Interventional Efforts to Reduce Psychological Distress After Orthopedic Trauma: A Systematic Review

HSS Journal ® - Unanticipated severe injury to part of the musculoskeletal system, referred to as orthopedic trauma, can be debilitating. It can also be accompanied by equally debilitating...     

Isolation and characterization of amyloid protein AA in the Abyssinian cat

Amyloid fibrils were isolated by extraction in deionized water from the kidneys of an Abyssinian cat with familial renal amyloidosis. The fibrils were suspended in a buffer containing 6 M guanidine hydrochloride and reduced and alkylated using dithiothreitol and iodoacetid acid. The resulting amyloid fibril subunit protein was isolated by chromatography on a column of Sepharose CL6B. It was fragmented using cyanogen bromide, and the resultant peptides were separated by reverse phase high performance liquid chromatography. The protein was characterized by determination of the amino acid sequence of the cyanogen bromide fragments using a Beckman 890C sequencer. The primary structure of this amyloid fibril subunit protein showed strong homology with amyloid protein AA found in man and animals with spontaneous and experimentally induced reactive systemic amyloidosis. This study confirms the reactive nature of familial renal amyloidosis in the Abyssinian cat and suggests that this disease may be a valuable spontaneous animal model for the study of familial Mediterranean fever in man.     

Endovascular Infections Caused by Methicillin-Resistant Staphylococcus aureus Are Linked to Clonal Complex-Specific Alterations in Binding and Invasion Domains of Fibronectin-Binding Protein A as Well as the Occurrence of fnbB

Endovascular infections caused by Staphylococcus aureus involve interactions with fibronectin present as extracellular matrix or surface ligand on host cells. We examined the expression, structure, and binding activity of the two major S. aureus fibronectin-binding proteins (FnBPA, FnBPB) in 10 distinct, methicillin-resistant clinical isolates from patients with either persistent or resolving bacteremia. The persistent bacteremia isolates (n = 5) formed significantly stronger bonds with immobilized fibronectin as determined by dynamic binding measurements performed with atomic force microscopy. Several notable differences were also observed when the results were grouped by clonal complex 5 (CC5) strains (n = 5) versus CC45 strains (n = 5). Fibronectin-binding receptors on CC5 formed stronger bonds with immobilized fibronectin (P < 0.001). The fnbA gene was expressed at higher levels in CC45, whereas fnbB was found in only CC5 isolates. The fnbB gene was not sequenced because all CC45 isolates lacked this gene. Instead, comparisons were made for fnbA, which was present in all 10 isolates. Sequencing of fnbA revealed discrete differences within high-affinity, fibronectin-binding repeats (FnBRs) of FnBPA that included (i) 5-amino-acid polymorphisms in FnBR-9, FnBR-10, and FnBR-11 involving charged or polar side chains, (ii) an extra, 38-amino-acid repeat inserted between FnBR-9 and FnBR-10 exclusively seen in CC45 isolates, and (iii) CC5 isolates had the SVDFEED epitope in FnBR-11 (a sequence shown to be essential for fibronectin binding), while this sequence was replaced in all CC45 isolates with GIDFVED (a motif known to favor host cell invasion at the cost of reduced fibronectin binding). These complementary sequence and binding data suggest that differences in fnbA and fnbB, particularly polymorphisms and duplications in FnBPA, give S. aureus two distinct advantages in human endovascular infections: (i) FnBPs similar to that of CC5 enhance ligand binding and foster initiation of disease, and (ii) CC45-like FnBPs promote cell invasion, a key attribute in persistent endovascular infections.     

Examining the perceived impact of an ethics workshop on interprofessional values and teamwork

Interprofessional education (IPE) is a vital component of healthcare education yet challenges to implementation persist. This study aimed to evaluate the perceived impact of an ethics-based IPE workshop designed for professional phase healthcare students enrolled in athletic training, health management systems, occupational therapy, physical therapy, physician assistant studies, and speech-language pathology programmes at one university. A pre/post-test cohort study was conducted to evaluate the impact of the workshop on interprofessional values and teamwork. Findings from the 61 students who completed both pre- and post-programme evaluation surveys suggest that the ethics-based workshop was successful in improving perceived confidence as related to the workshop objectives and strengthened positive perceptions of IPE as evaluated by the Student Perceptions of Interprofessional Clinical Education-Revised (SPICE-R). Analysis of responses to open-ended reflection questions after the workshop suggest that student participants perceived changes in understanding related to multiple areas of IPE. These results suggest that an ethics-based workshop using case-based collaborative pedagogy may be an effective mechanism for delivery of IPE-oriented information resulting in greater student confidence and understanding of IPE competencies.     

Do learning style and learning environment affect learning outcome?

This study compared learning outcomes of students with different learning styles, as identified by the Kolb Learning Style Inventory indicators, in a traditional in-class environment with those taking the same course via distance education. The above-average scores were evenly distributed, 47% of the in-class group and 43% of the distance group. For three of the four learning styles, there was no relationship to learning outcome or environment. The Diverger group did show a relationship with above-average scores in the distance group (83%). The findings support that the classroom or distance environment did not influence learning outcome. Learning style did not appear to affect learning outcome in either group, except that the Diverger learning style may have a positive relationship to learning in the distance environment.     

Tissue distribution of amyloid deposits in Abyssinian cats with familial amyloidosis

The tissue distribution of amyloid deposits was studied in 15 related Abyssinian cats with familial amyloidosis. There was interstitial medullary amyloidosis in the kidneys of all 15 cats but only 11 had detectable glomerular involvement. The thyroid glands, stomach and colon were affected in all cats examined. Most of the cats also had amyloid deposits in the small intestine, spleen, heart, adrenals, pancreas, liver, lymph nodes and bladder. In 50 per cent or fewer of the cats examined, there was involvement of the parathyroids, lung and gonads. The central nervous system was not involved in any of the 3 cats evaluated. In 8 of the cats, no concurrent inflammatory disease could be detected. The tissue distribution of amyloid deposits resembled that found in other breeds of domestic cats with systemic amyloidosis. Despite the wide tissue distribution of amyloid deposits, clinical signs were related to renal amyloidosis. Familial amyloidosis in the Abyssinian cat may represent a valuable spontaneous animal model for the study of Familial Mediterranean Fever in man and the pathogenesis of reactive amyloidosis in general.     

Identification and characterization of amyloid protein AA in spontaneous canine amyloidosis

Amyloid fibrils were isolated from kidney tissue of a dog that presented with renal failure due to spontaneous amyloidosis. This fibril material was reduced, alkylated and chromatographed on a column of Sepharose CL6B. A major retarded fraction, when subjected to amino acid sequencing, demonstrated a blocked amino terminus. The isolated protein was then degraded with cyanogen bromide, and the resultant three peptides were isolated by high-pressure liquid chromatography. The amino acid sequence of one peptide corresponded to the sequence of human amyloid protein AA from position 17 to 23. A second peptide gave an amino acid sequence homologous to the published human protein AA sequence starting with position 24. Although a high degree of homology between canine and human AA is seen, the blocked amino terminus is similar to the AA protein of mink. These data show that spontaneous canine amyloid is analogous to human reactive (secondary) amyloid and, therefore, may aid in defining mechanisms of human amyloid pathogenesis.     

A unique insertion in the primary structure of bovine amyloid AA protein

Amyloid fibrils were isolated from kidney tissue of a cow afflicted with renal failure caused by spontaneous reactive amyloidosis. These fibrils were reduced and alkylated, and the amyloid subunit protein was isolated on a column of Sepharose CL6B. The protein was fragmented with both trypsin and Staphylococcus protease, and the resultant peptides were separated by high-performance liquid chromatography. Sequence analysis gave the complete primary structure of the protein with overlaps of the tryptic peptides confirmed by the Staphylococcus protease peptides. Comparison of the bovine amyloid A (AA) amino acid sequence with human protein AA demonstrates complete invariability from human position 33 to 45 and a very high degree of homology from positions 16 to 29 and 46 to 63. These data indicate that these portions of the molecule may be significant factors in amyloid fibrilogenesis. The bovine AA protein shows a blocked amino terminus, as is the case with the dog and the cat AA proteins. In addition, this protein contains an insertion of nine amino acid residues between human positions 69 and 70. The existence of an additional six residues after position 76 makes the bovine AA an unusually large 90 amino acid peptide. These findings point to a high tolerance for mutation in the carboxyl end of the molecule.     

Polymorphisms in fibronectin binding protein A of Staphylococcus aureus are associated with infection of cardiovascular devices

Medical implants, like cardiovascular devices, improve the quality of life for countless individuals but may become infected with bacteria like Staphylococcus aureus. Such infections take the form of a biofilm, a structured community of bacterial cells adherent to the surface of a solid substrate. Every biofilm begins with an attractive force or bond between bacterium and substratum. We used atomic force microscopy to probe experimentally forces between a fibronectin-coated surface (i.e., proxy for an implanted cardiac device) and fibronectin-binding receptors on the surface of individual living bacteria from each of 80 clinical isolates of S. aureus. These isolates originated from humans with infected cardiac devices (CDI; n = 26), uninfected cardiac devices (n = 20), and the anterior nares of asymptomatic subjects (n = 34). CDI isolates exhibited a distinct binding-force signature and had specific single amino acid polymorphisms in fibronectin-binding protein A corresponding to E652D, H782Q, and K786N. In silico molecular dynamics simulations demonstrate that residues D652, Q782, and N786 in fibronectin-binding protein A form extra hydrogen bonds with fibronectin, complementing the higher binding force and energy measured by atomic force microscopy for the CDI isolates. This study is significant, because it links pathogenic bacteria biofilms from the length scale of bonds acting across a nanometer-scale space to the clinical presentation of disease at the human dimension.