Detection of the mutation in facioscapulohumeral muscular dystrophy patients

The gene responsible for facioscapulohumeral muscular dystrophy (FSHD) was mapped to chromosome 4q35 by linkage analyses. Recently, the probe p13E-11 derived from the cosmid clone 13E, which has been mapped to 4qter, detected a polymorphic EcoRI fragment, usually greater than 28 kb in normal individuals. In sporadic and familial FSHD patients, a specific shorter fragment, usually smaller than 28 kb, was found to cosegregate with FSHD. Two FSHD patients are presented here. Patient 1 is a sporadic case of FSHD with healthy parents. He had a de novo mutation identified by Southern blot analysis using the above-mentioned probe. Patient 2 is a typical familial FSHD patient clinically and histologically. A rearranged and shortened EcoRI fragment was identified by molecular analysis. Southern blot analysis using the probe p13E-11 also indicated a rearranged EcoRI fragment in both patients.     

Origin of slow conformer conversion of triostin A and interaction ability with nucleic acid bases

The n.m.r. pattern of triostin A in weakly polar solvents was expalined by the presence of two symmetrical conformers. Its S-benzyl derivative still shows the n.m.r. pattern of two conformers, while des-N-tetramethyltriostin A, which lacks the N-methyl groups, gives one conformer. Therefore the slow interconversion of two conformers arises from the cis-trans isomerization of the N-methyl peptide bonds, but not from the reversal of the chirality around the S-S bond. Only one of the two conformers of triostin A interacts with adenosine and guanosine derivatives. Des-N-tetramethyltriostin A can also interact with the purine nucleosides, but more preferentially with the adenosine derivative.     

Gastrointestinal perforation in very low-birthweight infants

BACKGROUND: Spontaneous isolated gastrointestinal perforation (SIP) in very low-birthweight infants has been reported as a different disease entity from necrotizing enterocolitis (NEC). The objective of this study was to investigate the incidence and risk factors of NEC and SIP. METHODS: The authors reviewed the medical records of very low-birthweight infants who were admitted to Toho University Perinatal Center, Tokyo, Japan, between 1 January 1991 and 31 December 2002. The diagnosis of NEC was made with the finding of bloody gastric fluid or stool, abdominal distention, and abnormal abdominal X-ray findings such as pneumatosis intestinalis or fixed dilated intestinal loops. SIP was defined at laparotomy as the presence of an isolated gastrointestinal perforation surrounded by normal appearing bowel. RESULTS: A total of 556 very low-birthweight infants were included in this study. Of those, 15 infants were excluded because of major anomalies. Out of 541 infants, 14 were diagnosed to have NEC or gastrointestinal perforation. In total, 13 infants had gastrointestinal perforation and 10 were confirmed as SIP. Two SIP suggestive cases were included in SIP cases. There was only one case of NEC (0.2%) during 12 years in the authors' institute. Eight SIP cases had antenatal nonsteroidal anti-inflammatory drugs (NSAID). The treatment with antenatal NSAID was significantly associated with the incidence of SIP (p<0.001). CONCLUSION: The authors experienced only one proven case of NEC (0.2%), 12 cases of SIP (2.2%) among 556 very low-birthweight infants admitted during 12 years. Antenatal NSAID were strongly associated with SIP.     

Influence of Mobile Magnetic Resonance Imaging on Implanted Pacemakers

KISHI, R., et al.: Influence of Mobile Magnetic Resonance Imaging on Implanted Pacemakers. Purpose: Mobile magnetic resonance imaging (MRI) systems will be widely used in Japan. When traveling, mobile MRI generate alternating electromagnetic waves which may cause electromagnetic interference (EMI). This study was designed to determine whether this may influence the function of implanted pacemakers (PM). Methods and Results: The influence of the static magnetic fields was tested in the first method using a PM-human model (Phantom). Magnetic force was simultaneously measured. The PM was switched to the magnet mode within 90 cm from the vehicle, where the magnetic force was = 2 mT. In the second method, six phantoms were placed on the side of the road, facing in three different directions in X-Y-Z axis orientations, at 1.3 m and 2.0 m above the ground. The mobile MRI passed by at a distance of 1 m from the phantoms at the speed of 20 or 40 km/h. In these experiments, magnet mode switch of the PM was observed for 2 seconds when the vehicle passed close to the phantoms, though no electrical noise was recorded. Conclusion: Mobile MRI vehicles can switch a PM to magnet mode when the distance between patient and vehicle is <90 cm, regardless of whether the vehicle is moving or at a stop. Patients with implanted PM should not approach within <1 m of a mobile MRI. No other EMI-induced PM dysfunction was detected. (PACE 2003; 26[Pt. II]:527–529)     

Changes in Autonomic Nervous Activity after Catheter Ablation of Atrial Tachycardia Arising from the Atrioventricular Annulus

Radiofrequency (RF) catheter ablation of supraventricular tachycardias causes local parasympathetic denervation. This study used heart rate variability (HRV) to evaluate the effects of ablation of atrial tachycardia (AT) arising from the atrioventricular annulus (AVAT) on autonomic function. Ten patients with AVAT were referred for ablation (group AT) and compared with 8 patients with paroxysmal atrial fibrillation who underwent PV isolation (group Paf), and 13 patients with idiopathic ventricular tachycardia successfully treated by ablation (group VT). Time and frequency domain analysis of HRV on 24-hour ambulatory ECG recordings was performed before and after ablation. Root mean square of differences of consecutive N-N intervals (rMSSD), percentage of difference between consecutive N-N intervals >50 ms (pNN50), and high frequency (HF) component were measured to examine the effects on parasympathetic nerve activity. In group AT, rMSSD, pNN50, and HF decreased significantly after ablation, while they remained unchanged in group Paf and group VT. These observations suggest that parasympathetic denervation after ablation was limited to group AT, and depended on the site of energy delivery along the tricuspid or mitral valve as opposed to atrial or ventricular muscle.     

Analysis of the 13C-urea breath test for detection of Helicobacter pylori infection based on the kinetics of Δ-13CO2 using laser spectroscopy

We have previously reported on laser spectroscopy as a simple alternative to mass spectrometry. To validate a simplified ¹³C-urea breath test (UBT) with laser spectroscopy for the detection of Helicobacter pylori in clinical use, we evaluated the optimal time of breath sample collection. The ¹³C-UBT was carried out on each of 102 infected and 70 non-infected subjects (32 without eradication and 38 after eradication therapy). Breath samples were taken at five time points within 60 min followed by 100 mg of ¹³C-urea administration. The ratio of ¹³CO₂ to ¹²CO₂ was measured using laser spectroscopy and the recovery of tracer in the exhaled breath was calculated. Results were compared with histological and culture examinations of gastric biopsies to establish the infection status. For statistical evaluation of ¹³C-UBT, the optimal timing of breath sample collection was examined on the basis of the kinetics of Δ-¹³CO₂. In 32 H. pylori-negative patients (without therapy), the mean ± 2SD of Δ-¹³CO₂ was at its minimum 20 min after urea ingestion whereas in H. pylori-positive patients, the mean ± SD Δ-¹³CO₂ was maximum at 20 min. In addition, receiver operating characteristic (ROC) curve analysis showed that the cut-off value was estimated between 2.5–3.0 per mil (‰) at 20 min before therapy. Based on the histology and culture results, the sensitivity, specificity and positive and negative predictive values were 98.0%, 100%, 100% and 94.1%, respectively. In conclusion, ¹³C-UBT with laser spectroscopy is a non-invasive, simple, sensitive and specific test to determine H. pylori status. Our findings suggest that in clinical use, measurements made at 20 min after substrate administration could be recommended for most sensitive and specific ¹³C-UBT results.     

Traumatic bladder rupture managed successfully by laparoscopic surgery

A 61-year-old man presented to our emergency department with acute abdomen. The patient had extraperitoneal and intraperitoneal traumatic bladder injury, which was successfully managed with combined endoscopic and laparoscopic procedures.