Thrower's fracture: a comparison of two presentations of a rare fracture

We report two similar rare types of fracture of the lower end of the humerus sustained in fit young adults while throwing a ball. Both cases were seen within 1 week in a busy accident and emergency (A&E) department. The types of fracture in each case are unusual and, in the past, have been attributed to fatigue or to a repetitive strain pattern.     

Development of the quality of life in epilepsy inventory

We developed an instrument to measure health-related quality of life (HRQOL) in epilepsy. A 99-item inventory was constructed from the RAND 36-Item Health Survey (generic core), with 9 additional generic items, 48 epilepsy-targeted items, and 6 other items concerning attitudes toward epilepsy and self-esteem. We administered the 99-item inventory to 304 adults with epilepsy at 25 epilepsy centers. Patients and patient-designated proxies completed the inventory and were retested 1-91 days later. A multitrait scaling analysis of these data led to retention of 86 items distributed in 17 multiitem scales (Cronbach's alpha ranged from 0.78 to 0.92). Factor analysis of the 17 multiitem scales yielded four underlying dimensions of health: an epilepsy-targeted dimension, a cognitive factor, mental health, and physical health. Construct validity was supported by significant patient-proxy correlations for all scales and correlations between neuropsychologic tests and self-reported emotional and cognitive function (all p values < 0.05). There were significant negative correlations between the four factor scores derived from the HRQOL scales and neurotoxicity, systemic toxicity, and health care utilization (except for the correlation between mental health factor and health care utilization; all p values < 0.05). Patients who were seizure-free in the preceding year reported better HRQOL for the overall score, three of the four factor scores, and 8 of the 17 scale scores than did patients with a high frequency of seizures. Relative validity analysis showed that the epilepsy-targeted factor and three of its four component scales were more sensitive to categorization of patients by severity of seizure frequency and type than scales tapping physical health, mental health, or cognitive function. These cross-sectional data support the reliability and validity of this measure of HRQOL in epilepsy. The addition of an epilepsy-targeted supplement to the generic core improved the sensitivity to severity of epilepsy. The 86 items included in the field testing were supplemented by three additional items to form the Quality of Life in Epilepsy (QOLIE-89) inventory.     

Rational design of Rhizopus oryzae lipase with modified stereoselectivity toward triradylglycerols

The binding site of sn-1(3)-regioselective Rhizopus oryzae lipase (ROL) has been engineered to change the stereoselectivity of hydrolysis of triacylglycerol substrates and analogs. Two types of prochiral triradylglycerols were considered: 'flexible' substrates with ether, benzylether or ester groups, and 'rigid' substrates with amide or phenyl groups, respectively, in the sn-2 position. The molecular basis of sn-1(3) stereoselectivity of ROL was investigated by modeling the interactions between substrates and ROL, and the model was confirmed by experimental determination of the stereoselectivity of wild-type and mutated ROL. For the substrates, the following rules were derived: (i) stereopreference of ROL toward triradylglycerols depends on the substrate structure. Substrates with 'flexible' sn-2 substituents are preferably hydrolyzed at sn-1, 'rigid' substrates at sn-3. (ii) Stereopreference of ROL toward triradylglycerols can be predicted by analyzing the geometry of the substrate docked to ROL: if the torsion angle phiO3-C3 of glycerol is more than 150 degrees, the substrate will preferably be hydrolyzed in sn-1, otherwise in sn-3. For ROL, the following rules were derived: (i) residue 258 affects stereoselectivity by steric interactions with the sn-2 substituent rather than polar interactions. To a lower extent, stereoselectivity is influenced by mutations further apart (L254) from residue 258. (ii) With 'rigid' substrates, increasing the size of the binding site (mutations L258A and L258S) shifts stereoselectivity of hydrolysis toward sn-1, decreasing its size (L258F and L258F/L254F) toward sn-3.      

Decreased fibrinolytic activity in porcine-to-primate cardiac xenotransplantation

BACKGROUND: One major barrier to successful xenotransplantation is acute vascular rejection, a process pathologically characterized by microvascular thrombosis and diffuse fibrin deposition in transplant blood vessels. This pathologic picture may result from a disturbance in the coagulant or fibrinolytic pathways that regulate normal vascular patency. This study evaluated the regulation of fibrinolytic activity defined by tissue plasminogen activator and plasminogen activator inhibitor-1 as it may exist in the setting of acute vascular rejection. MATERIALS AND METHODS, RESULTS: Serial biopsies from cardiac xenotransplants evaluated by immunofluorescence microscopy demonstrated progressive decreases in tissue plasminogen activator and increases in plasminogen activator inhibitor-1. In vitro studies measuring fibrinolytic activity of cell culture medium from porcine aortic endothelial cells stimulated with human serum or autologous porcine serum revealed that human serum triggered as much as 93% increase in antifibrinolytic activity. CONCLUSIONS: These findings demonstrate that porcine vascular endothelial cells change toward an antifibrinolytic state following stimulation with human xenoreactive antibodies and complement. The shift is at least partly explained by an increased ratio of plasminogen activator inhibitor-1 to tissue plasminogen activator, and is at least in part mediated by the activation of complement. This increased antifibrinolytic activity may contribute to the thrombotic diathesis seen in acute vascular rejection in pig-to-primate xenografts.