Gingival crevicular fluid can degrade Emdogain and inhibit Emdogain‐induced proliferation of periodontal ligament fibroblasts

Laaksonen M, Salo T, Vardar‐Sengul S, Atilla G, Han Saygan B, Simmer JP, Baylas H, Sorsa T. Gingival crevicular fluid can degrade Emdogain and inhibit Emdogain‐induced proliferation of periodontal ligament fibroblasts. J Periodont Res 2010; 45: 353–360. © 2009 The Authors. Journal compilation © 2009 Blackwell Munksgaard Background and Objective: Emdogain^® (EMD), consisting mostly of amelogenin, is used in periodontal therapy to regenerate lost connective tissue. Emdogain is applied onto periodontally affected root surfaces, where it becomes exposed to proteolytic enzymes. In this study, we aimed to find out whether gingival crevicular fluid or matrix metalloproteinases (MMPs) could degrade EMD, and whether this degradation has consequences for in vitro cell proliferation. Material and Methods: We studied the effects of 156 gingival crevicular fluid samples collected from subjects with different stages of periodontal disease and from healthy control subjects and the effects of MMP‐1, ‐2, ‐8, ‐9, ‐13 and ‐14 on the degradation of EMD using EMD‐embedded zymography. The effects of gingival crevicular fluid with or without EMD and the effects of amelogenin on the proliferation of cultured periodontal ligament fibroblasts were studied by cell proliferation enzyme‐linked immunosorbent assay kit. Results: Degradation of Emdogain induced by gingival crevicular fluid was greater in samples from all stages of periodontal diseases compared with healthy control samples. Of the MMPs studied, only MMP‐2 and MMP‐8 showed limited EMD‐degrading activities. One hundred micrograms per millilitre of EMD increased proliferation of periodontal ligament fibroblasts on average by 24% (confidence interval 0.60–0.64) and at 200 μg/mL by 30% (confidence interval 0.62–0.68) compared with control fibroblasts (confidence interval 0.48–0.52). However, gingival crevicular fluid (10 μg/mL) together with 100 μg/mL EMD induced the proliferation only by 6% (confidence interval 0.51–0.55) and with 200 μg/mL EMD by 12% (confidence interval 0.54–0.58). Amelogenin at 200 μg/mL decreased the proliferation of periodontal ligament fibroblasts by 54% (confidence interval 0.22–0.25). Conclusion: We suggest that diseased gingival crevicular fluid containing various proteases leads to degradation of EMD and decreased proliferation of periodontal ligament fibroblasts.     

Validity of a Surveillance System for Childhood Injuries in a Rural Block of Tamilnadu

Background:

Childhood injuries are increasingly getting the attention of public health experts following WHO''s report on global burden of diseases. Surveillance is an important component of control of any disease and effectiveness of the surveillance system depends upon completeness of the information about occurrence of the health related events to the public health authorities.

Aims:

This study aimed to set up a surveillance system for childhood injuries and validate it by a survey and thereafter estimate the incidence of childhood injuries using capture recapture method.

Settings and Design:

Observational study design.

Materials and Methods:

Passive surveillance system for childhood injuries was created for 26,811 children of less than fourteen years of Kaniyambadi block and it was validated by cross sectional study at the end of surveillance period. Using these two independent information systems, capture recapture method was applied to find out the possible incidence of injuries in the given population at a given period of time.

Statistics:

Chi square, Lincoln Peterson formula for capture re-capture method.

Results:

Surveillance and survey for childhood injuries identified 13.59/1000 child-years (CI: 11.86 - 15.32) and 341.89/1000 child-years (CI: 254.46-429.33) of injury rates, respectively.

Conclusion:

Passive surveillance system underreports childhood injuries markedly but it does identify childhood injuries of serious nature.     

The Cost of Ignoring Acute Cholecystectomy

INTRODUCTION

Biliary symptoms whilst awaiting elective cholecystectomy are common, resulting in hospital admission, further investigation and increased hospital costs. Immediate cholecystectomy during the first admission is safe and effective, even when performed laparoscopically, but acute laparoscopic cholecystectomy has only recently become increasingly commonplace in the UK. This study was designed to quantify this problem in our hospital and its cost implications.

PATIENTS AND METHODS

The case notes of all patients undergoing laparoscopic cholecystectomy in our hospital between January 2004 and June 2005 were examined for details of hospital admissions with biliary symptoms or complications whilst waiting for elective cholecystectomy. Additional bed occupancy and radiological investigations were recorded and these costs to the trust calculated. We compared the potential tariff income to the hospital trust for the actual management of these patients and if a policy of acute laparoscopic cholecystectomy on first admission were in place.

RESULTS

In the 18-month study period, 259 patients (202 females) underwent laparoscopic cholecystectomy. Of these, 147 presented as out-patients and only 11% required hospital admission because of biliary symptoms whilst waiting for elective surgery. There were 112 patients who initially presented acutely and were managed conservatively. Twenty-four patients were re-admitted 37 times, which utilised 231 hospital bed-days and repeat investigations costing over £40,000. There would have been a marginal increase in tariff income if a policy of acute laparoscopic cholecystectomy had been in place.

CONCLUSIONS

Adoption of a policy of acute laparoscopic cholecystectomy on the index admission would result in substantial cost savings to the trust, reduce elective cholecystectomy waiting times and increase tariff income.     

Intravenous levetiracetam for treatment of neonatal seizures

In this case series we report on eight neonates with refractory seizures who received intravenous levetiracetam when seizures did not respond to two or more conventional anticonvulsants. Six of the eight neonates had an excellent response with either cessation, or reduction in seizures by at least 80%. One neonate showed a partial response while one did not have any reduction in seizure frequency. We did not encounter any adverse effects that could be attributable to levetiracetam.     

Induction of bone formation in biphasic calcium phosphate scaffolds by bone morphogenetic protein‐2 and primary osteoblasts

Bone tissue engineering strategies mainly depend on porous scaffold materials. In this study, novel biphasic calcium phosphate (BCP) matrices were generated by 3D‐printing. High porosity was achieved by starch consolidation. This study aimed to characterise the porous BCP‐scaffold properties and interactions of osteogenic cells and growth factors under in vivo conditions. Five differently treated constructs were implanted subcutaneously in syngeneic rats: plain BCP constructs (group A), constructs pre‐treated with BMP‐2 (group B; 1.6 µg BMP‐2 per scaffold), seeded with primary osteoblasts (OB) (group C), seeded with OB and BMP‐2 (group D) and constructs seeded with OB and pre‐cultivated in a flow bioreactor for 6 weeks (group E). After 2, 4 and 6 weeks, specimens were explanted and subjected to histological and molecular biological analyses. Explanted scaffolds were invaded by fibrovascular tissue without significant foreign body reactions. Morphometric analysis demonstrated significantly increased bone formation in samples from group D (OB + BMP‐2) compared to all other groups. Samples from groups B‐E displayed significant mRNA expression of bone‐specific genes after 6 weeks. Pre‐cultivation in the flow bioreactor (group E) induced bone formation comparable with group B. In this study, differences in bone distribution between samples with BMP‐2 or osteoblasts could be observed. In conclusion, combination of osteoblasts and BMP‐2 synergistically enhanced bone formation in novel ceramic scaffolds. These results provide the basis for further experiments in orthotopic defect models with a focus on future applications in orthopaedic and reconstructive surgery. Copyright © 2012 John Wiley & Sons, Ltd.     

Characterization of Periodontal Structures of Enamelin‐Null Mice

Background: Enamelin‐null (ENAM^?/?) mice have no enamel. When characterizing ENAM^?/? mice, alveolar bone height reduction was observed, and it was hypothesized that enamel defects combined with diet are associated with the periodontal changes of ENAM^?/?mice. The aim of the present study is to compare the dimension of interradicular bone of ENAM^?/? (knock‐out [KO]) with wild‐type (WT) mice, maintained on hard (HC) or soft (SC) chow. Methods: A total of 100 animals divided into four groups were studied at 3, 8, and 24 weeks of age: 1) KO/HC; 2) KO/SC; 3) WT/HC; and 4) WT/SC. Microcomputed tomography was performed, and the following measurements were made between mandibular first (M1) and second (M2) molars: relative alveolar bone height (RBH), crestal bone width (CBW), bone volume (BV), bone mineral content (BMC), and bone mineral density (BMD). The position of M1 and M2 in relation to the inferior border of the mandible was also determined at 24 weeks. All variables were analyzed by one‐way analysis of variance and Dunnett test for pairwise comparisons. Morphologic analyses were conducted on hematoxylin and eosin–stained sections. Results: Radiographically, the enamel layer was absent in ENAM^?/? mice. Interproximal open contacts were observed exclusively in ENAM^?/? mice, and the prevalence decreased over time, suggesting that a shifting of tooth position had occurred. Additionally, in the two ENAM^?/? groups, RBH was significantly lower at 8 and 24 weeks (P <0.02); CBW, BV, and BMC were significantly less (P <0.05) at 24 weeks. No differences in BMD were found among the four groups. The molars migrated to a more coronal position in ENAM^?/? mice and mice on HC. Histologic findings were consistent with radiographic observations. After eruption, the junctional epithelium was less organized in ENAM^?/? mice. Conclusion: The interdental bone density was not affected in the absence of enamelin, but its volume was, which is likely a consequence of alternations in tooth position.