The TRIM69-MST2 signaling axis regulates centrosome dynamics and chromosome segregation.

Stringent control of centrosome duplication and separation is important for preventing chromosome instability. Structural and numerical alterations in centrosomes are hallmarks of neoplastic cells and contribute to tumorigenesis. We show that a Centrosome Amplification 20 (CA20) gene signature is associated with high expression of the Tripartite Motif (TRIM) family member E3 ubiquitin ligase, TRIM69. TRIM69-ablation in cancer cells leads to centrosome scattering and chromosome segregation defects. We identify Serine/threonine-protein kinase 3 (MST2) as a new direct binding partner of TRIM69. TRIM69 redistributes MST2 to the perinuclear cytoskeleton, promotes its association with Polo-like kinase 1 (PLK1) and stimulates MST2 phosphorylation at S15 (a known PLK1 phosphorylation site that is critical for centrosome disjunction). TRIM69 also promotes microtubule bundling and centrosome segregation that requires PRC1 and DYNEIN. Taken together, we identify TRIM69 as a new proximal regulator of distinct signaling pathways that regulate centrosome dynamics and promote bipolar mitosis.

Recurrent black stains and periodontal disease.

OBJECTIVES: The objective of this study was to identify the anaerobic pigment-forming bacteria present in black stain and correlate its occurrence with dental caries incidence and periodontal destruction. MATERIALS AND METHODS: A total of 50 healthy subjects with the chief complaint of recurrent black stains were selected based on the inclusion and exclusion criteria. decayed/missing/filled surfaces score, community periodontal index, Gingival Crevicular Fluid (GCF), black stain score, and microbial analysis were done. RESULTS: The data presented indicate that black stain has a constant microflora, dominated by various gram-negative rods, gram-positive cocci and rods (P ≤ 0.1). However, the incidence of gram-positive rods decreased with the increase in plaque score and probing depths and decrease in black stain score. CONCLUSIONS: Presence of black stains is predominated by various gram-positive and negative rods, and gram-positive cocci. Increase in the plaque score decreases the severity of black stains, thereby increasing the probability of periodontal destruction and dental caries incidence in adult subjects. Further studies are required to corroborate the results.

Effect of periodontal therapy on C-reactive protein levels in gingival crevicular fluid of patients with gingivitis and chronic periodontitis: A clinical and biochemical study.

BACKGROUND AND OBJECTIVES: C-reactive protein (CRP) is a type I acute phase reactant. A number of studies have reported elevated serum CRP levels in periodontitis subjects, which decrease following periodontal therapy. However, the data of interventional studies on gingival crevicular fluid (GCF) levels of CRP is very scarce. The aim of the present study was to evaluate the effect of periodontal therapy on GCF CRP levels in patients with gingivitis and chronic periodontitis. MATERIALS AND METHODS: A total of 60 subjects were included in the study with 20 subjects each in following groups: I-Healthy, II-Gingivitis, III-Mild periodontitis based on community periodontal index scores. Periodontal therapy was performed on Group II and Group III patients. GCF was collected from each subject at baseline and 3 months after periodontal therapy. The collected sample was subjected to biochemical analysis to detect CRP levels by using commercially available chemiluminescence immunoassay kit. RESULTS: The present study demonstrated that the periodontitis group had a higher mean CRP level (2.49 ± 0.47 ng/ml) when compared with the Gingivitis group (1.40 ± 0.32 ng/ml) and Healthy group (0.56 ± 0.20 ng/ml). The mean CRP values after periodontal therapy were found to be reduced to 0.44 ± 0.23 ng/ml in Group II and 1.30 ± 0.36 ng/ml in Group III patients. INTERPRETATION AND CONCLUSION: Within the limitations of this study, it can be concluded that GCF CRP level progressively increases from periodontal health to disease. It can also be stated that there is a decrease in GCF CRP levels with periodontal treatment.

Evaluation of the role of antibiotics in preventing postoperative complication after routine periodontal surgery: A comparative clinical study.

BACKGROUND AND OBJECTIVES: Aim of this randomly controlled clinical study was to evaluate the role of antibiotics to prevent postoperative complications after routine periodontal surgery and also to determine whether their administration improved the surgical outcome. MATERIALS AND METHODS: Forty-five systemically healthy patients with moderate to severe chronic periodontitis requiring flap surgery were enrolled in the study. They were randomly allocated to Amoxicillin, Doxycycline, and control groups. Surgical procedures were carried out with complete asepsis as per the protocol. Postoperative assessment of patient variables like swelling, pain, temperature, infection, ulceration, necrosis, and trismus was performed at intervals of 24 h, 48 h, 1 week, and 3 months. Changes in clinical parameters such as gingival index, plaque index, probing pocket depth, and clinical attachment level were also recorded. RESULTS: There was no incidence of postoperative infection in any of the patients. Patient variables were comparable in all the three groups. Though there was significant improvement in the periodontal parameters in all the groups, no statistically significant result was observed for any group over the others. CONCLUSION: Results of this study showed that when periodontal surgical procedures were performed following strict asepsis, the incidence of clinical infection was not significant among all the three groups, and also that antibiotic administration did not influence the outcome of surgery. Therefore, prophylactic antibiotics for patients who are otherwise healthy administered following routine periodontal surgery to prevent postoperative infection are unnecessary and have no demonstrable additional benefits.