Identification of subcomplexes and protein-protein interactions in the DNA transporter of Thermus thermophilus HB27.

The natural transformation system of the thermophilic bacterium Thermus thermophilus comprises at least 16 competence proteins. Recently we found that the outer membrane (OM) competence protein PilW interacts with the secretin channel, which guides type IV pili (T4P) and potential DNA transporter pseudopili through the OM. Here we have used biochemical techniques to study the interactions of cytoplasmic, inner membrane (IM) and OM components of the DNA transporter in T. thermophilus. We report that PilW is part of a heteropolymeric complex comprising of the cytoplasmic PilM protein, IM proteins PilN, PilO, PilC and the secretin PilQ. Co-purification studies revealed that PilO directly interacts with PilW. In vitro affinity co-purification studies using His-tagged PilC led to the detection of PilC-, PilW-, PilN- and PilO-containing complexes. PilO was identified as direct interaction partner of the polytopic IM protein PilC. PilC was also found to directly interact with the cytoplasmic T4P disassembly ATPase PilT1 thereby triggering PilT1 ATPase activity. This, together with the detection of heteropolymeric PilC complexes which contain PilT1 and the pilins PilA2, PilA4 and PilA5 is in line with the hypothesis that PilC connects the depolymerization ATPase to the base of the pili possibly allowing energy transduction for disassembly of the pilins.

The link between total antioxidant status, total oxidant status, arylesterase activity, and subgingival microbiota in psoriasis patients.

BACKGROUND: Studies focusing on the relationship between periodontitis and systemic diseases have suggested a possible association between these two chronic and inflammatory disorders. We aimed to comparatively investigate the salivary oxidative status, biomarker levels, clinical findings, and the microbial load on subgingival biofilm samples in psoriasis patients and controls. METHODS: Forty participants were allocated into four groups as follows: (1) systemically and periodontally healthy (C group); (2) systemically healthy with periodontitis (P group); (3) psoriasis (Ps) and periodontally healthy (Ps-C group); and (4) Ps with periodontitis (Ps-P group). Subgingival biofilm samples were obtained to detect the periodontopathogenic agents by Real-time PCR (qPCR). The total antioxidant status (TAS) (mmol/l), total oxidant status (TOS) (µmol/l), and arylesterase (ARE) activity (U/L) were analyzed using saliva samples. RESULTS: The level of TOS and oxidative stress index (OSI) were significantly higher in patients with Ps-P and P compared to controls (P = 0.001, and P ˂ 0.001, respectively). ARE levels were higher in controls compared to Ps and P (P ˂ 0.001). The prevalences of bacteria detected in subgingival biofilm samples were similar between all groups (P > 0.05). CONCLUSIONS: This study reported that psoriasis may amplify TOS and OSI, and the co-existence of psoriasis and periodontitis may aggravate oxidative stress.

Evaluation of Bacterial Colonization and Clinical Properties of Different Suture Materials in Dentoalveoler Surgery.

PURPOSE: This study aimed to compare the effects of 10 different suture materials commonly used in dentoalveolar surgery on wound healing, their postoperative microbial colonization, and related clinical parameters. METHODS: A total of 172 suture samples from patients who had undergone extraction of impacted third molars were included in the study. The suture materials studied were poly-glycolide-colactide, fast absorbable poly-glycolide-colactide, poly-glycolic acid-cocaprolactone, polydioxanone, silk, polypropylene, polyvinylidene difluoride, polyamide, polyester, and polytetrafluoroethylene (PTFE). The microbial colonization in all sutures and clinical parameters were evaluated after 1 week. RESULTS: Multifilament sutures had higher bacterial colonization compared with monofilament sutures (P < .001). No dental plaque accumulation was observed in any samples of polypropylene sutures. Polydioxanone, PTFE, and poly-glycolic acid-cocaprolactone sutures exhibited less postoperative slack compared with all other sutures after 1 week. Patients with silk, polyvinylidene difluoride, and PTFE sutures had less suture-related discomfort. According to the Landry index score, monofilament sutures demonstrated superior wound healing to multifilament sutures (P = .019). In addition, nonabsorbable sutures showed significantly better wound epithelization than absorbable sutures (P ˂ .001). CONCLUSIONS: Bacterial colonization and tissue reactions due to the surface properties of the suture affected the wound healing after dentoalveolar surgery. Multifilament sutures should not be applied for prolonged periods because of their tendency for microbial colonization. The tissue reaction to the absorbable suture materials may adversely affect wound healing.

The effects of Biofreeze and superficial heat on masticatory myofascial pain syndrome.

PURPOSE: This study aims to assess the influence of superficial heat and Biofreeze on pain, mouth opening (mm), and quality of life in patients with masticatory myofascial pain syndrome (MPS). MATERIALS AND METHODS: 52 patients with MPS were included in the study. They were randomly divided into two groups. Patients in the Biofreeze group (n = 26) applied 3.5% menthol gel to the masseter and temporal muscles twice a day for seven days, while the other group applied superficial heat. Baseline, 7th, and 21st days of VAS, mouth opening (mm), and Oral Health Impact Profile-14 (OHIP-14) scores of the patients were evaluated statistically. RESULTS: The mouth opening increased by 4.27 ± 3.80 mm in the Biofreeze group and 2.58 ± 2.16 mm in the superficial heat group. In each group, a significant decrease in VAS and OHIP-14 scores was observed on the 7th day compared to the baseline values (p<0.001). There was no statistically significant difference between the two applications on myofascial pain, mouth opening (mm), and OHIP-14 total score variables. The favorable effects of both applications on these parameters were limited to the duration of use. CONCLUSION: Biofreeze and superficial heat in MPS were found to increase the quality of life, but the limited effectiveness of these applications underlines the importance of the underlying factors.

Natural transformation in Gram-negative bacteria thriving in extreme environments: from genes and genomes to proteins, structures and regulation.

Extremophilic prokaryotes live under harsh environmental conditions which require far-reaching cellular adaptations. The acquisition of novel genetic information via natural transformation plays an important role in bacterial adaptation. This mode of DNA transfer permits the transfer of genetic information between microorganisms of distant evolutionary lineages and even between members of different domains. This phenomenon, known as horizontal gene transfer (HGT), significantly contributes to genome plasticity over evolutionary history and is a driving force for the spread of fitness-enhancing functions including virulence genes and antibiotic resistances. In particular, HGT has played an important role for adaptation of bacteria to extreme environments. Here, we present a survey of the natural transformation systems in bacteria that live under extreme conditions: the thermophile Thermus thermophilus and two desiccation-resistant members of the genus Acinetobacter such as Acinetobacter baylyi and Acinetobacter baumannii. The latter is an opportunistic pathogen and has become a world-wide threat in health-care institutions. We highlight conserved and unique features of the DNA transporter in Thermus and Acinetobacter and present tentative models of both systems. The structure and function of both DNA transporter are described and the mechanism of DNA uptake is discussed.

Functional dissection of structural regions of the Thermus thermophilus competence protein PilW: Implication in secretin complex stability, natural transformation and pilus functions.

Uptake of DNA from the environment into the bacterial cytoplasm is mediated by a macromolecular transport machinery that is similar in structure and function to type IV pili (T4P) and, indeed, DNA translocator and T4P share common components. One is the secretin PilQ which is assembled into homopolymeric complexes forming highly dynamic outer membrane (OM) channels mediating pilus extrusion and DNA uptake. How PilQ interacts with the motor is still enigmatic. Here, we have used biochemical and genetic techniques to study the interaction of PilQ with PilW, a unique protein which is essential for natural transformation and T4P extrusion of T. thermophilus. PilQ and PilW form high molecular mass complexes in the OM of T. thermophilus. When pilW was deleted, PilQ complexes were no longer observed but only PilQ monomers, accompanied by a loss of DNA uptake as well as a loss of T4P and twitching motility. Piliation of a ΔpilT2/ΔpilW double mutant suggests that PilW is important for stable assembly of PilQ complexes. To analyze the role of different regions of PilW, partial deletions (pilW∆2-40, pilW∆50-150, pilW∆163-216 and pilW∆216-292) were generated and the effect on DNA uptake, PilQ complex formation and T4P functions such as twitching motility, biofilm formation and cell-cell interaction was studied. These studies revealed that a central disordered region in PilW is required for pilus dynamics. We propose that PilW is part of a protein network that connects the transport ATPase to drive different functions of the DNA translocator and T4P.

Dental and temporomandibular joint alterations in rheumatoid arthritis patients and their association with salivary oxidative stress

Background/aim: Rheumatoid arthritis (RA) is the most extensive inflammatory arthritis causing permanent deformities in the joint. Increasing evidence suggests that oxidative stress is a substantial factor in the pathogenesis of RA. This study aimed to examine the salivary oxidant-antioxidant status of RA and control groups and to compare these biomarkers by correlating them with disease activity, acute phase reactants, and clinical findings. Materials and methods: Age and sex-matched 60 participants including 30 patients with RA and 30 control (50 females, 10 males; mean age: 42.62 ± 10.89 years) were evaluated. RA disease activity and severity were evaluated by the disease activity score 28-C reactive protein (DAS 28-CRP). Rheumatoid factor (RF) positivity, anticitrullinated protein antibodies (ACPA) positivity, erythrocyte sedimentation rate (ESR), CRP, tender and swollen joint counts, and medical treatment regimens of the patients (glucocorticoids, conventional or biologic disease-modifying antirheumatic drugs) were recorded. In the radiographic examination, dental findings, and bone alterations of the temporomandibular joint (TMJ) were recorded and compared for both groups. Saliva samples were obtained for analysis of total antioxidant status (TAS), total oxidant status (TOS), arylesterase (ARE), and oxidative stress index (OSI) levels. The data analysis was conducted by independent sample t-test and chi-square test. Results: Condylar erosion was the most common radiographic change in TMJ of RA patients. Osteophyte formation was a prominent finding in the control group. Lower TAS and higher OSI levels were found in RA patients compared with controls (p = 0.013; p = 0.029, respectively). The effect of DAS 28-CRP score on the levels of oxidative stress biomarkers in RA patients was not significant. Conclusion: Oxidative stress causes tissue damage in response to excessive mechanical loading, which in turn promotes TMD. However, disease activity has not a prominent impact on the salivary oxidative stress status of RA patients.

Correlation of molecular biomarker concentrations between synovial fluid and saliva of the patients with temporomandibular disorders.

OBJECTIVES: The synovial membrane and fluid are involved in the pathogenesis of temporomandibular joint (TMJ) disorders. This study aims to assess the relationship between matrix metalloproteinase-2 (MMP-2), chemerin and prostaglandin (PGE2) levels in the synovial fluid (SF) and saliva of patients with TMJ disorder regarding their role in inflammation and the value of being a candidate for predictive biomarkers in the disease. Also, it is aimed to find out whether chemerin's main function triggers the formation inflammatory cytokine markers in the associated area. MATERIALS AND METHODS: Thirty-two samples of SF and saliva were obtained from patients with disc displacement without reduction with limited opening (DDWORwLO). Mann-Whitney-U test was used for the comparisons of the biomarker levels in SF and saliva. The correlation between chemerin and BMI (Body Mass Index) is analyzed by non-parametric Spearman's rho correlation coefficient. RESULTS: For all of the three biomarkers, statistically significant differences were found between SF and saliva. An unexpectedly high level expression of chemerin was observed in SF. A statistically significant, positive correlation was observed between PGE2 -MMP-2, and chemerin-PGE2 in saliva, chemerin and MMP-2 in SF, respectively (p = 0.031, r = 0.382 / p = 0.039, r = 0.366 / p = 0.032, r = 0.379). A positive correlation was determined between saliva and SF levels of PGE2 (p = 0.016, r = 0.421). CONCLUSIONS: Chemerin, MMP-2, and PGE2 can play a role as an inflammatory factor for the development of TMJ disorder. CLINICAL RELEVANCE: The search for molecular markers in TMJ and the inhibition of the associated molecular signaling mechanism is important to reduce joint inflammation and cartilage degradation.

Evaluation of the Relationship of Dimensions of Maxillary Sinus Drainage System with Anatomical Variations and Sinusopathy: Cone-Beam Computed Tomography Findings.

OBJECTIVE: The aim of this study was to evaluate the correlation between the length of the infundibulum and ostium height with the anatomic variations of osteomeatal complex (OMC) and sinus pathology using cone-beam computed tomography (CBCT). METHODS: CBCT images of 204 patients (408 maxillary sinuses) were evaluated retrospectively. The height of the ostium and the length of the infundibulum were measured. The presence of maxillary sinus pathology, nasal septal deviation, Haller cells, concha bullosa, and sinus septa were analyzed. The correlation between the size of the maxillary sinus drainage system and anatomic variations was compared using the t test, Fisher's exact test, and χ2 test. The effect of tooth loss on the length of the infundibulum and ostium height was also analyzed using ANOVA. RESULTS: The height of the ostium and the maximal septal deviation angle were found to be significantly greater in males (p < 0.05). As ostium height increased, the presence of maxillary sinus septa increased (p < 0.05). No statistically significant association was detected between other variations and the length of infundibulum or ostium height. The relationship between tooth loss and both the length of the infundibulum and ostium height were found to be insignificant (p > 0.05). CONCLUSIONS: Radiographic examination, especially on CBCT images, is important for an evaluation of maxillary sinuses. here, we demonstrated a significant relationship between ostium height and the presence of maxillary sinus septa. However, it was found that nasal septal deviation, concha bullosa, Haller cells, and other sinusopathies did not have a major effect on the size of the maxillary sinus drainage system.