Contribution of Noncanonical Antigens to Virulence and Adaptive Immunity in Human Infection with Enterotoxigenic E. coli.

Enterotoxigenic Escherichia coli (ETEC) contributes significantly to the substantial burden of infectious diarrhea among children living in low- and middle-income countries. In the absence of a vaccine for ETEC, children succumb to acute dehydration as well as nondiarrheal sequelae related to these infections, including malnutrition. The considerable diversity of ETEC genomes has complicated canonical vaccine development approaches defined by a subset of ETEC pathovar-specific antigens known as colonization factors (CFs). To identify additional conserved immunogens unique to this pathovar, we employed an "open-aperture" approach to capture all potential conserved ETEC surface antigens, in which we mined the genomic sequences of 89 ETEC isolates, bioinformatically selected potential surface-exposed pathovar-specific antigens conserved in more than 40% of the genomes (n = 118), and assembled the representative proteins onto microarrays, complemented with known or putative colonization factor subunit molecules (n = 52) and toxin subunits. These arrays were then used to interrogate samples from individuals with acute symptomatic ETEC infections. Surprisingly, in this approach, we found that immune responses were largely constrained to a small number of antigens, including individual colonization factor antigens and EtpA, an extracellular adhesin. In a Bangladeshi cohort of naturally infected children <2 years of age, both EtpA and a second antigen, EatA, elicited significant serologic responses that were associated with protection from symptomatic illness. In addition, children infected with ETEC isolates bearing either etpA or eatA genes were significantly more likely to develop symptomatic disease. These studies support a role for antigens not presently targeted by vaccines (noncanonical) in virulence and the development of adaptive immune responses during ETEC infections. These findings may inform vaccine design efforts to complement existing approaches.

Intentional replantation of adhesively reattached vertically fractured maxillary single-rooted teeth.

AIM: To evaluate the clinical outcomes of intentionally replanted maxillary single-rooted teeth with vertical root fractures (VRFs) after being repaired extraorally using 4-methacryloxyethyl trimellitate anhydride/methacrylate-tri-n-butyl borane (4-META/MMA-TBB) resin cement. METHODOLOGY: Twenty-one root filled maxillary single-rooted teeth with VRFs were evaluated. After atraumatic extraction, fractured fragments were adhesively cemented. The teeth were then replanted and splinted to the neighbouring teeth for 2 weeks. Plaque index (PI), gingival index (GI), probing depth (PD) and clinical attachment level (CAL) were assessed at baseline, 6 and 12 months, and radiographic evaluations were made using PAI scores at baseline and 12 months. Mobility was evaluated using periotest values (PTV) at baseline, 1, 3, 6 and 12 months. Replanted teeth, contralateral teeth (control teeth) and adjacent teeth were analysed statistically using repeated measures one-way anova, unpaired t-tests and Wilcoxon matched-pairs signed-rank tests. RESULTS: Two teeth were extracted in the first month after surgery. PI, GI, CAL and PD scores of the replanted teeth were significantly lower at 6 month (P < 0.0001 for all) and 12 month (P < 0.0001 for all) postoperatively when compared to baseline, but the values were not significantly different from those of the control and adjacent teeth. PTV of the test teeth increased significantly (P < 0.0001) after the intervention and decreased to baseline levels by month 12. PTVs were significantly higher (P < 0.05) at baseline, 1, 3 and 6 months in the test teeth when compared with the control teeth, but were not significantly different at month 12. PAI scores of teeth with VRF were significantly lower (P < 0.05) at 12 months compared with baseline. CONCLUSIONS: Adhesive cementation and intentional replantation were an effective treatment modality for this group of vertically fractured maxillary single-rooted teeth. The clinical periodontal parameters decrease by month 6, and the mobility returned to the physiological limits of natural teeth 12 months after replantation.

Is there an association between obstructive sleep apnea syndrome and periodontal inflammation?

OBJECTIVES: The aim of this study is to assess salivary, serum biomarkers, and subgingival bacteria as putative candidates in the potential association between obstructive sleep apnea syndrome (OSAS) and periodontal disease. MATERIALS AND METHODS: Fifty-two patients were grouped according to the severity of OSAS: 13 participants served as controls, 17 patients had mild-to-moderate OSAS, and 22 severe OSAS. Serum, saliva, and subgingival plaque samples were collected, and clinical periodontal parameters were recorded. Salivary, serum concentrations of interleukin-6 (IL-6), tumour necrosis factor (TNF-α), osteoprotegerin, soluble Receptor activator of nuclear factor kappa B ligand (sRANKL), and apelin were analysed by enzyme-linked immunosorbent assay. Bacterial counts were determined by real-time QPCR on plaque microbial DNA preparations. RESULTS: There was a significant change in the composition of microbes in plaque particularly in severe OSAS samples (p < 0.01). Statistical analyses indicated significantly higher salivary IL-6 levels in both OSAS groups compared to controls (p < 0.05). Salivary apelin levels were significantly higher in the severe OSAS group compared to the control group. Serum levels of these biomarkers and salivary osteoprotegerin, sRANKL levels were similar in the study groups. The incidence and duration of apnea positively correlated with clinical periodontal parameters (p < 0.05). CONCLUSION: OSAS appeared to alter the tested bacteria in plaque, correlate with increasing periodontal disease severity, have additive effect on salivary IL-6. CLINICAL RELEVANCE: OSAS is likely to associate with periodontal disease.

Salivary infectious agents and periodontal disease status.

BACKGROUND AND OBJECTIVES: The potential of salivary microorganisms to diagnose periodontal disease and to guide periodontal treatment is a research topic of current interest. This study aimed to determine whether the salivary counts of periodontopathic microbes correlated with the periodontal pocket counts of the same infectious agents, and whether the salivary counts of the test infectious agents could distinguish among individuals with periodontal health and various types of periodontal disease. MATERIAL AND METHODS: The study included 150 systemically healthy adults, of whom 37 were periodontally healthy, 31 had gingivitis, 46 had chronic periodontitis and 36 had aggressive periodontitis. Each study subject contributed microbial samples from the two deepest periodontal pockets of the dentition and from whole saliva. Aggregatibacter actinomycetemcomitans, Campylobacter rectus, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia and Epstein-Barr virus were identified using the TaqMan real-time PCR methodology. Statistical analysis was performed using the Mann-Whitney U-test and the receiver operating characteristic statistics. RESULTS: C. rectus, F. nucleatum, P. gingivalis, P. intermedia and T. forsythia occurred with significantly higher copy-counts in salivary samples from patients with gingivitis, chronic periodontitis and aggressive periodontitis than from periodontally healthy individuals. A. actinomycetemcomitans only showed higher salivary copy-counts in subjects with aggressive periodontitis compared with subjects with healthy periodontium, and the salivary copy-counts of Epstein-Barr virus did not reveal any significant difference among the four subject groups studied. The diagnostic sensitivity for periodontitis was 89.19 for P. gingivalis and for T. forsythia and 86.49 for P. intermedia, with specificities ranging from 83.78 to 94.59. The optimal copy-counts per mL saliva for identifying periodontitis were 40,000 for P. gingivalis, 700,000 for T. forsythia and 910,000 for P. intermedia. CONCLUSION: Salivary copy-counts of P. gingivalis, T. forsythia and P. intermedia appear to have the potential to identify the presence of periodontitis, whereas the salivary level of the other test infectious agents may possess little or no diagnostic utility. Longitudinal studies are warranted to determine the ability of salivary copy-counts of major periodontopathic bacteria to predict future periodontal breakdown.

Is belching increasing after bariatric bypass surgery in the long term period?

BACKGROUND AND AIMS: Gastric bypass surgery effectively treats obesity; however, its association with belching, which occurs in other bariatric surgeries, remains unclear. Hence, we aimed to evaluate belching occurrence after gastric bypass surgery. METHODS: We enrolled 12 healthy volunteers and 17 patients (12 and 5 underwent Roux-en-Y gastric bypass and mini-gastric bypass surgeries 24 (18-54) months prior, respectively). Gastrointestinal symptoms were assessed. Gastroscopy was performed, followed by the 24-hour pH-impedance analysis. RESULTS: Age and sex were not statistically different between the two groups (P > 0.05). Patients had a significantly higher mean DeMeester score than the healthy controls (9.11 ± 19.40 vs. 6.04 ± 5.60, P = 0.048), but the pathologic acid reflux (DeMeester score > 14) rate was similar in both groups (11.8% vs. 8.3%). Regarding the impedance, symptom-association probability was positive in 11.8% of patients. The patients also had higher alkaline reflux rates (6% vs. 0%); additionally, 50% of them experienced belching based on the questionnaire, and 25% had esophagitis based on gastroscopy. Furthermore, patients had a significantly higher number of gas reflux (123.24 ± 80 vs. 37.2 ± 21.5, P = 0.001) and supragastric/ gastric belches (182 ± 64/228 ± 66.69 vs. 25.08 ± 15.20/12.17 ± 17.65, P = 0.001). Supragastric belching was more frequent than gastric belching in the controls, whereas gastric belching was more frequent in the patients. CONCLUSION: Belching increases after gastric bypass surgery in a long-term period. Gastric belching was more frequent than supragastric belching in these patients.

Extra-short implants in the prosthetic rehabilitation of the posterior maxilla.

AIM: To compare clinical outcomes of 'extra-short' and regular bone level implants in the posterior maxilla for 12 months after loading. MATERIALS AND METHODS: Twenty-three systemically healthy, non-smoking patients received 30 extra-short, 24 regular bone level implants. Acrylic stents were fabricated for each patient for correct implant positioning. Implant lengths were 4-6 mm in the test, 8/10 mm in the control group. Radiographic evaluation was performed at baseline, 6, and 12 months after loading. Crestal bone level (CBL), CBL change (CBLC), true crown length (TCL), implant/crown ratio (ICR) and residual bone height (RBH) below maxillary sinus floor were calculated digitally. Data were tested statistically. RESULTS: Residual bone height was significantly lower, and TCL and ICR were higher in the test than the control group (P < 0.0001). CBL measurements at baseline were 0.19 ± 0.18 mm and 0.31 ± 0.37 mm and at 12 months, 0.24 ± 0.24 mm and 0.41 ± 0.31 mm, respectively in the test and control groups. CBL values at 12 months were significantly lower in the test than the control group (P < 0.05). CBLCs were similar at all times (P > 0.05). No correlation was found between the CBLC and implant/prosthetic parameters. CONCLUSION: Extra-short and regular implants might provide similar clinical outcomes in prosthetic rehabilitation of atrophic maxilla, during 12 months follow-up.

Do MMP-1 levels of gingival fibroblasts have a role in the gingival overgrowth of cyclosporine-treated patients?

The aim of this study was to compare the matrix metalloproteinase-1 (MMP-1) levels in gingival fibroblast cultures derived from two groups of renal transplant patients receiving cyclosporine (CsA) who exhibit gingival overgrowth and who have healthy periodontium. Gingival fibroblasts obtained from four patients with CsA-induced gingival overgrowth (CsA-GO) and four patients who receive CsA but have healthy periodontium were incubated with increasing concentrations of CsA and cultured for 72 hours. Expression levels of MMP-1 in all the groups were measured four times at 0, 24, 48, and 72 hours by the Rapid Collagenase Assay Kit. No significant difference was seen at baseline. As the CsA concentration and the duration in the cell media increased, the CsA-GO showed that fibroblasts displayed significantly suppressed MMP-1 levels with respect to the baseline, at which fibroblasts from CsA patients with healthy periodontium exhibited the same result as at the highest CsA concentration. Results of this study indicated that CsA therapy did not have a significant effect on MMP-1 levels. Since the overall pathogenesis of drug-induced gingival hyperplasia has been accepted as multifactorial, down-regulation of MMP-1 expression may play a minor role.

Evaluation of telomerase activity in gingival fibroblasts of cyclosporine-treated patients.

Gingival overgrowth (GO) is a common side effect following administration of cyclosporin A (CsA). Various case reports have shown that squamous cell carcinomas could arise in GO induced by CsA and phenytoin. It is also known that human telomerase activated in about 90% of cancers is mainly composed of hTR, hTERT, and TPI. The aim of this study was to investigate the potential role of telomerase activity in the pathogenesis of CsA-induced GO. Included in the study were 9 patients on CsA: 4 with and 5 without GO. Gingival tissues were obtained during gingivectomy or flap procedures; gingival fibroblasts were cultured in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10,000 U/mL penicillin, 10 mg/mL streptomycin, 2 mmol/L l-glutamine, and 10% heat-inactivated fetal bovine serum at 37 degrees C under a humidified 95% air virgule 5% CO(2) atmosphere. Quantitative detection of hTERT mRNA was performed with the commercially available LightCycler Telo TAGGG hTERT Quantification Kit using real-time online PCR. The hTERT mRNA expression was positive in one patient, while hTERT mRNA expression was negative in the others. Because results indicated that there may be a relationship between CsA-induced GO and positive telomerase activity, detailed studies should be performed to confirm the present findings.

Differentiation of Chronic and Aggressive Periodontitis by FTIR Spectroscopy.

Without longitudinal clinical data, it is difficult to differentiate some cases of chronic periodontitis (CP) and aggressive periodontitis (AgP). Furthermore, both forms of disease are exacerbated by tobacco use. Therefore, this cross-sectional study was planned, primarily, to determine the ability of Fourier-transform infrared (FTIR) spectroscopy to distinguish CP and AgP patients by analysis of human saliva samples and, secondarily, to assess the potential confounding influence of smoking on discriminating disease-specific spectral signatures. FTIR spectra were collected from patients with a clinical diagnosis of CP (n = 18; 7 smokers) or AgP (n = 23; 9 smokers). Self-reported smoking status, which may be unreliable, was confirmed by salivary cotinine analysis. Spectral band area analysis and hierarchical cluster analyses were performed to clarify if the 2 periodontitis groups as well as smoker and nonsmoker patients could be differentiated from each other. Significant variations in lipid, amino acid, lactic acid, and nucleic acid content were found between nonsmoker CP and AgP groups. Although significantly lower lipid, phospholipid, protein, amino acid, lactic acid, and nucleic acid content was noted in the smoker AgP group compared with the nonsmoker AgP group, in the CP group, phospholipid, protein, amino acid, and lactic acid content was significantly lower for smokers compared with the nonsmokers. Based on these variations, nonsmoker CP and AgP patients were discriminated from each other with high sensitivity and specificity. Successful differentiation was also obtained for the smoker CP and AgP groups. Thiocyanate levels successfully differentiated smokers from nonsmokers, irrespective of periodontal status, with 100% accuracy. Differentiation of AgP and CP forms, concomitant with determination of smoking status, may allow the dental health professional to tailor treatment accordingly.