Characterization of treponemes isolated from human and non-human primate periodontal pockets

Treponemes were isolated from ligature induced periodontal pockets of non-human primates, and from humans with periodontitis. Approximately 39% of the microscopic count were spirochetes from humans, while 65% of the microscopic microbiota was accounted for by spirochetes from non-human primates. Metabolically, the human treponemal isolates grew on trypticase-yeast extract based media while the non-human primate isolates grew only on pectin, glucuronic or galacturonic acids. The end-products of glucose fermentation by the human treponemes were acetate and propionate, while acetate was produced by the non-human primate treponemes from pectin. All of the human isolates were indole positive, hemolyzed blood, required serum for growth, but did not require thiamine pyrophosphate (TPP). The non-human primate treponemes were indole negative, were inhibited in their growth by blood, grew in the absence of serum, and required TPP for growth. PAGE analysis of whole cell proteins revealed three categories of treponemal isolates: (i) human isolates similar to Treponema denticola ; (ii) human isolates of small size; and (iii) non-human primate isolates similar to the pectinolytic treponemes. Serologically, the human treponemal isolates were similar to T. denticola , while the non-human primate isolates were similar to the pectinolytic treponemes. Four human, 4 non-human primate, and 4 reference treponemes exhibited a Mol% G + C of their DNA of 40.0-43.1. The metabolic differences between the human and non-human primate treponemal isolates may be a reflection of ecological differences in the periodontium of the pathological entities which exist in human and non-human primates.     

Microbiologic and immunologic characteristics of periodontal disease in Hispanic americans with type 2 diabetes

BACKGROUND: The microbiology of periodontitis in type 1 diabetes has been reported, but less is known about type 2 diabetes. Moreover, these data have not linked microbial colonization, host response, and clinical presentation in type 1 or type 2 diabetes. The objectives of this study were to relate periodontal status, periodontal microorganisms, and host-response characteristics in Hispanic Americans with type 2 diabetes. METHODS: Plaque and serum samples were obtained from 63 Hispanic American subjects with and without type 2 diabetes. The microbiology of subgingival plaque samples was evaluated using DNA checkerboard hybridization, and serum antibody to a battery of oral microorganisms was determined using an enzyme-linked immunosorbent assay. RESULTS: In general, similar pathogens were present in periodontitis sites from subjects with and without type 2 diabetes, although the periodontitis sites in diabetes showed a higher frequency of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans), and Campylobacter spp. Serum antibody to Campylobacter rectus was elevated in type 2 diabetes, whereas antibody to P. gingivalis and C. rectus were elevated in subjects with periodontitis, irrespective of diabetes status. Stratification of the population based upon antibody to P. gingivalis or C. rectus suggested a linkage between elevated antibody to P. gingivalis, increased frequency of diabetes, and significantly worse periodontitis. CONCLUSION: The increased severity of periodontal disease with type 2 diabetes may reflect an alteration of the pathogenic potential of periodontal bacteria and/or a modification of the characteristics of the host's inflammatory response that may contribute to a breakdown in the homeostasis of the periodontium.     

Designing Clinical Trials for Dystonia

With advances in the understanding of the pathophysiology of dystonia, novel therapeutics are being developed. Such therapies will require clinical investigation ranging from exploratory studies to examine safety, tolerability, dosage selection, and preliminary efficacy to confirmatory studies to evaluate efficacy definitively. As dystonia is a rare and complex disorder with clinical and etiological heterogeneity, clinical trials will require careful consideration of the trial design, including enrollment criteria, concomitant medication use, and outcome measures. Given the complexities of designing and implementing efficient clinical trials, it is important for clinicians and statisticians to collaborate closely throughout the clinical development process and that each has a basic understanding of both the clinical and statistical issues that must be addressed. To facilitate designing appropriate clinical trials in this field, we review important general clinical trial and regulatory principles, and discuss the critical components of trials with an emphasis on considerations specific to dystonia. Additionally, we discuss designs used in early exploratory, late exploratory, and confirmatory phases, including adaptive designs.     

Transcutaneous PO2 poorly estimates arterial PO2 in adults during anesthesia

We compared values of P_aO₂ and transcutaneous PO₂ in 21 adult patients during anesthesia. In 282 simultaneous determinations during anesthetic periods of 3–10 h, transcutaneous PO₂ was a poor predictor of absolute P_aO₂ and changes in P_aO₂. Trancutaneous PO₂ monitoring in adults during anesthesia is of unproven value.     

Arterial reconstructions for chronic lower extremity ischemia in preadolescent and adolescent children

Objective

Chronic lower extremity ischemia in pediatric patients is uncommon. The intent of this study was to better define the arterial reconstructive options and their long-term durability in preadolescent and adolescent children having clinically relevant arterial occlusions affecting the lower extremity.