Biomedical subjects
Publications and source records attributed to P T Naylor.
Dislocation of the tibiotalar joint without associated fracture is rare. We have presented a case of open anterolateral ankle dislocation with complete ligamentous disruption. In contrast to reports that internal fixation is not required to maintain reduction of tibiotalar joint dislocation, we found this dislocation to be grossly unstable, requiring both a syndesmotic screw and a calcaneotalotibial transfixing pin for stabilization.
Musculoskeletal infection is extraordinarily resistant to treatment. Bacterial colonization is discussed as well as host defense systems and antibiotic resistance.
Whether or not bacterial populations are massively enclosed in slime, it appears that antibiotic resistance, when compared to suspension organisms, is related to surface adhesion and to the specific material of the substratum. These findings are of significance in the understanding and treatment of biomaterial-localized infections.
Explore the source record for details and available documents.
Osteomyelitis and intra-articular infection are septic diseases that present pathogenic features characteristic of molecular mechanisms involving adhesion to substrata. In this review, mechanisms of microbial adhesion to bone and cartilage as substrata are presented and related to host tissue response and to antibiotic treatment.
The MBCs of nafcillin, vancomycin, gentamicin and daptomycin (LY146032) were determined for three clinical isolates of coagulase-negative staphylococci grown in suspension and adherent to biomaterials. Strains studied were the slime-producing strain Staphylococcus epidermidis RP-12 (ATCC 35983), S. hyicus SE-360, and the non-slime-producing strain S. hominis SP-2 (ATCC 35982). All three strains were allowed to colonize surgical-grade disks of stainless steel, polymethylmethacrylate, and ultrahigh-molecular-weight polyethylene for 24 h, and the disks were then exposed to various concentrations of antibiotics for 24 h. Surviving adherent bacteria were mechanically dislodged from the disks and quantitated by standard broth dilution plating techniques. Biomaterial-adherent RP-12 and SE-360 yielded approximately 10 times more CFU per disk than non-slime-producing SP-2 did. For all organisms, 10 times more bacteria bound to polymethylmethacrylate disks than to the other biomaterials. In general, bacteria adherent to biomaterials exhibited greater resistance to antibiotics than the same strains in suspension did. Resistance was independent of bacterial slime-producing characteristics and was related to the biomaterial colonized.
To establish the requirements for a potential subunit vaccine against herpes simplex virus (HSV), we analyzed the effects on immunogenicity of incorporating detergent-extracted glycoprotein-enriched HSV type 1 (HSV-1) antigens into liposomes alone or with the adjuvant lipid A. Incorporating HSV-1 antigens into liposomes enhanced their immunogenicity for antibody production as detected by radioimmunoassay. Antibody levels to free and liposome-bound antigens were enhanced by administering lipid A as an adjuvant. The maximum immunogenic effect was obtained by incorporating lipid A into liposomes containing the HSV-1 proteins. Such liposomes induced secondary antibody responses higher than those engendered by virus infection. Whereas infectious virus induced cell-mediated immunity detectable by the delayed-type hypersensitivity reactions and cytotoxic T lymphocyte production, none of the liposome preparations induced cell-mediated immunity.
The immunogenicity of inactivated herpes simplex virus type 1 (HSV-1) antigens incorporated into liposomes was measured by their ability to induce secondary anti-HSV-1 specific cytotoxic T lymphocyte (CTL) responses in splenocyte cultures from virus-primed mice. Such virus-specific CTL could be induced provided the liposomes contained virus along with plasma membrane antigen of the same H-2 type as that of the virus-primed responser cells. Responses did not occur in cultures stimulated with liposomes containing only viral antigens or with a mixture of liposomes composed respectively of lipid and virus with those composed of lipid and plasma membrane proteins. Moreover F1 responder cells stimulated with liposomes composed of virus and plasma membrane protein of one of the parental haplotypes produced CTL restricted in their cytotoxicity to infected targets of the same haplotype as was used in the liposome. These results show that liposomes can be used to induce anti-HSV-1 CTL with inactivated viral antigens but recognition of both viral and H-2 antigen is required for this process to occur in vitro. The implications of our findings to the preparation of subunit vaccines against HSV-1 are briefly discussed.