Antimicrobial activity of amixicile against Treponema denticola and other oral spirochetes associated with periodontal disease.

BACKGROUND: Periodontal disease is a polymicrobial infection characterized by inflammation of the gingiva, alveolar bone resorption and tooth loss. As periodontal disease progresses, oral treponemes (spirochetes) become dominant bacteria in periodontal pockets. Oral treponemes are anaerobes and all encode the enzyme pyruvate-ferredoxin oxidoreductase (PFOR) which catalyzes the oxidative decarboxylation of pyruvate to acetyl-CoA. Here we assess the susceptibility of oral treponemes to amixicile (AMIX), a novel inhibitor of PFOR. METHODS: The minimum inhibitory concentration (MIC) of AMIX against several oral treponeme species was determined. The impact of AMIX on processes relevant to virulence including motility, H2 S production, and complement evasion were determined. RESULTS: The growth of all oral treponeme species tested was inhibited by AMIX with MIC concentrations (MIC) ranging from 0.5-1.5 µg/mL. AMIX significantly reduced motility, caused a dose-dependent decrease in hydrogen sulfide production and increased sensitivity to killing by human complement (i.e., serum sensitivity). CONCLUSIONS: AMIX is effective in vitro in inhibiting growth and other processes central to virulence. AMIX could serve could serve as a new selective therapeutic tool for the treatment of periodontal disease.

The Treponema denticola FhbB Protein Is a Dominant Early Antigen That Elicits FhbB Variant-Specific Antibodies That Block Factor H Binding and Cleavage by Dentilisin.

The Treponema denticola FhbB protein contributes to immune evasion by binding factor H (FH). Cleavage of FH by the T. denticola protease, dentilisin, may contribute to the local immune dysregulation that is characteristic of periodontal disease (PD). Although three FhbB phyletic types have been defined (FhbB1, FhbB2, and FhbB3), the in vivo expression patterns and antigenic heterogeneity of FhbB have not been assessed. Here, we demonstrate that FhbB is a dominant early antigen that elicits FhbB type-specific antibody (Ab) responses. Using the murine skin abscess model, we demonstrate that the presence or absence of FhbB or dentilisin significantly influences Ab responses to infection and skin abscess formation. Competitive binding analyses revealed that α-FhbB Ab can compete with FH for binding to T. denticola and block dentilisin-mediated FH cleavage. Lastly, we demonstrate that dentilisin cleavage sites reside within critical functional domains of FH, including the complement regulatory domain formed by CCPs 1 to 4. Analysis of the FH cleavage products revealed that they lack cofactor activity. The data presented here provide insight into the in vivo significance of dentilisin, FhbB and its antigenic diversity, and the potential impact of FH cleavage on the regulation of complement activation.

Synovial chondromatosis of the temporomandibular joint: a case report and literature review.

Synovial chondromatosis (SC) is a pathologic condition in which mesenchymal tissue rests in a given synovial membrane undergo a metaplastic process, ultimately producing and secreting cartilaginous bodies into the joint space. It is more commonly discussed in the orthopedic literature, since the axial skeleton is the most frequently affected. Although rare, it does occur within the temporomandibular joint (TMJ), with approximately 100 cases previously being described. Within the TMJ, its presentation can be variable, though most cases will show it to be unilateral with fixed and/or loose cartilaginous bodies confined to the superior joint space. Clinically, patients may present with symptoms similar to that of an internal derangement disorder, including pain, clicking, tenderness, functional limitations, and swelling. A thorough history and physical examination, along with proper radiographic examination, are paramount in properly diagnosing SC. Treatment options consist of arthroscopy, arthrotomy with synovectomy, excision of cartilaginous bodies, and possible discectomy. In the current paper, the authors describe the presentation, diagnosis, and surgical management of a SC case involving the right TMJ in a 31-year-old Caucasian female.

The measurement of normative American Shoulder and Elbow Surgeons scores.

We determined baseline scores on the American Shoulder and Elbow Surgeons (ASES) questionnaire in individuals who had no known shoulder condition and evaluated related factors that could influence the score. A modified version of the questionnaire was completed by 343 patients from an outpatient orthopaedic center being seen for conditions unrelated to the shoulder. A separate group completed the questionnaire at two different times to assess its reliability. The mean ASES score was 92.2 +/- 14.5 points. The instrument was found to be very reliable (intraclass correlation coefficient = 0.96). Only the variables of shoulder status and sports participation entered the regression model to explain the variance in scores. Subjects aged 60 years or older exhibited decreased ability to lift above shoulder level and reach behind the back when compared with younger cohorts. Previous investigators have made the assumption that a normal preinjury ASES score is 100 points. This study raises questions about this assumption. This information can serve as a basis to compare normative scores with those of patients with active shoulder disease.