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Biomedical subjects

A Caputo

Publications and source records attributed to A Caputo.

7 recordsLinked to original sources
PubMed1978

Photoelastic comparison of posterior denture occlusions.

The development of stress patterns was observed within a photoelastic model under complete mandidular dentures. Characteristic stress patterns were related to type of tooth material. Plastic teeth transmitted less force than porcelain teeth. Cusp teeth induced concentrated regions of force within the model that contrasted with the uniform distribution of force observed with flat teeth. The dentist should be aware of the biomechanical problems associated with any posterior denture occlusion in relation to the residual alveolar ridge.

Alveolar Process↗
PubMed1977

Carcinogenicity studies on vinylidene chloride.

Results of a study on Wistar rats regarding a possible carcinogenic effect of vinylidene chloride (VDC) were presented previously by one of the authors. Due to the unclear character of these results, a second inhalation study was initiated with Sprague-Dawley rats. Groups of 60 animals were exposed to 100 and 75 ppm VDC, along with one control group. A final report on the pathological results must await completion of the microscopic examination of the tissues and organs from all the animals. Nevertheless, it seems clear that there is no grossly observable interrelation between tumor production and VDC inhalation.

Animals↗
PubMed1977

Cleavage of damaged DNA by an enzymatic activity from human fibroblasts.

An endonuclease activity isolated from normal, Xeroderma Pigmentosum and De Sanctis-Cacchione fibroblasts by DNA-cellulose chromatography has been evaluated by means of sedimentation analysis both in alkaline and neutral sucrose gradients. The partially purified enzyme is active at pH 7.5 in presence of Mg++ and cleaves UV-irradiated and alkylated DNA. Under identical experimental conditions, the enzyme is not active on untreated, depurinated and heat-denaturated DNA. The specificity on pyrimidine dimers has been further investigated to understand the mechanism of action of the enzyme.

Alkylation↗
PubMed1976

Antibodies to BK virus structural and tumor antigens in human sera from normal persons and from patients with various diseases, including neoplasia.

Sera from 1,279 patients with various diseases were examined for the presence of antibodies to BK virus (BKV) capsid antigens. The percentage of positive sera was comparable in all the diseases except rheumatoid arthritis and chronic nephropathies, where a slightly higher prevalence was found. Sera from 952 patients with tumors were examined for the presence of antibodies to BKV tumor and capsid antigens in comparison with a matched control group of 501 blood donors. Sera from 11 tumor patients (1.15%) and from 4 normal controls (0.80%) had antibodies to BKV tumor antigen. No higher prevalence of antibodies to BKV capsid antigens was found in any cancer type except in carcinomas of the urinary bladder, where the percentage of positive sera and of sera with high titers was higher than in other groups. BKV infection is discussed in relation to its possible connection with human non-neoplastic diseases as well as with human tumors and to its activation under conditions of immunosuppressive therapy.

Antibodies, Viral↗
PubMed1976

Importance of experimental data for the improvement of the therapeutical effect of bleomycin.

The intimate mechanism of action of bleomycin has been extensively studied at molecular and cellular level. From the analysis of dose-response curves, different hypotheses have been formulated, and the importance and the extent of DNA repairability has been emphasized in correlation with the different phases of the cell cycle. Sensitivity to bleomycin depends on the fixation of DNA damage which occurs when damaged sites become involved in replication before they can be repaired.

Animals↗
PubMedDate not supplied

An evaluation of primary enamel pretreatments and their effects on resin retention.

The effects of various enamel pretreatments on bond strengths between primary enamel and resin were investigated. Pretreatments included: removal of the outer enamel surface, varied exposure to phosphoric acid, and the use of an organic coupling agent. Results indicated highest bond strengths utilizing acid pretreatments and an organic coupling agent.

Acid Etching, Dental↗