Noninvasive, direct visualization of macro-reentrant circuits by using magnetocardiograms: initiation and persistence of atrial flutter

AIMS

We analysed the cardiac magnetic fields on the body surface to visualize electrical currents noninvasively during reentrant arrhythmias.

METHODS AND RESULTS

Seven patients with counterclockwise atrial flutter (AFL) were studied during 17 episodes of AFL using 64-channel magnetocardiograms (MCGs) and electrophysiological study. Eight of the episodes were paroxysmal AFL, in which MCGs were recorded from the time of spontaneous onset to the time of termination. We constructed iso-magnetic field maps of the tangential components and produced MCG animations. With respect to AFL initiation, an atrial premature complex induced AFL. Prior to the initiation of AFL, atrial fibrillation (AF) transiently occurred. The cardiac magnetic fields revealed a single peak during sinus rhythm or with premature complexes but a disorganized pattern during AF. When AF transformed to AFL, the magnetic fields changed from a disorganized pattern to a single peak at first and then evolved to a circular pattern. During persistent AFL, the magnetic source moved in a counterclockwise circuit.

CONCLUSION

MCG animation can be used to visualize the sequence in which a premature complex transforms sinus rhythm to AFL via AF. Our findings indicate that MCGs can be used to identify noninvasively the mechanisms responsible for atrial tachyarrhythmias.

FAK overexpression is correlated with tumour invasiveness and lymph node metastasis in oesophageal squamous cell carcinoma

Focal adhesion kinase (p125(FAK); 'FAK') is a tyrosine kinase that is localised to cellular focal adhesions and is associated with a number of other proteins, such as integrin adhesion receptors. We performed an immunohistochemical analysis of FAK protein expression to determine the relationship between FAK overexpression and clinicopathological factors in oesophageal squamous cell carcinoma (ESCC). We examined tissue specimens that had been removed from 91 patients with thoracic oesophageal cancer who had undergone surgery between 1983 and 2001. Immunohistochemical staining was performed by the standard streptavidin-biotin method. Seven human ESCC cell lines-TE-1, TE-2, TE-8, TE-13, TE-15, TT, and TTn-and one immortalized human keratinocyte cell line-HaCaT-were used in Western blot analysis. Immunostaining of FAK was seen in the cytoplasm of cancer cells, particularly in cells located in the invasive fronts of cancer nests. FAK overexpression was detected in 54 of the 91 patients (59.3%). Significant correlations were observed between FAK overexpression and cell differentiation (P=0.0057), depth of tumour invasion (P=0.0023), presence of regional lymph node metastasis (P=0.0097), number of lymph node metastases (P=0.0026), and disease stage (P=0.012). The survival rates of patients with FAK-overexpressing cancer were significantly lower than those of patients without FAK-overexpression cancer (P=0.006). The 5-year survival rate of patients without FAK overexpression was 69%, whereas that of patients with FAK overexpression was 38%. On Western blot analysis, FAK was expressed at a high level in TE-1, TE-8, TE-15, and TT cells, at a moderate level in TE-2 and TTn cells, and at a low level in TE13 and HaCaT cells. FAK phosphorylation at tyrosine 397 was demonstrated in proportion to the intensity of FAK in all cell lines except TE15 and HaCaT. In conclusion, FAK overexpression of ESCC was related to cell differentiation, tumour invasiveness, and lymph node metastasis. Consequently, patients with ESCC who had FAK overexpression had a poor prognosis.

Microsatellite DNA polymorphism of human adrenomedullin gene in type 2 diabetic patients with renal failure

BACKGROUND

Adrenomedullin (AM) is a hypotensive peptide widely produced in the cardiovascular organs and tissues such as the heart, kidney, and the vascular cells. We have previously cloned and sequenced the genomic DNA encoding human AM gene, and determined that the gene is located in the short arm of chromosome 11. The 3'-end of the gene is flanked by the microsatellite marker of cytosine adenine (CA) repeats. In this study, we investigated the association between DNA variations in AM gene and the predisposition to develop nephropathy in type 2 diabetes mellitus.

METHODS

Genomic DNA was obtained from the peripheral leukocytes of 233 normal healthy subjects (NH), 139 type 2 diabetic patients on hemodialysis (DM-HD), 106 control patients with type 2 diabetes without nephropathy (DM-C) and 318 hemodialysis patients due to chronic glomerulonephritis (CGN-HD). The genomic DNA was subject to polymerase chain reaction (PCR) using a fluorescence-labeled primer, and the number of CA repeats were determined by polyacrylamide gel electrophoresis (PAGE).

RESULTS

In our Japanese subjects, there existed four types of alleles with different CA-repeat number; 11, 13, 14, and 19. The frequencies of these alleles were 11: 27.7%, 13: 32.8%, 14: 35.6%, and 19: 3.9% in NH. These allele frequencies were not significantly different in DM-C and CGN-HD. However, DM-HD showed significantly different distribution of allele frequency from other groups (chi 2 = 18.9, P = 0.026). Namely, the frequency of 19-repeat allele in DM-HD was higher (9.0%) than NH, DM-C, and CGN-HD (P = 0.005, 0.041, and 0.004, respectively).

CONCLUSION

The microsatellite DNA polymorphism of AM gene may be associated with the genetic predisposition to develop nephropathy in Japanese patients with type 2 diabetes mellitus.

A case of body stalk anomaly arising in the second baby of a triplet pregnancy after in-vitro fertilization and embryo transfer

We report a case of body stalk anomaly arising in the second baby of a triplet pregnancy after in-vitro fertilization and embryo transfer (IVF-ET). Body stalk anomaly or limb-body wall complex is a rare congenital anomaly with a series of similar clinical manifestations and poor prognosis. IVF-ET is an effective treatment for various types of infertility. We summarize and discuss herein the relation with the sequence of genesis for such malformations and multiple pregnancies after IVF-ET.

Variations of human adrenomedullin gene and its relation to cardiovascular diseases

The studies concerning the structure and variations of the human adrenomedullin (AM) gene are reviewed, and their relations to the gene function and genetic predisposition to cardiovascular diseases are discussed. The genomic human AM gene is composed of four exons, and the whole nucleotide sequence corresponding to mature AM resides in the fourth exon. In chromosomal sublocalization, the AM gene is located in the distal portion of the short arm of chromosome 11 (11p15.1-3). Analysis of the promoter region of the AM gene has revealed that two transcription factors, nuclear factor for interleukin-6 expression (NF-IL6) and activator protein 2 (AP-2), participate in the regulation of AM gene expression. It is surmised that NF-IL6 mediates inflammatory stimuli and AP-2 mediates signals of phospholipase C and protein kinase C activation. In addition to these factors, hypoxia induces AM gene expression via the hypoxia inducible factor-1 (HIF-1) binding site. The 3'-end of the AM gene is flanked by a microsatellite marker of cytosine adenine (CA) repeats. In Japanese, there are four types of alleles with different CA-repeat numbers: 11, 13, 14 and 19. It is suggested that existence of the 19-repeat allele is associated with genetic predispositions to develop essential hypertension and diabetic nephropathy.

Classifying cases of fetal Wolff-Parkinson-White syndrome by estimating the accessory pathway from fetal magnetocardiograms

The paper presents an evaluation of the possibility of using fetal magnetocardiogram (FMCG) signals to estimate and classify the accessory pathway in fetal Wolff-Parkinson-White (WPW) syndrome. The FMCG signals of two fetuses with WPW syndrome (type A) were detected using a 64-channel superconducting quantum-interference device system. An average across the cycles of these signals was taken to obtain clear WPW signals. To determine the direction and position of the accessory pathway in a fetal heart accurately, the accessory pathway and activated pathway at the peak of the QRS complex thus obtained were estimated for each fetus, using a single-dipole model. The phase angle (about 90 degrees) between the equivalent current dipoles (ECDs) was the same for both fetuses. This angle suggested that the accessory pathway is in the left side of the heart, i.e. that the pathway exists in the left ventricle, which indicates type A WPW syndrome. Identification of the position of the accessory pathway in a fetus with WPW syndrome from the angle between the ECD of the accessory pathway and the ECD of the peak in the QRS complex was thus demonstrated.

Positive association of CYP11B2 gene polymorphism with genetic predisposition to essential hypertension

Predispositions to essential hypertension and cardiovascular diseases are possibly associated with gene polymorphisms of the renin-angiotensin system. Gene polymorphisms of angiotensinogen and angiotensin-converting enzyme genes have been suggested to be risk factors for hypertension and myocardial infarction. Concerning the polymorphism of aldosterone synthase (CYP11B2) gene, earlier studies have shown inconsistent results in terms of its relation to hypertension. In the present case-control study, we investigated the association of -344T/C polymorphism in the promoter region of human CYP11B2 gene with genetic predisposition to hypertension. The genotype of -344T/C polymorphism was determined in essential hypertension subjects (n=250) and normotensive subjects (n=221). The distributions of three genotypes (TT, TC, and CC) were significantly different between the hypertensive and the normotensive groups (chi(2)=9.61, P=0.008). Namely, the frequency of C allele was higher in the hypertensive patients than in the normotensive subjects (34.2 vs 26.5%, P=0.010). Our data suggest that the -344C allele of CYP11B2 gene polymorphism is associated with the genetic predisposition to develop essential hypertension.

Seven-day triple therapy with omeprazole, amoxycillin and clarithromycin for Helicobacter pylori infection in haemodialysis patients

BACKGROUND

Triple therapy is accepted as the treatment of choice for Helicobacter pylori eradication, but there is no consensus on how long the therapy should be maintained in haemodialysis (HD(+)) patients. Our aims in this study were to evaluate the safety and efficacy of the 7-day triple therapy in HD(+) patients.

METHOD

Forty-seven HD(+) and 55 HD(-) patients with dyspepsia underwent endoscopy. The prevalence of H. pylori was detected by Giemsa stain, followed by the urea breath test (UBT). H. pylori(+) patients were scheduled to undergo 7-day triple therapy and the success of eradication was investigated by UBT.

RESULTS

Forty-five (44%) patients were positive for H. pylori. Forty of them underwent triple therapy and 39 (98%) patients completed the treatment. Eradication was successful in 32 (82%) and unsuccessful in 7 (18%) patients. There was no significant difference between these groups in age, gender, endoscopic findings or HD, and only previous treatment was significant for eradication failure by univariate and multivariate logistic regression analysis. Side effects were observed in 2 (15%) of 13 HD(+) and 3 (11%) of 27 HD(-) patients, and one HD(-) patient had to stop medication because of severe nausea and vomiting. The eradication rate was 93% (28/30) in patients without previous treatment. The triple therapy was unsuccessful in 7 patients, and 4 of them again underwent 7-day triple therapy, but all resulted in failure.

CONCLUSIONS

Seven-day triple therapy is safe and effective for primary treatment of H. pylori infection in both HD(+) and HD(-) patients, but a new treatment is necessary for patients with previous treatment.

Molecular genetic analysis of the Am phenotype of the ABO blood group system

BACKGROUND AND OBJECTIVES

Many sequences of variants in the ABO blood group system have been analysed, but genetic information is not available on the rare Am phenotype blood group. We isolated the Am phenotype in one family and performed molecular analysis on this allele.

MATERIALS AND METHODS

Exons 6 and 7 of the ABO gene were analysed using genomic DNAs from members of one family containing Am phenotype individuals via polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing.

RESULTS

In the Am allele, two single base substitutions were detected compared with the A101 allele. Both were C --> T mutations at nucleotide positions 467 and 761. PCR-RFLP using the AccI restriction enzyme was performed to detect the Am allele in 214 samples that had already been determined as type A or O by serological tests, but no sample was found to contain an Am allele.

CONCLUSIONS

In this study a new allele with a single-base substitution at nucleotide position 761 was identified in the Am phenotype. We designated this new allele as A112 (according to the guidelines for human gene nomenclature) and determined that PCR-RFLP analysis using the AccI restriction enzyme will be useful for detecting this allele.

Ileoileal intussusception and ileal stricture associated with necrotizing enterocolitis in a premature infant: report of a case

A 630-g male infant developed presumed necrotizing enterocolitis (NEC) after fungal enteritis that resulted in subsequent fungal septicemia associated with pneumoperitoneum on the 9th day of life. Urgent percutaneous Penrose drainage was required. During the operation on the 14th day, an ileoileal intussusception and an ileal stricture were found with perforations on each oral side of the lesions. The distinction between NEC and intussusception in premature infants when they coexist can be difficult, as these conditions share common symptoms. The relation between ischemic injury and dysmotility of the intestine is also discussed. The similarity of intrauterine fetal distress and NEC in premature infants, as seen in the present case of the intussusception associated with focal NEC, suggests that mesenteric and enteric vascular ischemia could be one trigger of intussusception in neonates.

Visualisation method of spatial interictal discharges in temporal epilepsy patients using magneto-encephalogram

The aim of the study was to develop a method for investigating how interictal epileptic discharges in temporal epilepsy patients are activated spatially. The activity was measured using magneto-encephalography (MEG). The MEG data were used to produce a current-arrow map that reflected the topographic distribution of the electrical current for each peak epileptic waveform. A large current distribution was obtained that appeared to be contained in the limbic structure, in each temporal lobe. The large current orientation indicated two opposite directions. Furthermore, the decrease in the maximum strength of the current-arrow, depending on the medication (e.g. the decrease from 11 to 6 pT m-1 in the left temporal lobe (contralateral stimuli)), suggested that the discharge distributions could be used to verify the efficacy of medication. Thus the topographical visualisation method could be a new strategy for diagnosis in temporal epilepsy patients.

Detection of atrial-flutter and atrial-fibrillation waveforms by fetal magnetocardiogram

Two cases of fetal tachycardia are reported: atrial flutter and fibrillation. The waveforms from each case were detected by fetal magnetocardiograms (FMCGs) using a 64-channel superconducting quantum interference device (SQUID) system. Because the magnitude of supraventricular arrhythmia signals is very weak, two subtraction methods were used to detect the fetal MCG waveforms: subtraction of the maternal MCG signal, and subtraction of the fetal ORS complex signal. It was found that atrial-flutter waveforms showed a cyclic pattern and that atrial-fibrillation waveforms showed f-waves with a random atrial rhythm. Fast Fourier transform analysis determined the main frequency of the atrial flutter to be about 7Hz, and the frequency distribution of atrial fibrillation consisted of small, broad peaks. To visualise the current pattern, current-arrow maps, which simplify the observation of pseudo-current patterns in fetal hearts, of the averaged atrial flutter and fibrillation waveforms were produced. The map of the atrial flutter had a circular pattern, indicating a re-entry circuit, and the map of the atrial fibrillation indicated one wavelet, which was produced by a micro-re-entry circuit. It is thus concluded that an FMCG can detect supraventricular arrhythmia, which can be characterised by re-entry circuits, in fetuses.

Non-Hodgkin's lymphoma of the ascending colon in a patient with becker muscular dystrophy: report of a case

We herein present the findings of a 10-year-old boy with non-Hodgkin's lymphoma of the ascending colon which caused intussusception and intestinal bleeding. He had a history of Becker muscular dystrophy. However, he had neither hypertrophic calves nor cardiomyopathy, and his serum creatine kinase (CK) level always exceeded 2000 IU/l. Preoperatively, a laboratory examination revealed high serum levels of CK (2038IU/l), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH), and the blood hemoglobin level was 7.0g/dl. A barium enema examination revealed an intussusception in his ascending colon, which was found to be a highly vascular tumor on Doppler ultrasound scans. A right hemicolectomy was performed. Macroscopically, the 5 x 6 x 8-cm solid tumor of the ascending colon resembled a submucosal tumor and had two ulcerous lesions at the tip. The tumor was histologically diagnosed to be a diffuse large B-cell lymphoma of the ascending colon. General examinations revealed no involvement of lymphoma postoperatively. At 13 months after surgery, the CK (37861U/l), AST (110lU/l), ALT (1381U/ l), and LDH (420lU/l) levels are still high, and the patient is doing well without any signs of recurrence.

Disseminated peritoneal adenomucinosis associated with a panperitonitis-like onset: report of a case

A 59-year-old man was admitted to our department due to a fever of unknown origin. Abdominal ultrasonography and computed tomography showed a large cystic mass in the lower abdomen and a massive amount of abdominal fluid. A laparotomy was performed under a diagnosis of panperitonitis. Diffuse pyogenic gelatinous ascites and a large cystic mass with a grayish wall, and a hard solid lesion in part were found. The microscopic findings of the hard solid lesion showed calcification, osteogenesis, and focal epithelial proliferation in a tiny area consisting of mucinous cells with no significant cytologic atypia. The remaining part of the cystic wall and small cystic lesions were hyalinized, fibrous, or necrotic tissue. Since a total resection of the masses was not possible, the patient received adjuvant chemotherapy with cisplatin followed by the administration of mitomycin C and 5-fluorouracil. An abdominal fistula with the excretion of pyogenic gelatinous fluid occurred, but the patient is still alive and doing well over 2 years postoperatively. The primary site of this tumor could unfortunately not be identified.