Search

The value of the gas chromatography (GC) and selected ion flow tube mass spectrometry (SIFT-MS) combination for the analysis of trace gases is demonstrated by the quantification of acetone in air samples using the three precursor ions available to SIFT-MS, viz. H3O+, NO+ and O2+, and by the separation of the isomers 1-propanol and 2-propanol, and their analysis using H3O+ precursor ions. It is shown that the GC/SIFT-MS combination allows for accurate trace gas quantification obviating the regular, time-consuming calibrations that are usually required for the more commonly used detectors of GC systems, and the positive identification of isomers in mixtures that is often challenging using SIFT-MS alone. Thus, the GC/SIFT-MS combination paves the way to more confident analyses of complex mixtures such as exhaled breath., (Copyright 2006 John Wiley & Sons, Ltd.)

In the title compound, C(16)H(18)N(6)O, an N-carbonylimidazole derivative of pyrazoline-1-carboximidamide, the pi-electron density of the N atom in the 1-position on the pyrazoline ring is delocalized through the amidine moiety and the adjacent carbonyl group. The imidazole ring, though coplanar with the rest of the molecule, is deconjugated. The pyrazoline ring adopts a flat-envelope conformation, having the substituted phenyl ring oriented perpendicular to the mean plane of the heterocycle. Both of the two potential hydrogen-bond donors are involved in intramolecular hydrogen-bonding interactions.

Reacting stoichiometric amounts of 1-(diphenylphosphino)ferrocenecarboxylic acid and [Ti(eta(5)-C(5)HMe(4))(2)(eta(2)-Me(3)SiC[triple-bond]CSiMe(3))] produced the title carboxylatotitanocene complex, [[mu-1kappa(2)O,O':2(eta(5))-C(5)H(4)CO(2)][2(eta(5))-C(5)H(4)P(C(6)H(5))(2)][1(eta(5))-C(5)H(CH(3))(4)](2)Fe(II)Ti(III)] or [FeTi(C(9)H(13))(2)(C(6)H(4)O(2))(C(17)H(14)P)]. The angle subtended by the Ti/O/O' plane, where O and O' are the donor atoms of the kappa(2)-carboxylate group, and the plane of the carboxyl-substituted ferrocene cyclopentadienyl is 24.93(6) degree.

The reduction of symmetric, fully-substituted titanocene dichlorides bearing two pendant omega-alkenyl groups, [TiCl2(eta5-C5Me4R)2], R = CH(Me)CH= CH2 (1a). (CH2)2CH=CH2 (1b) and (CH2)3CH=CH2 (1c), by magnesium in tetrahydrofuran affords bis(cyclopentadienyl)titanacyclopentanes [Ti(IV)[eta1:eta1: eta5:eta5-C5Me4CH(Me)CH(Ti)CH2CH(CH2(Ti))CH(Me)C5Me4]] (2a), [Ti(IV)[eta1:eta1:eta5: eta5-C5Me4(CH2)2CH(Ti)(CH2)2CH(Ti)(CH2)2C5Me4]] (2b) and [Ti(IV)[eta1:eta1:eta5:eta5-C5Me4(CH2)2CH(Ti)CH(Me)CH(Me)CH(Ti)(CH2)2C5Me4]](2c), respectively, as the products of oxidative coupling of the double bonds across a titanocene intermediate. For the case of complex 1c, a product of a double bond isomerisation is obtained owing to a preferred formation of five-membered titanacycles. The reaction of the titanacyclopentanes with PbCl2 recovers starting materials 1a from 2a and 1b from 2b, but complex 2c affords, under the same conditions, an isomer of 1c with a shifted carbon - carbon double bond, [TiCl[eta5-C5Me4(CH2CH2CH=CHMe)]2] (1c'). The titanacycles 2a-c can be opened by HCl to give ansa-titanocene dichlorides ansa-[[eta5:eta5-C5Me4CH(Me)CH2CH2CH(Me)CH(Me)C5Me4]TiCl2] (3a), ansa-[[eta5:eta5-C5Me4(CH2)8C5Me4]TiCl2] (3b), along with a minor product ansa-[[eta5:eta5-C5Me4CH2CH=CH(CH2)5C5Me4]TiCl2] (3b'), and ansa-[[eta5:eta5-CsMe4(CH2)3CH(Me)CH(Me)CH=CHCH2C5Me4]TiCl2] (3c), respectively, with the bridging aliphatic chain consisting of five (3a) and eight (3b, 3b' and 3c) carbon atoms. The course of the acidolysis changes with the nature of the pendant group; while the cyclopentadienyl ring-linking carbon chains in 3a and 3b are fully saturated, compounds 3c and 3b' contain one asymetrically placed carbon-carbon double bond, which evidently arises from the beta-hydrogen elimination that follows the HCl addition.

Aims: To investigate dose proportionality, dosing frequency, and ethnic aspects of the pharmacokinetics of bambuterol in asthmatic children, and to discuss the relationship with previous observations in adults., Methods: Forty-eight children in four different studies completed two double-blind bambuterol treatments each (daily doses of bambuterol hydrochloride): 12 preschool (5 mg x 2 vs 10 mg) and 12 school (10 mg vs 20 mg) Caucasians, 12 preschool (2.5 mg vs 5 mg), and 12 school (10 mg vs 20 mg) Orientals. Peak plasma concentrations and dosing interval area under curve (AUC) of bambuterol and the active metabolite terbutaline were assessed at steady state. Treatment differences were analysed statistically within each study. Differences between the studies and the relation to steady-state AUC in adults were described., Results: Dose proportionality was seen for terbutaline but not for bambuterol. Twice-daily dosing (2 x AUC(0,12 h)) could not be shown to differ from once-daily dosing (AUC(0,24 h)) in the preschool Caucasians. Mean AUC of terbutaline was 128 and 242 nmol l-1 h in the preschool Caucasians (5 mg/12 h; 10 mg/24 h), 213 and 406 nmol l-1 h in the Caucasian school children (10 mg; 20 mg), 87.4 and 202 nmol l-1 h in the Oriental preschool children (2.5 mg; 5 mg), and 356 and 640 nmol l-1 h in the Oriental school children (10 mg; 20 mg). Oriental school children had higher plasma concentrations of bambuterol and terbutaline than Caucasian school children. The strict ethnic implication of the difference could not be elucidated, because demographic data were not perfectly matched. Terbutaline AUC was only moderately increased in the Caucasian school children compared with Caucasian adults. The increase was more pronounced in Oriental children and in some preschool Caucasians. The highest concentration of terbutaline, 58 nmol l-1, was seen in an Oriental school child after a 20 mg dose., Conclusions: Caucasian school children can be given bambuterol hydrochloride very much as Caucasian adults, 10 or 20 mg once daily, but Oriental preschool and school children plus preschool Caucasians should be given lower doses.

A case of chronic recurrent multifocal osteomyelitis in a 14-year-old girl is presented. The disease had an initial aggressive osteolytic appearance involving both the maxilla and the mandible. Conservative treatment with minimal surgical intervention has been successful in this case during a 2-year follow-up period. The value of magnetic resonance imaging and bone scintigraphy in this case and the cause of chronic recurrent multifocal osteomyelitis is discussed.

Background: Pulmonary administration of beta 2-agonists by means of pressurized metered dose inhaler is widely used in the treatment of asthma. Young children have difficulties in using these inhalers unless a spacer device is used. To overcome this problem inspiratory flow driven dry powder inhalers have been developed., Objective: The aim of this study was to compare the efficacy and safety of the two powder inhalers Bricanyl Turbuhaler (terbutaline sulphate 0.5 mg t.i.d.) and Ventolin Rotahaler (salbutamol 0.4 mg t.i.d.) in 20 children 2 to 6 years old with mild to moderate asthma., Methods: The study had an open randomized crossover design with 1 week run-in without treatment and the two treatment periods of 2 weeks each. Efficacy was measured with peak expiratory flow determination, asthma symptom scores, and need for rescue medication. Adverse events were recorded., Results: Peak expiratory flow increased significantly (P < .001) after both treatments. There were no statistically significant differences in peak expiratory flow, asthma symptom scores, need for extra inhalations, or adverse events between the devices. Most children (parents) preferred the Turbuhaler., Conclusion: Both Bricanyl Turbuhaler and Ventolin Rotahaler seem to be effective and well tolerated in the treatment of asthma in preschool children. Of special interest is that even the youngest children in the study group were able to use these powder inhalers.