Search

With the cutting-grinding technique (Exakt System) it is possible to obtain sections with a width of less than 10 microns of specimens such as teeth, crowns, bridges, implants, mineralized structures, which cannot be cut with routine histological techniques. In the present paper the authors study the efficacy of this technique in hard dental tissues.

The authors report 2 cases of leiomyosarcoma of the lips occurring in two elderly women. They review the incidence, the symptoms, the microscopic appearance, the differential diagnosis, the treatment and prognosis of this kind of tumor. It is a highly malignant neoplasm with a high rate of recurrences and metastases and should be treated with a radical resection and radical neck dissection when there is a metastatic node.

The Authors have studied the efficacy of the sealing effect of thermomechanical compaction of guttapercha according to McSpadden with an in vitro analysis on undecalcified tooth sections and with a clinical evaluation of ten patients with periapical lesions. The analysis of the results has shown a good sealing capacity of the McSpadden technique.

Benign cementoblastoma is a rare odontogenic tumour localized in the jaws of young people. Benign cementoblastoma has characteristic radiologic and microscopic features and it appears to be fused to the tooth roots. The most important differential diagnosis is-with a benign osteoblastoma. The tumor should be enucleated and the teeth extracted. This case represents only the third reported case of a benign cementoblastoma associated with a third molar.

The purpose of this study was to study the efficacy of an endodontic cleansing procedure to remove the pulp and the dentin from the root canal system with a new endodontic instrument proposed by J.M. Laurichesse, the Shaper.

17 diterpenoids isolated from brown algae of the family DICTYOTACEAE have been evaluated for molluscicidal and antifungal activity. Significant molluscicidal activity is exhibited by the two geometrical isomers 9 and 10. The assessment of structure-activity relationships has been considered.

Two new dolabellane derivatives (5 and 6) have been isolated from a Dictyota sp. and their structure, including absolute configuration, has been determined on the basis of spectral studies and chemical correlations.

The importance of sealing small vessels by electrocoagulation in microsurgery is well known. In practice, the reliability of both short and long time results obtained with common and bipolar forceps with radiofrequency application is variable, particularly when encrusted coagulations adhere to the forceps tips and there is danger of damaging the vessel when the forceps are withdrawn. The coagulation process involves a sudden change in tissue characteristics, that occurs within a narrow temperature range, closely following the pattern of the applied current and is only modified by heat dissipation to the cooler parts, such as the forceps tips. Keeping these principles in mind, we developed an improved device which provides: A well-balanced current flow between the tips, which is unaffected by wiring, distributed capacitance and current leakage of the electrocoagulator ; a time-dependent heating pattern that coagulates only the core of the clamped tissue.

A novel ether lipid, (-)-(R)-1-O-geranylgeranylglycerol, has been isolated from the brown alga Dilophus fasciola and its structure proved by spectroscopic methods and chemical degradation.

The distribution of gibberellin- and cytokinin-like activities in twenty-one species of mediterranean algae belonging to Phaeophyta and Rhodophyta has been investigated. Fractions containing each of these activities have been obtained by partitioning aqueous-methanolic extracts of algae against ethyl acetate and butanol successively at different pH values. The stimulation or inhibition of amaranthin synthesis in Amaranthus sp. seedlings have been used a biological tests to assay the cytokinin- or gibberellin-like activities respectively. One or both these two hormonal activities have been detected in all species examined. While cytokinin-like activity has been found with the same frequency in the two phyla, the gibberellin-like activity was less frequent in Phaeophyta.

From fruit bodies of the basidiomycete Suillus granulatus the tetraprenylphenols 2-6 were isolated. Their structures were elucidated by means of chemical and spectroscopic methods. Compounds 4 and 5 possess antimicrobial properties.