[Subendocardial resection in the surgical treatment of ventricular arrhythmia in patients with ischemic heart disease]. / Subéndokardial'naia rezektsiia v khirurgicheskom lechenii zheludochkovykh aritmii u bol'nykh ishemicheskoi bolezn'iu serdtsa.

The authors have much experience in diagnosing and managing ventricular arrhythmias in patients with coronary heart disease. In most cases, the arrhythmogenic areas are present in the subendocardium and surgeries aimed at improving myocardial revascularization prove to be frequently ineffective in managing arrhythmias. Subendocardial resection proposed by the authors was used in 284 patients. Mortality rates were in 15%, the deaths were mainly due to phenomena of heart failure. Positive results were achieved in 160 (67%) patients. To evaluate the efficacy of the surgical management, the authors consider it advisable to apply programmed endocardial stimulation. The value of pre- and intraoperative mapping is the most important factor that determines the outcome of the surgical management. Subendocardial resection should be regarded as the method of choice just at early stages of the disease in patients with recurrent ventricular tachycardias occurring after acute myocardial infarction.

The identification of epitopic sites in human alpha 1-proteinase inhibitor.

Human alpha 1-proteinase inhibitor (alpha 1-PI) yielded nine fragments on cleavage with CNBr. The amino acid sequences of these fragments were determined. Three of these CNBr-cleavage fragments, namely fragment I (residues 64-220), fragment II (residues 243-351) and fragment III (residues 1-63), were found to bind rabbit polyclonal antibodies against chemically oxidized alpha 1-PI and mouse polyclonal antibodies against native alpha 1-PI by the Bio-Dot method (enzyme-linked immunosorbent assay on nitrocellulose). These fragments, I, II and III, inhibited by 60%, 25% and 5% respectively the binding between alpha 1-PI and the rabbit antibodies. Fragments I, II and III were subjected to proteolytic digestion, and 15, ten and five peptides were obtained from these fragments respectively. Only four of these peptides showed binding to the mouse antibodies against native alpha 1-PI. These were residues 40-63, 79-86, 176-206 and 299-323. A panel of monoclonal antibodies was prepared by conventional hybridoma technology, with chemically oxidized alpha 1-PI as the antigen. The ability of the monoclonal antibodies to bind native alpha 1-PI and CNBr-cleavage fragments I-III was determined. The monoclonal antibodies fell into three categories. Most (over 90%) belonged to group I, which was capable of binding alpha 1-PI and only fragment I. Antibodies in groups II and III bound alpha 1-PI and either fragment II or fragment III respectively. The ability of the peptides derived from proteolytic digestion of fragments I, II and III to bind three monoclonal antibodies representing each of the three groups was determined. Among all the peptides tested, only one (residues 176-206) derived from fragment I showed binding to the antibodies from group I, one (residues 299-323) derived from fragment II showed binding to the antibodies from group II, and one (residues 40-63) from fragment III showed binding to the antibodies from group III. Each of these three peptides also inhibited the binding between alpha 1-PI and the corresponding monoclonal antibodies. From these data we concluded that at least four epitopic regions (residues 40-63, 79-86, 176-206 and 299-323) were present in alpha 1-PI. Specific monoclonal antibodies to three of these sites were obtained.

Primary structure of human alpha1-protease inhibitor. The complete amino acid sequence of cyanogen bromide fragment II.

The complete amino acid sequence of a CNBr-fragment from human alpha1-protease inhibitor has been determined and is shown below. The peptide consists of 109 amino acid residues with 1 oligosaccharide unit. The 2 glutamic acid residues which have previously been shown to be substituted by lysine in the Z and by valine in the S mutant proteins are both located in this CNBr fragment. (formula: see text).

Intramembranous particles in erythrocyte, reticulocyte and erythroblastic leukemic cells of the rat: a model system for erythrocyte maturation.

The density and size distribution of intramembranous particles (IMP) were determined for cells of the erythroid series. The number and size of IMP were measured on both fracture faces of erythroblastic leukemia cells, phenylhydrazine-induced reticulocytes and mature erythrocytes. We found that the number of IMP adhering to the protoplasmic fracture face of the plasma membrane increased with increasing maturation, while the number of particles adhering to the external fracture face did not correlate with maturational stage. In general, the mean size of particles adhering to both fracture faces decreased with increasing maturation after the erythroblastic stage. We interpret these results to mean that the IMP seen are derived from more than one macromolecular species and that they are distributed asymmetrically in the plasma membrane.