The Cardiff paediatric laryngoscope blade: a comparison with the Miller size 1 and Macintosh size 2 laryngoscope blades.

The Cardiff paediatric laryngoscope blade is a single blade that has been designed for use in children from birth to adolescence. This open, randomised, crossover study compared the Cardiff blade with the straight, size 1, Miller laryngoscope blade in 39 infants under 1 years of age and the curved, size 2, Macintosh blade in 39 children aged 1-16 years. The same laryngoscopic view was obtained with the Cardiff and Miller blades in 26 patients; the view was better with the Cardiff blade in seven patients and better with the Miller blade in six (median (IQR [range]) grade of laryngoscopy 1 (1-2 [1-3]) vs. 1 (1-2 [1-3]), respectively; p = 0.405). The Cardiff blade was faster at gaining a view than the Miller blade (mean (SD) time 8.5 (2.9) s vs. 10.2 (3.5) s, respectively; 95% CI for difference -2.8 to -0.4; p = 0.009). The Cardiff and Macintosh blades produced the same view in 32 patients; the view was better with the Cardiff blade in seven patients (median (IQR [range]) grade of laryngoscopy 1 (1-1 [1-3]) vs. 1 (1-2 [1-3]), respectively; p = 0.008). There was no difference in time to gain these views: mean (SD) 8.7 (3.0) s vs. 9.3 (2.7) s, respectively (95% CI for difference -1.58 to 0.40; p = 0.237). The Cardiff paediatric laryngoscope blade compares favourably with these two established laryngoscope blades in children.

Antenatal minimal hydronephrosis: is its follow-up an unnecessary cause of concern?

The aim of this study was to determine if follow-up of antenatally diagnosed minimal hydronephrosis (anteroposterior renal pelvis diameter <10 mm) is justified or if it is an unnecessary cause of concern for the parents involved. A case-control study, with subjects and controls selected from the Wessex Antenatally Detected Anomalies Register was performed. Information regarding antenatal and postnatal follow-up, renal tract morbidity and degree of concern was obtained from a parental questionnaire. 70 of the 115 subjects contacted (60.9 per cent) and 52 of the 81 controls (64.2 per cent) returned the questionnaire. 65 of the 70 subjects (92.9 per cent) were rescanned postnatally when 28 cases (43.1 per cent) had resolved. Coexisting ureteric and/or calyceal dilatation was evident postnatally in 12 cases and this group was significantly more likely to have underlying pathology than the group with isolated renal pelvis dilatation. Subjects were significantly more likely than controls to have a UTI. The degree of concern was significantly greater in the subject group and subject parents thought about the result significantly more often than controls. From our results we concluded that the follow-up of minimal hydronephrosis can be modified. There is no need for repeated antenatal scanning, a change that could reduce the level of parental anxiety. Postnatal follow-up is required in all patients to exclude an underlying uropathy but again this can be modified, with the majority of patients requiring only an ultrasound scan. This reduced intensity of investigation accompanied with careful explanation to the parents should help to minimize their concerns.

Mössbauer spectroscopy of metalloproteins and the use of Fourier transforms.

A method for obtaining accurate, quantitative 57Fe Mössbauer spectra from biological samples is illustrated stepwise in a data reduction procedure. Exact criteria are presented for deciding when it is necessary to account for the effects of the Beer-Lambert law in the Mössbauer spectra from biological samples. This procedure makes extensive use of the fast Fourier transform and other computer techniques in its data reduction and its curve-fitting stages. A method for optimizing sample thickness is presented. The choice of truncation in Fourier space as a means to numerically stabilize the deconvolution procedure is defended. Several advantages for curve fitting in Fourier space are shown. Maximization of information content is discussed for Mossbauer spectral simulation techniques.

On the molecular and submolecular structure of the semiquinone cations of alloxazines and isoalloxazines as revealed by electron-paramagnetic-resonance spectroscopy.

The thermodynamically stable and, therefore, analytically most important alloxazine and isoalloxazine radical cations have been studied in detail by electron paramagnetic resonance (EPR) spectroscopy. Isotopic and chemical substitutions have been made as in earlier studies with the less stable neutral and anionic species. The experimental spectra have been calculated with the aid of a more sophisticated computer-simulation program than previously used. Excellent fits were obtained only when all of the following atoms were taken into account in the hyperfine coupling scheme: N-5 H, N-10 H or CH3, C-6 H, C-7 H, C-8 H or CH3 and C-9 H. An additional but small coupling constant was required for the fit. This latter coupling constant is assigned to the nitrogen atom(s) of the pyrimidine subnucleus of (iso)alloxazine radical cations. The EPR-active proton is attached to N-5 as we also found for the neutral flavosemiquinone. The alloxazine and isoalloxazine radical cations exhibit an identical hyperfine coupling scheme but differ especially in the pyrazine nucleus with respect to the spin density distribution. This suggests that the geometrical structure of the two kinds of radicals is somewhat different. The highest spin density is, however, located at N-5 of (iso)alloxazine as has been found for the other flavosemiquinone species. The hyperfine coupling constants are interpreted in terms of spin densities and comparison is made with the most recently available quantum chemical calculations. All monomeric flavosemiquinone species are compared with each other and their differences in the submolecular structure are discussed briefly.