Peripheral blood samples from 313 normal donors were tested for prior human cytomegalovirus (HCMV) infection: 37%, 0.9%, and 43% of the samples were positive by antibody detection, DNA hybridization, and RNA hybridization assays, respectively. An early mRNA, which is transcribed from a HindIII-b fragment of the CMV genome and detected with an antisense RNA probe, can be detected more frequently than antibody and CMV DNA. The early CMV mRNA transcripts can be detected in the peripheral white blood cells in 44% of HCMV-seronegative blood donors. Blood samples that were CMV RNA positive but antibody negative comprised 27% of the tested samples. Whether CMV RNA in donor blood indicates that CMV can be transmitted via blood transfusion must be determined by further studies.
Identity of Treponema pallidum subsp. pallidum polypeptides: Correlation of sodium dodecyl sulfatepolyacrylamide gel electrophoresis results from different laboratoriesAs the first step in a cooperative effort to standardize the identification of the polypeptides of Treponerna pallidum subsp. pallidurn, the sodium dodecyl sulfatepolyacrylamide gel electrophoresis (SDS-PAGE) results obtained in 16 laboratories were compared. Although it was possible to correlate the positions of 16 ofthe major polypeptide bands, the cross-identification of many of the polypeptides was ambiguous, particularly in the low molecular weight range. Two-dimensional electrophoresis provided an improved means of separating and characterizing T.pallidum polypeptides as isolated molecular species. An approach to the unambiguous identification of treponemal polypeptides was outlined which will utilize two-dimensional electrophoresis in combination with specific properties attributable to individual proteins, including reactivity with monoclonal antibodies or monospecific antisera, biochemical and structural properties, and sequence information. To demonstrate the feasibility of this approach, two-dimensional electrophoresis in conjunction with immunoperoxidase staining was used to specifically identify three cloned T.pal1idum proteins. Abbreviations: CIE, crossed immunoelectrophoresis; 2DE, two-dimensional gel electrophoresis; IRS, infected rabbit serum; 2-ME, 2-mercaptoethanol; PBS, phosphate-buffered saline; RIP, radioimmunoprecipitation: SDS-PAGE, sodium dodecyl sulfate-polyacrylamide gel electrophoresis; T, Tween 20 0 VCH Verlagsgesellschaft mbH, D-6940 Weinheim, 1987 0173-0835/87/0202-0077 %02.50/0 S. J. Norris et al. Electrophoresis 1987,8, 77-92 Figure 16. Reactivity of rabbit antiserum directed against cloned antigenTmpC (1301, seeFig. 6)with the 2DEpatternof T.paNidum.Theprocedure wasas described in Fig. 15. (A) Reaction with the TmpC-specific antiserum. (B) Antigenic profile following IRS counterstaining. The antiserum reacted specifically with a single band on the SDS-PAGE pattern (far left) and a single spot at the acid end of the 2DE pattern.Figure 17. Localization of cloned antigen TpD (1301, see Fig. 6) in the 2DE profile of T.pallidum, utilizing a specific rabbit antiserum prepared by affinity chromatography. (A) Reactivity of TpD-specific antiserum. Due to prolonged incubation with the color reagent, background reactivities of the antiserum to TmpC and the major 61 polypeptide were also detectable in this case. (B) Antigenic profile following IRS counterstaining. The positions of TpD and TmpC in the 2D and single dimension SDS-PAGE profiles are indicated by the arrows.
An experimental biodegradable bone cement [poly(propylene fumarate)-methylmethacrylate] (PPF-MMA) has been compared in vivo with polymethylmethacrylate (PMMA) as a carrier agent for local release of antibiotics. This approach is potentially applicable to the treatment of chronic osteomyelitis where the clinical goal is to achieve sustained high concentrations of antibiotics locally in the infected bone. In our experiments, gentamicin- and vancomycin-impregnated cylindrical PMMA and PPF-MMA cement specimens were implanted subcutaneously in rats, and blood and wound fluid samples were obtained over a 2-week period. Antibiotic levels were determined using immunoassays, and microbiologic activity was confirmed with agar diffusion techniques. The biodegradable PPF-MMA cement achieved and maintained considerably higher wound antibiotic levels than did PMMA cement. Vancomycin levels for the PPF-MMA cement were greater than 20 times those for the PMMA cement at all sampling times from 24 h to 14 days. For both cements, the serum antibiotic concentrations remained safely below maximum levels recommended for parenteral therapy. Mechanical testing of the PPF-MMA cement showed that admixture of 3% by weight of antibiotic did not adversely affect material properties. We conclude that this experimental biodegradable bone cement (PPF-MMA) can be used as a carrier to achieve high sustained local levels and low serum levels of antibiotics. Because it is biodegradable and thus does not require a secondary procedure for removal, it has special potential for use in treatment of chronic osteomyelitis.
Treponema pallidum DNA was cloned in a bacteriophage. Clones were screened for expression of Treponema pallidum antigens by an in situ radioimmunoassay on nitrocellulose, with the use of subsequent reactions with syphilitic serum and radioiodinated Staphylococcus aureus protein A. One clone, which gave a strong signal, codes for at least seven antigens that react specifically with human antibodies to Treponema pallidum.
A biodegradable, particulate composite bone cement containing gentamicin and vancomycin was used for both treatment and prophylaxis of Staphylococcus aureus osteomyelitis in rats. Osteomyelitis was established by inoculating S. aureus into holes that were drilled in the proximal tibiae and were filled with polymethylmethacrylate (PMMA) cylinders. The cylinders were left in place for 3 weeks. The infections were serially evaluated by clinical and radiographic examination and by quantitative culture for colony forming units (CFUs) at the time the rats were killed. For treatment, cements containing antibiotic were implanted in animals that had established osteomyelitis and were left in place for an additional 3 weeks. Sites treated with biodegradable cement containing antibiotics exhibited significantly fewer CFUs in comparison with controls (p < 0.01). Sites treated prophylactically with the biodegradable cement developed no infections as evaluated by clinical or radiographic criteria or by quantitative culture. At this relatively early time, no significant difference in therapeutic effectiveness was found when either the biodegradable cement or PMMA was used as a carrier for antibiotics.
CDC frequently affects surgical patients, producing morbidity ranging from mild diarrhea to life-threatening illness. A variety of factors, many of which are associated with intestinal stasis, predispose to the development of CDC.
Acute and chronic osteomyelitis can be difficult to treat by conventional means. Current methods of treatment involve the use of systemic antibiotics, the local implantation of non-degradable drug carriers, and surgical débridement. Each method has specific drawbacks. We report on the use of a new controlled release system utilizing gentamicin and bioerodible, biocompatible polymers (polyanhydrides) designed for drug delivery applications for the treatment of clinical osteomyelitis. We compared this system's ability to reduce bacterial levels in infected bone with that of conventional non-degradable delivery systems based on polymethylmethacrylate (PMMA) and gentamicin. Polyanhydride copolymers of bis-carboxyphenoxypropane and sebacic acid P loaded with gentamicin sulfate and PMMA/gentamicin matrices were implanted in the long bones of Sprague-Dawley rats infected with a strain of Staphylococcus aureus. After 3 weeks of implantation, the polymeric delivery devices were removed and quantitative cultures were used to determine bacterial levels in bone. The polyanhydride/gentamicin matrices demonstrated significant degradation over the 3 week implantation period. Levels of bacteria, measured in colony forming units, were significantly lower in bone implanted with the polyanhydride/gentamicin release system than in long bones of control animals without an implant (p < 0.01), of animals with a polyanhydride polymer implant alone (p < 0.01), and of animals with a PMMA/gentamicin implant (p = 0.03). Bioerodible polyanhydrides show promise as a new treatment modality for infections in bone.
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