Cerebral infarction in acute promyelocytic leukemia at initial presentation

We report on a 3 year old girl with acute promyelocytic leukemia (APL) with cerebral infarction due to disseminated intravascular coagulation (DIC) at initial presentation. She was hospitalized because of unconsciousness and petechiae on the chest wall and extremities. Cerebral ischemia and infarction were found on computed tomography scan and magnetic resonance imaging. Peripheral bood content was hemoglobin 7.3 g/dL, white blood cells 1.0 × 10³cells/μL (31% blasts) and platelet count was 12 × 10³cells/μL. Fragmented erythrocytes were frequently observed on May-Giemsa stained blood smears. Bone marrow aspirates showed normal cellularity, with 60.4% blasts, containing faggot cells. The blasts were positive for peroxidase. Therapy was begun; however, the patient died 1 week after admission.     

Modulation of bullous pemphigoid antigen gene expression by γ-interferon in cultured keratinocytes

Bullous pemphigoid (BP) is characterized by the production of autoantibodies against BP antigens. gamma-interferon (gamma-IFN), a T-cell lymphokine, is known to enhance the expression of several cell-surface proteins. In this study, keratinocytes were cultured in the presence of gamma-IFN, the expression of BP antigen protein was examined by flow cytometry and BP antigen messenger RNA (mRNA) (encoding 230-kDa protein) was quantified by slot-blot hybridization. The results indicated that BP antigen gene expression by keratinocytes was upregulated by gamma-IFN. This enhancement of gene expression was detected at both the protein and mRNA level, suggesting pretranslational regulation. These results imply the involvement of not only humoral immunity but also cell-mediated immunity in the development of BP.     

Intravascular papillary endothelial hyperplasia

Intravascular papillary endothelial hyperplasia (IPEH) was first described by Masson.1 It is characterized by the development of endothelial-lined papillary projections in a vascular lumen. In Japan the disease was first reported by Tanimura et al.² in 1976, and since then over 30 cases have been described. In this reort we describe a case of IPEH together with the review of these Japanese cases.     

Bile acids influence hepatic chemiluminescence in normal and oxidative-stressed rats†

The aim of the present study was to clarify whether bile acids influence chemiluminescence (CL) in the liver in vivo. Hepatic CL was determined on the surface of the liver of anaesthetized rats by using a photon counter. In normal rats, hepatic CL was significantly decreased 30 min after enteral administration of chenodeoxycholic acid (CDCA) or deoxycholic acid (DCA), but returned to its initial level 3 h later, after part of the CDCA administered was metabolized. Ursodeoxycholic acid (UDCA) and cholic acid had no effect on CL. In contrast, hepatic CL was markedly increased 30 min after CDCA or DCA administration in rats given either buthionine sulphoximine (BSO), an inhibitor of γ-glutamylcysteine synthetase, or diethyldithiocarbamate (DDC), an inhibitor of both superoxide dismutase and glutathione peroxidase. Chenodeoxycholic acid further increased the CL of BSO- or DDC-treated rats during inhalation of oxygen via a tracheal cannula. Coadministration of UDCA eliminated the effects of CDCA on the hepatic CL of normal and BSO- or DDC-treated rats with or without oxygen inhalation. We conclude that cytotoxic bile acids, such as CDCA, increase CL in the antioxidants-depleted or oxidative-stressed liver in vivc, but that UDCA prevents CDCA from developing CL.     

STUDIES ON PEPTIDES

The tetradecapeptide amide corresponding to the entire amino acid sequence of a wasp venom (polistes mastoparan), isolated from Polistes jadwagae, was synthesized using the trifluoroacetic acid-thioanisole deprotecting procedure.     

Discrimination between His-bundle and the Right Bundle Branch during Electrophysiologic Studies

Background: The purpose of this study was to identify the His-bundle (HB) versus right bundle branch (RBB) during electrophysiologic studies, using the V3 phenomenon, and to compare the timing of HB versus RBB potentials of sinus cycles (His-ventricular [H-V] interval).
Methods: The study enrolled 16 patients without structural heart disease, who underwent electrophysiologic studies during which the H-V interval was within normal limits and the V3 phenomenon was induced during recordings of the HB and the RBB potentials by a multi-electrode catheter. The recording site of the earliest HB potential just before the V3 phenomenon was defined as the branching portion of His bundle (HBBP), the site immediately proximal to the HBBP as the HB, and the site immediately distal to the HBBP as the RBB.
Results: The HBBP was identified in all patients. In all cases but one patient, the H-V interval measured at the HB adjacent to the HBBP was ≥35 ms. However, in 12 patients, the H-V interval measured at the RBB adjacent to the HBBP was also ≥35 ms.
Conclusions: The electrophysiologic identification of HB versus RBB by simultaneous recordings of HB and RBB potentials during induction of the V3 phenomenon was feasible. When the discrimination between HB and RBB was based on the measurement of the H-V interval, the proximal portion of the RBB was frequently misidentified as the HB.     

Thoracoscopic Radiofrequency Ablation of the Myocardium

Radiofrequency (RF) catheter ablation has been used for the treatment of ventricular tachycardia (VT), however, in some patients VT might result from subepicardiai macroreentry that could be successfully terminated by epicardial approach. This study examined the feasibility of thoracoscopic RF ablation of myocardium from epicardium using a custom made electrode. In five mongrel dogs, the thoracoscope was introduced through the 7th intercostal space. A 500-kHz continuous wave RF energy was connected to a custom made multiple electrode probe. Under thoracoscopic guidance, the heart was exposed and the RF probe was introduced. RF ablation was performed on the nonvascular ventricular wall of the beating heart. The left ventricular free wall and right ventricular outflow tract were satisfactorily visualized and ablated. The total dose of RF energy ranged from 50 to 500 J. and the estimated volume of ablated lesions ranged from 41.0–799 mm³. There were significant correlations between the RF discharge output and the irradiated lesion volume (P < 0.01), and the depth of the lesions (P < 0.01). Grossly, after RF ablation the ventricular myocardium demonstrated a circular, well-demarcated area of thermal injury. Volume and depth of the lesion depended upon the total dose of delivered RF energy. Thoracoscopic RF ablation appears to be a minimally invasive and useful method for creating irradiated myocardial lesions from epicardial surface. This method could he technically feasible for the treatment of Vts for which endocardial RF ablation is ineffective.     

Repetitive Ventricular Responses Induced by Radiofrequency Ablation for Idiopathic Ventricular Tachycardia Originating from the Outflow Tract of the Right Ventricle

In 23 consecutive patients, radiofrequency (RF) ablation was used as treatment for idiopathic ventricular tachycardia (VT) originating from the outflow tract of the right ventricle. In this study, we focused on the repetitive ventricular response (> 5 consecutive QRS beats during RF application). The incidence and clinical implications of the repetitive ventricular response were examined through the results of endocardial mapping and RF ablation. VT origin was mapped as the earliest activation site during VT, and it was determined within 0.5 × 0.5 cm (narrow site) in 13 patients and wider than 0.5 × 0.5 cm (wide origin) in the other 10 patients. The repetitive ventricular response was induced during application of RF current in 14 of 23 patients (61%), and it was more frequently observed in VT from a wide origin (100%) than in the VT from a narrow site (31%). The QRS morphology of the repetitive ventricular response was identical to that of clinical VT. As RF application was continued and/or repeated, the RR interval of the repetitive ventricular response was gradually prolonged, the number of consecutive QRS complexes was decreased, and clinical VT was finally eliminated. The overall success rate of RF ablation was 96% (22/23 patients), and no complications were observed. In conclusion, a repetitive ventricular response was frequently observed in idiopathic right VT. The changing pattern of repetitive ventricular response, slowing, and/or disappearing was consistent with successful RF ablation.