Proteolysis of platelet glycoprotein Ib by plasmin is facilitated by plasmin lysine-binding regions

We have characterized the effects of plasmin on glycoprotein Ib (GpIb), a platelet membrane receptor for von Willebrand factor (vWF), and on glycocalicin, a fragment of the alpha chain of GpIb that contains the vWF-binding region. The addition of 4.5 X 10(-7) mol/L plasmin to washed platelets caused a time-dependent decrease in ristocetin- induced, vWF-dependent platelet agglutination. epsilon-Aminocaproic acid (EACA) inhibited plasmin release of glycocalicin-related antigen from washed platelets and preserved vWF-dependent platelet agglutination, thus indicating that the lysine-binding sites on plasmin facilitated its degradation of GpIb. To demonstrate a direct interaction between plasmin and the vWF-binding region of GpIb we incubated purified glycocalicin with plasmin. Plasmin degraded the glycocalicin into two small carbohydrate-poor peptides and into a larger carbohydrate-rich fragment. EACA was able to inhibit plasmin- mediated degradation of glycocalicin in a concentration-dependent fashion. These studies indicated that plasmin degradation of GpIb was due to a direct interaction between plasmin and GpIb and that this effect was mediated by the lysine-binding region of the plasmin molecule.     

Infraocclusion of primary molars: a histologic study

In order to analyze the occurrence and character of ankylosis in primary molars in infraocclusion, 102 primary molars, 62 in infraocclusion and 40 in normal position, in children aged 3–17yr, were studied histologically. Ankylosis was demonstrable in most of the infraoccluded teeth while ankylosis was not found in teeth with normal positions. The ankylosis was always located at the inner root surface. Progression of the resorption of the root with age was seen in both group of teeth. In teeth of younger children, in contrast to teeth of older children, the ankylosis was never found in the cervical portion of the roots. In the mandible, a thicker buccal marginal bone crest could be found in infraoccluded teeth than in teeth in normal position. Bone biopsies revealed no pathologic changes. Pulps ol infraoccluded teeth more often demonstrated degenerative changes like fibrosis and calcifications. It is suggested that ankylosis is a local phenomenon, most likely due to developmental disturbances of the periodontium, and that ankylosis in infraoccluded primary molars is not a static condition but part of an ongoing process during root resorption.     

Aneurysms of the right ventricular outflow tract after tetralogy of Fallot repair: role of radiology

Eight patients with aneurysms of the right ventricular outflow tract patch following tetralogy of Fallot repair were found to have residual distal obstructions. The site of such an obstruction must be carefully documented preoperatively because failure to relieve significant distal obstruction may result in recurrent aneurysm formation. Chest radiography; echocardiography, including Doppler analysis; and cardiac catheterization, including angiocardiography, each have a role in the detection and evaluation of this complication.     

Contrast medium-induced adverse reactions: economic outcome

Because the cost of managing an expected greater number of adverse reactions when high-osmolality contrast media (HOM) are used could offset the higher material cost of low-osmolality contrast media (LOM), a prospective study was done of 795 inpatients undergoing any of four procedures involving intravascular injection of HOM: cardiac catheterization, peripheral angiography, head computed tomography (CT), or body CT. The resources used in managing HOM-induced adverse reactions were measured, and the costs of these resources were estimated. Four hundred five patients (51%) had adverse reactions. Reactions were grouped into three classes according to their severity. Class 1 (mild) reactions occurred in 358 patients (45%), class 2 (moderate) reactions occurred in 44 patients (6%), and class 3 (severe) reactions occurred in three patients (0.4%). Ninety-nine patients (12%) consumed resources as a result of an adverse reaction. The average cost of these resources per patient undergoing examination was $1.07 to the radiology department, $5.83 to the hospital, and $12.93 to a charge-paying insurer. Mean (+/- standard deviation) cost to the hospital for managing class 1, class 2, and class 3 reactions were $2.52 +/- $5.33, $24 +/- $54, and $910 +/- $749, respectively. By comparison, the difference in material cost of HOM versus LOM ranged from $93 for body CT to $179 for cardiac catheterization. Even if LOM were to induce no adverse reactions, the increased material cost associated with universal substitution of LOM for HOM would be greater than the expected cost of managing adverse reactions when HOM are used.     

Interventional radiology: reflections and expectations. The 1985 Eugene P. Pendergrass new horizons lecture

The history and current practice of interventional radiology are reviewed. Interventional radiology is considered a subspecialty of diagnostic radiology that involves the use of a variety of percutaneous techniques to treat a spectrum of vascular and nonvascular diseases. It is physician intensive and requires a commitment to patient care analogous to that in surgery. Still considered in its infancy, interventional radiology should prosper and undergo continued growth over the next several decades.     

川崎氏病的诊治进展

目的：本文详细阐述了关于川崎氏病诊治的最新进展。方法：查阅近10年来国内外关于川崎氏病的相关文献，并进行了详细的讨论。结果：川崎氏病的诊治进展包括相关特征、临床分期、不常见表现、实验室和免疫学特征、心血管方面的表现、病理学及治疗等方面。结论：川崎氏病是儿童获得性心脏病最常见的原因，病因尚未确定，可并发不同程度的冠状动脉疾病。特异性治疗及有效的预防有待于病因和发病机制的确立。     

Paranasal sinus hemorrhage: evaluation with MR imaging

Computed tomography (CT) and magnetic resonance (MR) imaging were performed in ten patients with paranasal sinus hemorrhage after trauma. Acute or subacute hemorrhage was detected on MR images by using T1- and T2-weighted imaging to identify the chemical state of the blood and to differentiate blood from mucosal thickening and sinus effusion. Surgical proof of intrasinus hemorrhage was obtained in only two cases. Displaced fractures, associated cerebral contusions, and traumatic encephalocele were well shown on MR imaging. Nondisplaced and minimally displaced fractures were better evaluated with CT.