Defining Species-Specific Immunodominant B Cell Epitopes for Molecular Serology of Chlamydia Species

Urgently needed species-specific enzyme-linked immunosorbent assays (ELISAs) for the detection of antibodies against Chlamydia spp. have been elusive due to high cross-reactivity of chlamydial antigens. To identify Chlamydia species-specific B cell epitopes for such assays, we ranked the potential epitopes of immunodominant chlamydial proteins that are polymorphic among all Chlamydia species. High-scoring peptides were synthesized with N-terminal biotin, followed by a serine-glycine-serine-glycine spacer, immobilized onto streptavidin-coated microtiter plates, and tested with mono-specific mouse hyperimmune sera against each Chlamydia species in chemiluminescent ELISAs. For each of nine Chlamydia species, three to nine dominant polymorphic B cell epitope regions were identified on OmpA, CT618, PmpD, IncA, CT529, CT442, IncG, Omp2, TarP, and IncE proteins. Peptides corresponding to 16- to 40-amino-acid species-specific sequences of these epitopes reacted highly and with absolute specificity with homologous, but not heterologous, Chlamydia monospecies-specific sera. Host-independent reactivity of such epitopes was confirmed by testing of six C. pecorum-specific peptides from five proteins with C. pecorum-reactive sera from cattle, the natural host of C. pecorum. The probability of cross-reactivity of peptide antigens from closely related chlamydial species or strains correlated with percent sequence identity and declined to zero at <50% sequence identity. Thus, phylograms of B cell epitope regions predict the specificity of peptide antigens for rational use in the genus-, species-, or serovar-specific molecular serology of Chlamydia spp. We anticipate that these peptide antigens will improve chlamydial serology by providing easily accessible assays to nonspecialist laboratories. Our approach also lends itself to the identification of relevant epitopes of other microbial pathogens.     

Polymerization behavior and thermal characteristics of two new composites at five temperatures: refrigeration to preheating

PURPOSE

Heat of composite polymerization (HP) indicates setting efficacy and temperature increase of composite in clinical procedures. The purpose of this in vitro experimental study was to evaluate the effects of 5 temperatures on HP of two new composites.

MATERIALS AND METHODS

From each material (Core Max II [CM] and King Dental [KD]), 5 groups of 5 specimens each were prepared and their total HPs (J/gr) were measured and recorded, at one of the constant temperatures 0℃, 15℃, 23℃, 37℃ and 60℃ (2 × 5 × 5 specimens) using a differential scanning calorimetry (DSC) analyzer. The data were analyzed using a two-way ANOVA, a Tukey''s test, an independent-samples t-test, and a linear regression analysis (α=0.05).

RESULTS

No polymerization reactions occurred at 0℃; then this temperature was excluded from statistical analyses. The mean HP of the remaining 20 KD specimens was 20.5 ± 14.9 J/gr, while it was 40.7 ± 12.9 J/gr for CM. The independent-samples t-test showed that there were significant differences between the HP of the two materials at the temperatures 15℃ (P=.0001), 23℃ (P=.0163), 37℃ (P=.0039), and 60℃ (P=.0106). Linear regression analysis showed statistically significant correlations between environment temperatures and HP of CM (R²=0.777).

CONCLUSION

Using CM is advantageous over conventional composite because of its better polymerization capacity. However due to its high HP, further studies should assess its temperature increase in vivo. Preheating KD is recommended. Refrigerating composites can negatively affect their polymerization potential.     

Association between race and oncologic outcome following radical prostatectomy for clinically organ-confined prostate cancer: a long-term follow-up study

Purpose

Few studies have evaluated prostate cancer oncologic outcomes in different ethnic groups following radical prostatectomy for clinically organ-confined disease. Existing studies lack long-term outcome data. We conducted this study to assess the impact of racial differences on risk profile and oncologic outcomes in a large cohort of patients with prostate cancer who underwent radical prostatectomy.

Methods

Using our institutional review board-approved prostate cancer database, we retrospectively reviewed the records of 3437 patients who underwent radical prostatectomy with curative intent in our institution between 1987 and 2009. Based on ethnicity, patients were divided into Asian Americans (n?=?133), African Americans (n?=?155) and Caucasians (n?=?3149). Baseline characteristics and oncologic outcomes including biochemical recurrence free, clinical recurrence free and overall survival were compared between the study groups.

Results

A total of 3437 patients with a mean age of 63?±?9.8 years and median follow-up period of 8.7 (range 0.1–24.1) years were included in the analysis. Pathologic stage and the frequency of poorly differentiated cancer were higher in Asian Americans; however, margin status did not differ significantly. Moreover, oncologic outcomes were comparable between different ethnic groups. In multivariate analysis, both pathologic stage and grade were independent predictors of oncologic outcomes, but race was not.

Conclusions

In this large, ethnically diverse long-term follow-up study, we noted that Asian Americans compared to African Americans and Caucasians are more likely to have high risk prostate cancer; however, race was not an independent predictor of oncologic outcome following radical prostatectomy with curative intent.

     

呼吸衰竭的营养支持

许多重症疾病都合并有呼吸功能不全,而呼吸衰竭患者常伴有营养不良。营养不良可影响呼吸肌的功能,引起肺组织结构改变及降低呼吸道的抗感染防御机能,故营养支持对呼吸衰竭的病程发展及转归影响很大。过多地给予碳水化合物可使氧的消耗及二氧化碳的生成增加。合理地摄取糖、脂肪和蛋白质是治疗呼吸衰竭所必需的。