A case with fistulas from both coronary arteries and the left bronchial artery to the pulmonary artery

A case with fistulas from both coronary arteries and the bronchial artery to the pulmonary artery is reported. We believe this is the first case report of an uncommon form of complex arteriovenous fistula diagnosed by selective angiography.     

Shortening of conduction time over arborized atrioventricular accessory pathway with Mahaim fibers physiology just before interruption during radiofrequency ablation

A 21-year-old woman had paroxysmal wide QRS tachycardia with a left bundle branch block configuration and a retrograde conducted P wave just behind the QRS complex. An electrophysiological study revealed antidromic atrioventricular tachycardia involving an atrioventricular connection with decremental conduction as the anterograde limb and normal atrioventricular node as the retrograde limb. During constant pacing from the high right atrium (HRA) at the cycle length (CL) of 600 ms, the QRS configurations were not identical to those during the wide QRS tachycardia or constant pacing at the CL of less than 500 ms. The process by which this arborized atrioventricular accessory pathway with the Mahaim fibers physiology was interrupted by radiofrequency catheter ablation is described. Radiofrequency energy was delivered to the site recording a Mahaim potential at the tricuspid annulus during constant pacing from the HRA at the CL of 429 ms. The stimulus-QRS interval gradually shortened as it reached the power plateau without changing the preexcited QRS configuration. Shortening of the conduction time over the Mahiam pathway might have resulted in changing of the propagation from a slow to fast conduction zone or acceleration in response to thermal effect in a node-like structure on the atrial insertion site.     

Role of the short isoform of myosin light chain kinase in the contraction of cultured smooth muscle cells as examined by its down-regulation

GbaSM-4 cells, smooth muscle cells derived from brain basilar artery, which express both 210-kDa long and 130-kDa short isoforms of myosin light chain kinase (MLCK), were infected with an adenovirus vector carrying a 1.4-kb catalytic portion of MLCK-cDNA in an antisense orientation. Western blot analysis showed that the expression of short MLCK was depressed without affecting long MLCK expression. The contraction of the down-regulated cells was measured by the cell-populated collagen-fiber method. The tension development after stimulation with norepinephrine or was depressed. The additional infection of the down-regulated cells with the adenovirus construct containing the same insert in a sense direction rescued not only the short MLCK expression but also contraction, confirming the physiological role of short MLCK in the contraction. To examine the role of long MLCK in the residual contraction persisting in the short MLCK-deficient cells, long MLCK was further down-regulated by increasing the multiplicity of infection of the antisense construct. The additional down-regulation of long MLCK expression, however, did not alter the residual contraction, ruling out the involvement of long MLCK in the contractile activity. Further, in the cells where short MLCK was down-regulated specifically, the extent of phosphorylation of 20-kDa myosin light chain (MLC20) after the agonist stimulation was not affected. This finding suggests that there are additional factors to MLC20 phosphorylation that contribute to regulate smooth muscle contraction.     

Evidence of involvement of cytotoxic antibodies directed against patient's HLA class II produced by transfused donor-derived B cells in post-transfusion graft-versus-host disease

Post-transfusion graft-versus-host disease (PTGVHD) is one of the most severe side-effects of blood transfusion. To characterize the effector cells causing this disease, we cloned lymphocytes from a PTGVHD patient's peripheral blood. T-cell and B-cell clones were established, the origins of which were proven to be transfused donor lymphocytes. It was found that the B cells produced IgG that mediated complement-dependent cytotoxicity to the cells bearing the patient's HLA class II genotype. Our results suggest, for the first time, the involvement of B-cell-produced cytotoxic antibodies directed against patient's HLA class II in the pathogenesis of PTGVHD.     

Allogeneic marrow transplantation for refractory anemia: a comparison of two preparative regimens and analysis of prognostic factors

From 1990 to 1993 we performed a prospective study of busulfan (16 mg/kg) and cyclophosphamide (120 mg/kg) in 30 patients with refractory anemia (RA) undergoing related (n = 17) or unrelated (n = 13) donor marrow transplantation. Nineteen patients survive disease free (63% 3- year actuarial disease-free survival [DFS]) and no patient relapsed. These results were compared to those of 38 historical controls with RA treated with cyclophosphamide and total body irradiation, of whom 22 are disease-free survivors and 1 relapsed. After correcting for significant variables between the two treatment groups, we found no statistically significant difference in outcome based on preparative regimen. Combining data from these 68 patients plus 2 additional patients with RA treated before 1993 with busulfan and cyclophosphamide, we identified four variables independently associated with improved survival: younger age, shorter disease duration, lower neutrophil count pretransplant, and lower hematocrit pretransplant. We also found that 15 patients 40 to 55 years of age had a 46% 3-year actuarial DFS and 26 patients receiving unrelated or mismatched related donor marrow had a 50% 3-year actuarial DFS. We conclude that there does not appear to be any significant difference in outcome based on preparative regimen in this patient population. In addition, allogeneic bone marrow transplantation may be a reasonable approach to therapy of RA early after diagnosis. However, whether early intervention with transplantation prolongs survival over that expected without transplantation cannot be ascertained with certainty from available data.     

Acute myocardial infarction with patent infarct-related artery: selection of treatment based on qualitative analysis of coronary angiograms during the acute phase

To evaluate the benefit of emergency coronary angioplasty (PTCA) among patients with acute myocardial infarction having patent infarct-related arteries, we investigated 104 patients who received thrombolysis and/or PTCA within 24 hrs after onset of symptoms. The morphology of coronary artery lesions was qualitatively assessed by angiography and categorized as symmetrical or asymmetrical narrowing with smooth margins (S-group, 72 cases) and asymmetrical narrowing in the form of convex intraluminal obstruction representing a thrombus (T-group, 32 cases). Soon after intervention, angiographic success (residual stenosis less than 75%) was achieved in 85% with PTCA (92% in the T-group vs 82% in the S-group) and in 29% without PTCA (53% vs 16%). At hospital discharge, the figures were 82% with PTCA (75% vs 87%) and 43% without PTCA (73% vs 30%). The incidence of re-infarction and/or total occlusion of the infarct-related artery was 9% with PTCA in both the T- and S-groups but 26% in those without PTCA (6% in the T-group vs 31% in the S-group). These data suggest that in patients with patient infarct-related arteries and severe original stenosis, PTCA has an advantage over thrombolysis alone. Qualitative analysis of coronary morphology by angiography provides a framework for selecting adequate therapy.