other, and have been successfully applied in various asymmetric organic synthesis including α-alkyl glycine derivatives synthesis.³Open in a separate windowScheme 1Representative cinchona-derived PTCs.Enantioselectivity in the alkylation of glycine esters has been probed by several experimental trials. Crystallographic study of the p-nitrophenoxide salt of PTC 2 showed that N-anthracenylmethy moiety of 2 is located in staggered position between the C^c and the C^d,^4a which provides more hindered spaces around the C^b–C^c–C^d face (F4) around the ammonium.⁵ The C^a–C^b–C^d face (F2) is blocked by O-allyl group and the C^a–C^c–C^d face (F3) are covered by bicyclic ring, but the C^a–C^b–C^c face (F1) is less hindered. Therefore, anionic glycinate derivatives could approach toward the F1. Enolates of glycine esters would form tight ionic complexes with the ammonium nitrogen on the F1 face of PTC 2, and the alkylation with alkyl halides could follow along the direction of less hindered side of the si/re-face of the enolates.^4aNOE correlations study of PTC 2 with borohydride ion⁶ indicated the borohydride occupies the F1 face of PTC 2. Computational simulation⁷ also described the stable transition states where an enolate locates on the F1 face.Dimeric cinchona-derived PTCs linked by either benzene or naphthalene ligand have been introduced by Park et al.^8a–c Among ortho, meta and para-connected PTCs, the meta-disubstituted phenyl PTC 3a or 2,7-disubstituted naphthyl PTC 3b showed highly improved catalytic effects compared to monomeric PTC 2, such as lower dosage of catalyst (1–5 mol%) and high enantioselectivity. Role of additional quinuclidinium was thought to be a steric blocker which could increase the stereoselectivity of the enolate complex on the F1 face.Other dimeric cinchona alkaloid PTCs were also developed with various linkers, such as 9,10-dimethylanthracenyl,⁹ biphenyl, alkenyl,¹⁰ macrocyclic amine and calixarene,¹¹ and their enantioselectivities were equal or lower than those of monomeric PTCs. Some dimeric PTCs were converted to ionic polymers by replacing bromides to a disufonate anion without loss of reactivity and enantioselectivity.¹²Alkylation of tert-butyl glycinate ester was performed with 1–10 mol% of PTC 1–3 and excess 5 equivalents of alkyl halide at 0 to −78 °C. These catalytic conditions are still to be improved for practical application; low mol% of PTC, near equimolar amount of alkyl halides and ambient temperature. Hence we investigated dimeric PTCs with various linkers for facile catalytic condition. Here we introduce new dimeric cinchona PTCs with a benzophenone linker and their application in asymmetric alkylation of glycine derivatives.Monomeric PTC 4p, N-(4-benzoylbenzyl)-O(9)-allylcinchonidium bromide, which has a benzoyl benzyl at N(1), was synthesized from 4-bromomethyl-benzophenone and (−)-cinchonidine. (Scheme 2) Dimeric cinchona-based quarternay ammonium salts (PTC 5–6) were synthesized from meta/para-di(bromomethyl) benzophenone¹³ and two equivalent cinchona alkaloids. Coupling reaction of the di(bromomethyl)benzophenone and (−)-cinchonidine or (+)-cinchonine in EtOH/DMF/CHCl₃ (5 : 6 : 2)⁸ for 5 h at 100 °C and the O(9)-allylation with allyl bromide gave the dimeric quarternary salts, bis(4-(O(9)-allyl-cinchonidium-N-methyl)phenyl) methanone dibromide (5) and bis(4-(O(9)-allyl-cinchonium-N-methyl)phenyl) methanone dibromide (6), respectively, in good yields.^‡Open in a separate windowScheme 2Monomeric and dimeric cinchona-PTC with a benzophenone bridge.Enantioselective PTC 4–6 system was applied in the alkylation of N-(diphenylmethylene)glycine tert-butyl ester (7) to the α-alkylated glycinate (8) under the condition of 0.5–1.0 mol% catalysts and 1.2 equivalent alkyl halides. We also explored the variation of enantioselectivity depending on the various positions of dimeric cinchonidium at benzophenone; 5pp, 5mp and 5mm.Monomeric PTC 4p showed enantioselectivity of 87% ee (S) at 25 °C (2 Geometric difference between PTC 1 and 4p is the extra p-benzoyl substituent on N-benzyl. Apparently the p-benzoyl moiety gives no big enhancement in enantioselectivity of 4p.Catalytic phase-transfer benzylation of 7 with monomeric and dimeric cinchona-based catalysts (4–6)^a

The relationship between smartphone use and subjective musculoskeletal symptoms and university students

[Purpose] The purpose of this study was to investigate the use of smartphones by university students in selected areas, their musculoskeletal symptoms, and the associated hazard ratio. [Subjects and Methods] This involved the completion of a self-administered questionnaire by dental hygiene students in Seoul, Gyeonggido, and Gyeongsangbukdo. The 292 completed copies of the questionnaire were then analyzed. [Results] The most painful body regions after the use of smartphones were found to be the shoulders and neck. In the musculoskeletal system, back pain was found to have a positive correlation with the size of the smartphone’s liquid crystal display (LCD) screen, and pain in legs and feet were found to have a negative correlation with the length of time that the smartphone was used. As a result, it was revealed that the use of a smartphone was correlated with musculoskeletal symptoms. [Conclusion] Therefore, in today’s environment, where the use of smartphones is on the rise, it is necessary to improve the ways that they are used and to develop a preventive program to alleviate the symptoms of musculoskeletal damage.Key words: Smartphone, Musculoskeletal symptoms, Prevent     

The distance between the carina and the distal margin of the right upper lobe orifice measured by computerised tomography as a guide to right‐sided double‐lumen endobronchial tube use

Our hypothesis was that the incidence of malposition of a right‐sided double‐lumen endobronchial tube and right upper lobe collapse may increase when the distance between the carina and the distal margin of the right upper lobe orifice is less than 23 mm, measured from a computerised tomography scan. A total of 76 patients undergoing left‐sided thoracic surgery were enrolled. Patients with a measured distance of < 23 mm (n = 38) were compared with age‐, sex‐ and body mass index‐matched patients with a distance ≥ 23 mm (n = 38). Right‐sided double‐lumen endobronchial tubes were used universally. We monitored endobronchial tube malposition and incidence of right upper lobe collapse throughout surgery. There was a significantly higher incidence of bronchial cuff herniation in patients with a distance < 23 mm in both the supine position and the lateral decubitus position (p < 0.001). The incidence of intra‐operative malposition in the < 23 mm group was also significantly higher than in the ≥ 23 mm group (31 (82%) vs 8 (21%), respectively, p < 0.001). Right upper lobe collapse was detected postoperatively in five patients (13%) in the distance < 23 mm group, compared to none in the ≥ 23 mm group. We recommend that the distance between the carina and the distal margin of the right upper lobe bronchus should be routinely measured on the pre‐operative computerised tomography scan, and if it is < 23 mm, consideration should be given to using a left‐sided endobronchial double‐lumen tube in preference to a right‐sided one.     

The diagnostic value of fine needle aspiration in parotid lumps

Introduction

Fine needle aspiration (FNA) is a safe and quick method of diagnosing superficial lumps, which aids preoperative planning. However, FNA of the parotid gland has not gained the widespread acceptance noted in other head and neck lumps. The aim of this study was to determine the ability of FNA of the parotid gland to differentiate benign and malignant disease, and to determine the impact on surgical outcome.

Methods

A retrospective analysis of 201 consecutive parotid operations with preoperative FNA in a large district hospital in the UK was performed. The diagnostic characteristics were calculated for benign and malignant disease, and the impact on surgical procedure was determined.

Results

In identifying benign disease, FNA has a sensitivity of 85% and a specificity of 76%. In detecting malignant disease, FNA has a sensitivity and specificity of 52% and 92% respectively. A false positive on FNA was associated with a higher incidence of neck dissection.

Conclusions

FNA is a useful diagnostic test. However, owing to low sensitivity, it is necessary to interpret it in the context of all other clinical information.