The application of PRP for large to massive rotator cuff repairs significantly improved structural outcomes, as evidenced by a decreased retear rate and increased CSA of the supraspinatus compared with repairs without PRP augmentation. While there was no significant difference in clinical outcomes except the overall shoulder function after 1-year follow-up, better structural outcomes in the PRP group might suggest improved clinical outcomes at longer term follow-up.

Compared with repairs without PRP augmentation, the current PRP preparation and application methods for medium to large rotator cuff repairs significantly improved the quality, as evidenced by a decreased retear rate and increased CSA of the supraspinatus, but not the speed of healing. However, further studies may be needed to investigate the effects of PRP on the speed of healing without risking the quality.

Antibodies against the malaria vaccine candidate apical membrane antigen-1 (AMA-1) can inhibit invasion of merozoites into RBC, but antigenic diversity can compromise vaccine efficacy. We hypothesize that polymorphic sites located within inhibitory epitopes function as antigenic escape residues (AER). By using an in vitro model of antigenic escape, the inhibitory contribution of 24 polymorphic sites of the 3D7 AMA-1 vaccine was determined. An AER cluster of 13 polymorphisms, located within domain 1, had the highest inhibitory contribution. Within this AER cluster, antibodies primarily targeted five polymorphic residues situated on an ␣-helical loop. A second important AER cluster was localized to domain 2. Domain 3 polymorphisms enhanced the inhibitory contribution of the domain 2 AER cluster. Importantly, the AER clusters could be split, such that chimeras containing domain 1 of FVO and domain 2 ؉ 3 of 3D7 generated antisera that showed similarly high level inhibition of the two vaccine strains. Antibodies to this chimeric protein also inhibited unrelated strains of the parasite. Interstrain AER chimeras can be a way to incorporate inhibitory epitopes of two AMA-1 strains into a single protein. The AER clusters map in close proximity to conserved structural elements: the hydrophobic trough and the C-terminal proteolytic processing site. This finding led us to hypothesize that a conserved structural basis of antigenic escape from anti-AMA-1 exists. Genotyping high-impact AER may be useful for classifying AMA-1 strains into inhibition groups and to detect allelic effects of an AMA-1 vaccine in the field.Plasmodium ͉ apical membrane antigen-1 ͉ invasion A ntigenic diversity has been implicated in the failure of several licensed and test vaccines (1). The ''Combination B'' malaria vaccine, containing merozoite surface protein-2 (msp-2) of Plasmodium falciparum 3D7 strain as one of its components, successfully reduced the prevalence of the 3D7 msp-2 genotype but had no impact on the prevalence of parasites with the FC27 msp-2 genotype (2). Understanding the molecular basis of strain specificity and the resulting antigenic escape is therefore important for vaccine development.Apical membrane antigen-1 (AMA-1) is one of the leading malaria vaccine candidates. Immunization with AMA-1 induces antibodies that inhibit invasion, conferring protection in animals (3). P. falciparum AMA-1 vaccines based on 3D7 and FVO strain are currently in efficacy human trials (4, 5). Despite the strong preclinical evidence favoring its vaccine candidacy, there are Ͼ60 polymorphic sites on AMA-1 protein. Among the 50 Thai isolates sequenced, there were 27 haplotypes. Similarly, of the 50 Nigerian sequences there were 45 haplotypes, and of the 68 Papuan New Guinean sequences there were 27 haplotypes (6-8).The strain variability of AMA-1 is a cause of concern to vaccinologists.Strain-specific differences are reported among field antisera by ELISA (9, 10) or by using a functional assay of parasite growth and invasion inhibition (GIA) (11). Al...