Butyrate production in engineered Escherichia coli with synthetic scaffolds.

Butyrate pathway was constructed in recombinant Escherichia coli using the genes from Clostridium acetobutylicum and Treponema denticola. However, the pathway constructed from exogenous enzymes did not efficiently convert carbon flux to butyrate. Three steps of the productivity enhancement were attempted in this study. First, pathway engineering to delete metabolic pathways to by-products successfully improved the butyrate production. Second, synthetic scaffold protein that spatially co-localizes enzymes was introduced to improve the efficiency of the heterologous pathway enzymes, resulting in threefold improvement in butyrate production. Finally, further optimizations of inducer concentrations and pH adjustment were tried. The final titer of butyrate was 4.3 and 7.2 g/L under batch and fed-batch cultivation, respectively. This study demonstrated the importance of synthetic scaffold protein as a useful tool for optimization of heterologous butyrate pathway in E. coli.

Bony window approach for a traumatic bone cyst on the mandibular condyle: a case report with long-term follow-up.

Traumatic bone cyst (TBC) occurs preferentially on the mandibular symphysis and body, but rarely on the mandibular condyle. When TBC occurs in the condylar area, it can usually be related with or misdiagnosed as a temporomandibular joint disorder. A 15-year-old female patient visited the Temporomandibular Joint Clinic with a 5-year history of pain and noise localized in the left temporomandibular joint. On imaging, a well demarked oval-shaped radiolucent lesion was observed on the left condyle head. The patient underwent cyst enucleation and repositioning of the bony window on the lateral cortex of the affected condyle head under the impression of subchondral cyst or TBC; however, no cystic membrane was found. The bone defect resolved and showed no recurrence on the serial radiographic postoperative follow-up for 43 months after surgery.

Implant Ball Attachment Fabricated with CAD/CAM to Overcome an Unfavorable Clinical Situation: A Case Report.

The most common complication of implant ball attachments is loss of retention via structural wear. Hence, parallel placement of implants was identified as a prerequisite for long-term success. In this case, although severe angulation was formed between implants due to severe alveolar bone resorption, parallel ball attachments on the implants could be fabricated using computer-aided design/computer-assisted manufacture. This procedure can be a solution when implants are placed with angulation and offers additional advantages such as long-term stability.

Autotransplantation of an impacted premolar using collagen sponge after cyst enucleation.

INTRODUCTION: We report a case of successful autotransplantation of a premolar impacted with a dentigerous cyst and transplanted with collagen plugs for initial support. METHODS: An 18-year-old man had an impacted premolar accompanied with a large dentigerous cyst. The tooth was extracted surgically and transplanted to an edentulous alveolar ridge, and a collagen sponge was inserted to ensure proper healing and initial support. Root canal treatment was performed 3 weeks after the surgery. RESULTS: The previous lesion was healed, and the transplanted tooth was functional without any pathologic signs. CONCLUSIONS: Our protocol provides a viable option for saving an impacted tooth in the case of cyst enucleation.

Diagnosis and treatment of teeth with primary endodontic lesions mimicking periodontal disease: three cases with long-term follow ups.

A tooth with primary endodontic disease that demonstrates a periodontal defect might be extracted because of misdiagnosis as severe periodontal disease or a vertical root fracture. The aim of this case report was to demonstrate the long-term survival of endodontically treated teeth, which had been initially considered unsavable. With meticulous evaluation including the patient's dental history, clinical and radiographic examinations, teeth with primary endodontic lesions could be differentiated and saved after proper root canal treatment. Pain history, vitality test, and radiographic examinations, as well as a general periodontal condition check with periodontal probing on an affected tooth, might be the key methods to differentiate endodontic pathosis from that of periodontal disease.