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Biomedical subjects

L Sbordone

Publications and source records attributed to L Sbordone.

At least 55 records · Page 3Linked to original sources
PubMed1977

Biochemical and regulatory properties of Escherichia coli K-12 hisT mutants.

Escherichia coli K-12 hisT mutants were isolated, and their properties were studied. These mutants are derepressed for the histidine operon, map close to the purF locus at about 49.5 min on the E. coli linkage map, and lack pseudouridylate synthetase activity. The defect in this enzyme leads to the absence of pseudouridines in the anticodon loop of several transfer ribonucleic acid species, as evidenced by the altered elution profile on reversed-phase chromatography and resistance to amino acid analogues. Finally, the hisT mutants studied have a reduced growth rate that appears to be linked to hisT, although it is not known whether it is due to the same mutation. The normal generation time can be restored by supplementing the medium with adenine, uracil, and isoleucine.

Adenine↗
PubMedDate not supplied

Tetracycline fibres used to control bacterial infection during guided tissue regeneration (GTR).

AIMS: The colonization of suspected periodontal pathogens during the healing of periodontal defects treated by guided tissue regeneration (GTR) with e-PTFE membranes and tetracycline fibers was investigated. METHODS: Fifteen patients, each with one pair of angular periodontal bone defects of comparable size and morphology were recruited for the study. In a matched-pair study design, the test defects were treated with e-PTFE membranes in combination with tetracycline fibers, while control defects were treated with e-PTFE membranes alone. Microbiological specimens were taken from control as well as from test sites preoperatively (T0), intraoperatively (T1), two weeks after surgery (T2) and from membranes at time of removal (T3). Cultural methods were used to identify the following species: Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Fusobacterium nucleatum (Fn) and Actinobacillus actinomicetemcomitans (Aa). RESULTS: At baseline and T1, none of the suspected periodontal pathogens were detected at test or control sites. Levels of P. intermedia and F. nucleatum, as mean percentages of total culturable microflora, were detected at levels significantly higher in control sites than test sites at times T2 and T3. CONCLUSIONS: Findings from this study suggest that e-PTFE membranes are frequently colonized by periodontal pathogens, and that bacterial colonization of healing sites after GTR procedures can be kept under control with a controlled delivery system releasing tetracycline.

Aggregatibacter actinomycetemcomitans↗
PubMedDate not supplied

[Periodontal osseous surgery: osteoplasty and osteotomy].

Elimination of the periodontal pocket is a prime objective of periodontal therapy. Normally the gingiva is consistent with the underlying bone, and aberration in gingival form can be corrected by gingivectomy or gingivoplasty if the gingiva is supported by good bony architecture. If periodontitis has caused marginal irregularities or septal deformities the complete elimination of the periodontal pocket is done by osteoplasty or osteoectomy. The Authors through a review of the literature have examined these surgical techniques.

Alveolar Process↗