Electrophysiological Characteristics of Localized Reentrant Atrial Tachycardia Occurring After Catheter Ablation of Long-Lasting Persistent Atrial Fibrillation

Background: Mapping of recurrent atrial tachycardia (AT) after extensive ablation for long-lasting persistent atrial fibrillation (AF) is complex. We sought to describe the electrophysiological characteristics of localized reentry occurring after ablation of long-lasting persistent AF.
Methods: Out of 70 patients undergoing catheter ablation of long-lasting persistent AF, 9 patients (13%, 55 ± 8 years, 8 males) in whom localized reentry was demonstrated in a repeat ablation were studied. Localized reentry was defined as reentry in which the circuit was localized to a small area and did not have a central obstacle. The mechanism of AT was determined by electroanatomical and entrainment mapping.
Results: Nine localized reentries with cycle length of 243 ± 41 ms were mapped in 9 patients. The location of AT was the left atrial appendage in 4 patients, anterior left atrium in 2, left septum in 2, and mitral isthmus in 1. In all ATs, a critical isthmus of <10 mm in width was identified in the vicinity of the prior linear lesions or ostia of isolated pulmonary veins. Ablation of the critical isthmus, which was characterized by continuous low-voltage activity (median voltage: 0.15 mV, mean duration: 117 ± 31 ms), terminated AT and rendered it noninducible. Additionally, ablation was performed for all of inducible ATs. At 11 ± 7 months after the procedure, 8 of 9 patients (89%) were free from any arrhythmias.
Conclusions: After ablation of long-lasting persistent AF, localized reentry may arise from a site in the vicinity of the prior ablation lesions. Ablation of the critical isthmus eliminates the arrhythmia.     

CMV viraemia demonstrated in the serum of a patient with cytomegalovirus pneumonia

Summary. We attempted to demonstrate the expression of cytomegalovirus (CMV) particles in the serum of an acute lymphocytic leukaemia patient with CMV pneumonia. The serum sample was applied to an affinity column coupled with human monoclonal antibody C2 3 which recognizes the envelope glycoproteins of CMV virus and neutralizes the viral activity. The DNA obtained from each fraction was amplified by double polymerase chain reaction (PCR) and analysed by gel electrophoresis. Bands were clearly observed in the eluted fraction. These results strongly suggest that CMV particles exist in the sera of patients with CMV pneumonia.     

Neurovascular Bundle Decompression without Excessive Dissection for Tarsal Tunnel Syndrome

Tarsal tunnel syndrome (TTS) is an entrapment neuropathy of the posterior tibial nerve and its branches in the tarsal tunnel. We present our less invasive surgical treatment of TTS in 69 patients (116 feet) and their clinical outcomes. The mean follow-up period was 64.6 months. With the patient under local anesthesia we use a microscope to perform sharp dissection of the flexor retinaculum and remove the connective tissues surrounding the posterior tibial nerve and vessels. To prevent postoperative adhesion and delayed neuropathy, decompression is performed to achieve symptom improvement without excessive dissection. Decompression is considered complete when the patient reports intraoperative symptom abatement and arterial pulsation is sufficient. The sensation of numbness and/or pain and of foreign substance adhesion was reduced in 92% and 95% of our patients, respectively. In self-assessments, 47 patients (68%) reported the treatment outcome as satisfactory, 15 (22%) as acceptable, and 7 (10%) were dissatisfied. Of 116 feet, 4 (3%) required re-operation, initial decompression was insufficient in 2 feet and further decompression was performed; in the other 2 feet improvement was achieved by decompression of the distal tarsal tunnel. Our surgical method involves neurovascular bundle decompression to obtain sufficient arterial pulsation. As we use local anesthesia, we can confirm symptom improvement intraoperatively, thereby avoiding unnecessary excessive dissection. Our method is simple, safe, and without detailed nerve dissection and it prevents postoperative adhesion.     

Decreased variation of electrocardiographic R–R interval in patients with liver cirrhosis

Electrocardiographic R–R interval variations were assessed to determine the functional integrity of the cardiac vagal nervous system in 20 normal controls and 71 cirrhotic patients. The ratio of the coefficient of variation to standard prediction value was used as an index. The cirrhotic patients showed significant reductions in the ratio of the coefficient compared with controls (0.71 ± 0.27 vs 0.91 ± 0.14; P < 0.01). There was a significant relationship between decreased R–R interval variation and the liver function tests. The ratio of the coefficient increased with improvement in encephalopathy, and decreased with the development of encephalopathy. These results show that there is dysfunction of the cardiac vagal nervous system in patients with liver cirrhosis, and that this abnormality is partially reversible and might be related to liver dysfunction.     

Synthesis and solubility properties of peptide fragments of human hemoglobin α-chain (123-136)

The solubility prediction method for protected peptides was successfully applied to relatively small peptide fragments of human hemoglobin α-chain (123-136) which contained various polar amino acid residues such as Asp(OBzl), Glu(OBzl), Lys(Z), Ser(Bzl), and Thr(Bzl). As reported previously for hydrophobic peptides and human proinsulin C-peptide fragments, solubility data indicated that the insolubility of protected peptides having a <P_C > value below 0.90 appeared to begin at the octa- or nonapeptide sequence level and that β-sheet structure played an important role in the insolubility of peptides. When a peptide has a β-sheet structure in the solid state, we can clearly determine the critical chain length for peptide insolubility, the solubility dependence on solvent properties, and the solubility independence of amino acid compositions of peptides.     

Tertiary peptide bond containing-oligo(Leu)s

In order to elucidate the role of tertiary peptide bonds in the conformational development and solubility improvement of peptides, the conformational properties of oligo(Leu)s with the Pro residue and the Gly-(Dmob)Leu sequence were investigated in solution using i.r. absorption, CD, and molar rotation measurements. The i.r. absorption spectroscopy indicated that the peptides soluble in inert solvents such as CCl₄ and toluene had a predominantly β-sheet structure in these solvents. The conformations of the peptides in CCl₄ and toluene were essentially the same as those in a solid state, whereas in THF and in MeOH, the peptides examined were efficiently subjected to solvation, and a randomly coiled structure was predominant. In order to confirm the randomly coiled structure, measurements have been made of the molar rotations of the peptides in a variety of strong proton acceptor and donor solvents. CD measurements are also carried out in MeOH. Through the investigations, it was shown that the protection of peptide bonds and the insertion of the Pro residue had the same effect on conformational and solubilizing behaviors and induced onset of an unordered structure and easy solvation of the peptides in medium and high polarity-solvents.     

Phase I and Preliminary Phase II Studies on Aclacinomycin A in Patients with Acute Leukemia

Eight patients with acute nonlymphocytic leukemia (ANLL) andfive patients with acute lymphocytic leukemia were treated withaclacinomycin A. It was given daily by one-hour infusion indoses ranging from 0.33 to 0.70 mg/kg for seven to 20 days withoutother antileukemic agents. Two patients with ANLL achieved completeremission and one with ANLL achieved partial remission. Itsmajor toxic effects were myelosuppression and gastrointestinalsymptoms.