Structural polymorphism of glycophorins demonstrated by immunoblotting techniques

We have explored the polymorphism of the glycophorin system in the human erythrocyte membrane using the immunoblotting techniques and examining 52 individuals selected without prior bias as to their serologic state and ten documented serologic variants of M, N, S, s blood group system. Polyclonal antisera to alpha glycophorin and to alpha glycophorin CNBr carboxyl terminal fragment C (residues 82-131) and M and N specific monoclonal antibodies (MoAbs) were used. The first two reagents detect specific regions of the alpha glycophorin molecule and all electrophoretically resolved species of glycophorins immunologically related to alpha and delta glycophorins (delta glycophorin, [alpha-delta] hybrids and other glycophorins with an alteration in the carboxyl terminal segment); the M and N MoAbs identified the glycophorin species containing or lacking the M or N determinant in the amino terminal octapeptide structures. We find that immunoblotting confirmed in all cases the serologically determined phenotype; we also find that polymorphic forms of the glycophorin system are relatively infrequent; immunoblotting, independent from serologic testing, was capable of detecting five mutants, two most likely S-s-U-phenotypes; a new glycophorin species was detected in normal red cells with both antiglycophorin and antipeptide C sera, which is not evident with MoAbs; immunoblots of known glycophorin variants (En(a-), U-, Mg, Mi I, II, III, V, and Sta) confirmed but also extended our knowledge of the abnormal glycophorins involved; and the He+ and Wrb(-) cells showed normal patterns.     

Reproducibility of transesophageal echocardiography in evaluating aortic atheroma in stroke patients

Although transesophageal echocardiography (TEE) is a well-established tool in delineating the cardiac and aortic sources of emboli in stroke patients, its reproducibility in detecting aortic atherosclerosis (AA) that may lead to stroke is not well documented. The aim of this study is to demonstrate the inter- and intra-observer agreement in diagnosing AA based on the TEE study. During the study period, 2 echocardiographers read 32 TEE studies performed on a group of stroke patients. The AA was estimated by measuring the largest atheroma thickness in millimeters (mm). The intra-observers and intraclass correlation coefficients (ICC) were 0.97 and 0.85, respectively, for the 2 TEE observers. The inter-rater ICC coefficient between TEE readers was 0.91. In conclusion, TEE detected AA and defined high proportions of the morphological characteristics of atheroma with good reproducibility among inter and intra-observers.     

Thrombolytic therapy for acute extra-cranial artery dissection: report of two cases.

Extra-cranial arterial dissection accounts for 10% of strokes in young people. Information on safety of thrombolytic administration in this group is limited. The literature, however, does not favor use of thrombolytics for myocardial ischemia when peripheral arterial dissection coexists. Based on the clinical and radiological features, two patients who presented with acute stroke secondary to arterial dissection were considered for thrombolysis. One of them received intra-venous recombinant tissue plasminogen activator (rtPA), and the other patient received intra-arterial rtPA. There were no post thrombolysis complications. This report supports feasibility of administering thrombolytics in acute ischemic strokes resulting from extra-cranial arterial dissection. Future larger studies are necessary to determine the efficacy, safety and long-term outcome in this patient population.