Non-Q- and Q-wave infarction after thrombolytic therapy with intravenous streptokinase for chest pain and anterior ST-segment elevation

The clinical features of patients treated with streptokinase for chest pain and anterior ST-segment elevation who subsequently develop non-Q-wave infarction are unknown. Of the 75 consecutive patients who initially presented with chest pain and ST-segment elevation in the anterior leads (V1-V6, I, aVL) and were treated with intravenous streptokinase (time from symptoms to treatment averaged less than 3 hours), 32 (43%) developed a non-Q-wave and 43 (57%) a Q-wave myocardial infarction. Twenty seven of 32 patients (84%) from the non-Q-wave group and 39 of 43 (91%) from the Q-wave group were studied by angiography at 5.16 +/- 2.88 days after the onset of myocardial infarction. Left ventricular end-diastolic pressure was 13 +/- 6 vs 20 +/- 7 mm Hg (p less than 0.001), left ventricular ejection fraction was 60 +/- 8 vs 49 +/- 14% (p less than 0.001) and the infarct vessel patency rate was 85 vs 72% (p = 0.44) in patients with a non-Q versus a Q-wave infarction, respectively. In summary, when patients presenting with chest pain and ST-segment elevation are treated with streptokinase, a significant portion of these symptoms will evolve into a non-Q-wave infarction. Patients with a non-Q-wave infarction will have a better preserved left ventricular function than patients who develop a Q-wave infarction. This suggests the need for equal distribution of such patients in randomized trials of thrombolytic therapy for acute myocardial infarction to avoid misinterpreting data between groups.     

Feasibility of universal home haemodialysis with simplified techniques

Maintenance haemodialysis was offered to an unselected series of patients presenting with end-stage renal disease between 1975 and 1982. Of the initial 283 patients, 274 started on haemodialysis, and 89% of these were alive and available for follow-up beyond the first 3 months of treatment. 98% of the latter eventually achieved permanent home haemodialysis with a system using simplified dialysis equipment and procedures, together with training methods designed to reinforce patient motivation. Universal home haemodialysis is now feasible when appropriate techniques are used.     

Protein kinase A type I and type II define distinct intracellular signaling compartments

Protein kinase A (PKA) is a key regulatory enzyme that, on activation by cAMP, modulates a wide variety of cellular functions. PKA isoforms type I and type II possess different structural features and biochemical characteristics, resulting in nonredundant function. However, how different PKA isoforms expressed in the same cell manage to perform distinct functions on activation by the same soluble intracellular messenger, cAMP, remains to be established. Here, we provide a mechanism for the different function of PKA isoforms subsets in cardiac myocytes and demonstrate that PKA-RI and PKA-RII, by binding to AKAPs (A kinase anchoring proteins), are tethered to different subcellular locales, thus defining distinct intracellular signaling compartments. Within such compartments, PKA-RI and PKA-RII respond to distinct, spatially restricted cAMP signals generated in response to specific G protein-coupled receptor agonists and regulated by unique subsets of the cAMP degrading phosphodiesterases. The selective activation of individual PKA isoforms thus leads to phosphorylation of unique subsets of downstream targets.     

Stem cell niches as clinical targets: the future of anti-ischemic therapy?

This article provides context for the research presented by Napoli et al., reported in this journal. Treatment strategies that target stem cell niches are promising avenues for stimulating inducible angiogenesis in many vascular diseases, such as diabetes mellitus and atherosclerosis. Here we discuss the study carried out by Napoli and colleagues--an analysis of the effects of parathyroid hormone on the vascular stem cell niche in peripheral ischemia. Napoli et al. demonstrate that parathyroid hormone administered in combination with granulocyte colony-stimulating factor induces angiogenesis in a hindlimb ischemia mouse model. This treatment seems to mobilize and localize endothelial cell progenitors specifically to ischemic vascular cell beds. We explore the mechanisms through which the multiple cells within the vascular niche respond to ischemia. The interaction between parathyroid hormone and granulocyte colony-stimulating factor in humans is also discussed. Further assessment is needed to elucidate the factors involved in migration and differentiation of endothelial cell progenitors in ischemia-damaged tissues.     

Novel imaging techniques of the esophagus enhancing safety of left atrial ablation

This report describes different imaging techniques of the esophagus in four patients during radiofrequency catheter ablation of atrial fibrillation in the left atrium. A novel use of a mixture of barium cream and gadolinium diglutamate allowed esophageal imaging during magnetic resonance angiography of the left atrium and pulmonary veins. Barium cream used during computer tomography angiographic imaging of the left atrium and pulmonary veins allowed esophageal imaging. The esophagus was also imaged with an electroanatomic mapping system. Esophageal and left atrial imaging helped to avoid catheter ablation in left atrial tissue overlapping the esophagus.     

Epstein-Barr Virus-Associated Membrane-Reactive Antibodies During Long Term Survival After Burkitt''s Lymphoma

Antibodies to Epstein-Barr virus associated cell membrane antigens persisted or slowly decreased during prolonged uncomplicated survival of patients with Burkitt's lymphoma in remission. Serum was sampled from four patients within 6 months before recurrence occurring after the first year and preceded by remission during more than 6 months. Rapid and significant decreases of the antibodies before clinical recognition of the recurrences were found in three patients. The fourth patient had slowly increasing titers before relapse. Immune stimulant treatment during remission, with BCG (Bacille Calmette Guérin vaccine) or BCG + Bordetella pertussis, temporarily increased the antibody levels. Possible mechanisms for the observed titer changes before recurrence are discussed.     

High normal serum levels of C3 and C1 inhibitor,two acute-phase proteins belonging to the complement system,occur more frequently in patients with Crohn's disease than ulcerative colitis

Few data are available on measurements of serum concentrations of complement proteins in inflammatory bowel disease (IBD). Therefore we measured serum levels of C3, C4, and C1-esterase inhibitor (C1-INH) as well as C-reactive protein (CRP) in 167 patients with Crohn's disease (CD) and 111 patients with ulcerative colitis (UC). Median serum concentrations of C3 and C1-INH were significantly higher in CD than in UC. According to multiple logistic regression analysis adjusted to age, sex, activity of disease, and presence of extraintestinal manifestations, IBD patients with high-normal (128%, 75th percentile ) C1-INH concentrations had significantly (0.0275) higher odds ratio to have a diagnosis of CD than UC. Patients with high-normal C3 (1.40 g/liter) and high (20 mg/liter) CRP concentrations had an even higher odds ratio of a CD diagnosis (P = 0.0132). Our findings indicate that measurement of C3, C1-INH, and CRP can be used as an additional marker to pANCA/ASCA for distinguishing patients with CD and UC.