Determination of the ratios of the aromatic amino acid residues by first- or second-derivative UV spectrometry for a simple characterization of peptides

A method for the simultaneous determination of the ratios of the three aromatic amino-acid residues in peptides was set up in acidic conditions. Binary and ternary mixtures of these amino acids were prepared, and first- and second-derivative spectra then calculated from their 0.1 nm resolution spectra between 240 and 320 nm. Certain spectral bands were chosen to differentiate tyrosine from tryptophan on the first-derivative spectra, and phenylalanine from tyrosine and tryptophan on the second-derivative spectra. Variation of the amplitude of the chosen bands was shown to be a linear function of the ratio of the aromatic amino acids in the mixture. This technique was validated with peptides whose sequence was known. The difference between theoretical and experimentally determined ratios was lower than 10%. Since the results are obtained as ratios, neither the concentration nor the nature of the peptide has to be known. The feasibility of application using a photodiode array detector with high resolution in reversed-phase high-performance liquid chromatography is discussed. © Munksgaard 1995.     

Daytime continuous polysomnography predicts MSLT results in hypersomnias of central origin

In the diagnostic work‐up of hypersomnias of central origin, the complaint of excessive daytime sleepiness should be objectively confirmed by MSLT findings. Indeed, the features and diagnostic utility of spontaneous daytime sleep at 24 h continuous polysomnography (PSG) have never been investigated. We compared daytime PSG features to MSLT data in 98 consecutive patients presenting with excessive daytime sleepiness and with a final diagnosis of narcolepsy with cataplexy/hypocretin deficiency (n = 39), narcolepsy without cataplexy (n = 7), idiopathic hypersomnia without long sleep time (n = 19), and ‘hypersomnia’ with normal sleep latency at MSLT (n = 33). Daytime sleep time was significantly higher in narcolepsy‐cataplexy but similar in the other groups. Receiver operating characteristics (ROC) curves showed that the number of naps during daytime PSG predicted a mean sleep latency ≤8 min at MSLT with an area under the curve of 0.67 ± 0.05 (P = 0.005). The number of daytime sleep‐onset REM periods (SOREMPs) in spontaneous naps strikingly predicted the scheduled occurrence of two or more SOREMPs at MSLT, with an area under the ROC curve of 0.93 ± 0.03 (P < 10^?12). One spontaneous SOREMP during daytime had a sensitivity of 96% with specificity of 74%, whereas two SOREMPs had a sensitivity of 75%, with a specificity of 95% for a pathological REM sleep propensity at MSLT. The features of spontaneous daytime sleep well correlated with MSLT findings. Notably, the occurrence of multiple spontaneous SOREMPs during daytime clearly identified patients with narcolepsy, as well as during the MSLT.     

Factors affecting dental fear in French children aged 5–12 years

International Journal of Paediatric Dentistry 2010; 20: 366–373 Background. While dental anxiety is often correlated with prior negative dental experience, prevention of dental anxiety should in theory include early exposure to the dental setting. Objective. We set out to evaluate factors affecting dental fear in French children. Methods. Dental fear was evaluated using a visual analogue scale (DF‐VAS) in a group of 1303 French children (681 boys and 622 girls) aged 5–11 years (mean: 8.12 years, SD: 1.42 years). Indicators of caries and oral hygiene were evaluated on dental examination. Indicators of well‐being related to oral health, dental experience, and oral health education were collected via a structured interview. Results. Dental fear was scored low in 75.7% (DF‐VAS 0–3), moderate in 16.7% (DF‐VAS 4–6), and high in 7.6% (DF‐VAS 7–10). DF‐VAS decreased statistically with experience of a prior dental visit. Children who had at least one decayed tooth presented a higher level of dental fear than those with no decay, while children with fillings were significantly less anxious than those without previous dental care. Conclusions. This study shows that for children aged 5–12 years, prior experience of the dental setting can act as a positive component of dental fear.     

The first report of a patient with interrupted inferior vena cava,multiple post-renal veins and azygos-hemiazygos continuation

The first case of a patient with interrupted inferior vena cava, four post-renal veins and an azygoshemiazygos continuation is presented. The complicated anomalies were omphalocele and atrial septal defect. Cine-magnetic resonance imaging and cardiac catheterization showed an anomalous retroaortic left innominate vein, azygos-hemiazygos continuation in the prerenal portion, arch formed renal vein in the renal portion and four embryonic vessels in the post-renal portion. Combination of these anomalies in the major venous system suggested that the inferior vena cava had failed to form and that the bilateral embryonic venous system, postcardinal and supracardinal veins persisted to be the systemic venous channels.     

Galanin-like immunoreactive endocrine cells in bovine pancreas

Pancreata of fetal, neonatal and adult cattle were studied immunohistochemically for galanin. The results revealed galanin-like immunoreactivity both in the endocrine cells and in the neural elements. The galanin-like immunoreactive endocrine cells (Gal-LIEC) were confined to the large islets, and were not observed in the islets of Langerhans and exocrine pancreas. They were first detected at the third prenatal month. Their developmental profile showed an increase from fetal to early neonatal stage with a subsequent decrease towards adulthood. The considerable number of Gal-LIEC from late prepartum to early postpartum stage may imply functional significance of galanin during the perinatal development of cattle. Coexistence of galanin and insulin was also observed which may suggest autocrine interaction between the 2 hormones.     

Insertable Loop Recorder in Unmasking the Cause of Syncope

SIMANTIRAKIS, E.N., et al. : Insertable Loop Recorder in Unmasking the Cause of Syncope. During the last few years closed loop recorders are being used increasingly in the investigation of unexplained syncope. Our patient had a 5-year history of pre- and syncopal episodes in which the usual invasive and noninvasive tests were nondiagnostic. Finally, a loop recorder was implanted that revealed the cause of the syncope a few days after implantation: a fast, sustained, ventricular tachycardia originating from the right ventricular outflow tract. Loop recorders will undoubtedly contribute toward the decrease in the percentage of undiagnosed syncope cases and possibly to the reduction of the investigation cost.     

Signal-Aver aged Intracardiac Electrograms:

Signal Averaged Intracardiac Electrograms. Introduction : In patients with manifest accessory pathways, Kent potentials are often difficult to identify even at sites of successful catheter ablation, due largely to signal noise and catheter instability. We hypothesized that signal averaging the intracardiac electrogram recorded from the ablation catheter over a number of beats would improve the signal-to-noise ratio of the electrogram and aid in the detection of Kent potentials at accessory pathway locations.
Methods and Results : We retrospectively analyzed distal-pair electrograms recorded from 9 successful, 6 transiently successful, and 10 failed ablation sites in 10 patients with manifest accessory pathways who underwent catheter ablation. We developed custom software to finely align 20 to 30 consecutive sinus beats and compute the signal average of the electrogram (SAE) for each site. Kent potentials were classified as probable, possible, or absent in the raw ablation site electrogram and the SAE base on morphologic criteria. A measure of beat-to-beat signal instability, the variability quotient (VQ), was also computed for each site. Probable Kent potentials were found in the raw ablation site electrogram at only 2 of the 15 successful and transiently successful sites, but were found in the SAE at 10 of these sites (P = 0.008). Eight of the 9 successful sites had VQ < 0.2, suggesting stable catheter-tissue contact, while 3 of the 6 transiently successful sites had VQ > 0.2, indicating unstable contact.
Conclusions : Signal averaging the intracardiac ablation site electrogram enhances detection of Kent potentials at accessory pathway locations. Catheter instability can be quantified by signal variability analysis and, when high, may predict lack of successful ablation even at sites where Kent potentials are present.     

The Effect of DDD Pacing on Ergospirometric Parameters and Neurohormonal Activity in Patients with Hypertrophic Obstructive Cardiomyopathy

This study examined the acute and long-term effects of DDD pacing on ergospirometric parameters and neurohormonal activity in patients with hypertrophic obstructive Cardiomyopathy (HOCM). We studied eight patients (five males), aged 56 ± 7 years, with HOCM refractory to drugs. In all patients a DDD pacemaker was implanted and programmed with an atrioventricular (AV) delay that insured full ventricular activation. The patients underwent echocardiographic examination and exercise stress testing before and 3 days, 3 months, and 12 months after pacemaker implantation. Oxygen consumption was measured at the anaerobic threshold (VO_2AT) and peak exercise (pVO₂). Atrial natriuretic peptide (ANP) and cyclic adenosine monophosphate (c-AMP) levels were measured concomitantly. Left ventricular outflow tract (LVOT) pressure gradient decreased significantly from 70 ± 18 to 25 ± 12 mmHg (P < 0.05) 3 days after pacing and remained unchanged at 3 and 12 months. pVO₂ and VO_2AT increased significantly, from 20.1 ± 3 to 23.4 ± 3 mL/kg/min and from 16 ± 3 to 17.8 ± 2 mL/kg/min, respectively (P < 0.05). This improvement continued up to 3 months, and then remained stable until the end of the 12-month follow-up period. ANP levels decreased at 3 days from 85.4 ± 5.7 to 75.4 ± 7.3 fmol/mL (P < 0.05), and remained unchanged over the 12 months. c-AMP levels did not change significantly after the onset of pacing. DDD pacing in patients with HOCM not only reduces the LVOT pressure gradient but also causes a significant early and long-term improvement in exercise capacity and neurohormonal profile.     

Unrelated donor bone marrow transplantation for children and adolescents with aplastic anaemia or myelodysplasia

Allogeneic transplantation from an HLA-matched family member has been shown to be effective in reconstituting normal haemopoiesis in young people with severe cytopenias, classified as myelodysplastic syndrome (MDS) or severe aplastic anaemia (SAA). Unrelated donor transplant is a therapeutic choice for patients without a suitable family member donor. We report the outcome of seven patients < 20 years old with SAA and 10 with MDS treated with BMT from an HLA A,B DRB1 matched ( n  =8) or A or B locus mismatched ( n  =9) unrelated donor at the University of Minnesota between March 1988 and August 1995. Primary graft failure occurred in two patients and secondary graft failure in one, who was subsequently successfully engrafted with a second donor marrow infusion. Grades II–IV GVHD occurred in 10/16 (63%), and grades III–IV in 6/16 (37%) evaluable patients. Nine of the 17 patients (six with MDS and three with SAA) survive with full donor chimaerism, a median of 1.2 years post-BMT (range 3 months to 7 years). We recommend early referral for consideration of unrelated donor BMT for young patients with MDS, and patients with SAA without response to immunosuppression.