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Biomedical subjects

G Polizzi

Publications and source records attributed to G Polizzi.

31 records · Page 2Linked to original sources
PubMed1988

Receptors for epidermal growth factor and steroid hormones in human breast cancer.

Epidermal growth factor (EGF) seems to play an important role in regulating the proliferation of human breast cancer. Fifty-five primary breast tumors and 7 lymph node metastases were simultaneously assayed for the presence of EGF receptors (EGFR), estrogen receptors (ER), and progesterone receptors (PR). Overall, 42% (23/55) of the tumors were EGFR positive. EGFR were more frequently present in ER- and PR-negative than in ER- and PR-positive tumors. In particular, a negative correlation between EGFR and PR (chi 2 = 6.8; p greater than 0.01) was observed. All metastatic tumors were EGFR negative, and in all cases but 1 the levels of EGFR were higher in metastatic than in primary tumors. Our results suggest the presence of a subclass of breast tumors, the growth of which is primarily regulated by EGF or EGF-like substances rather than by steroid hormones. In this group, not amenable to endocrine therapy, EGF receptors should represent a target for therapeutic intervention.

Breast Neoplasms↗
PubMed1982

Diminished toxicity of methotrexate in CD2F1 mice pretreated with cycloheximide.

Cycloheximide at 100 mg/kg administered intraperitoneally to P388 tumor-bearing CD2F1 mice diminished protein synthesis in the liver, spleen, kidneys, lungs, small intestine and P388 tumor 75 min after administration. Six hours after administration all the above tissues except the tumor no longer demonstrated suppression of protein synthesis. The lethal toxicity of single intraperitoneal doses of methotrexate administered at 1, 3 or 6 h after the cycloheximide was diminished. However, no increase in therapeutic index was achieved with this dose schedule in P388 tumor bearing CD2F1 mice.

Animals↗
PubMedDate not supplied

A 3-year prospective multicenter follow-up report on the immediate and delayed-immediate placement of implants.

A total of 264 implants was placed in 143 patients using different immediate or delayed-immediate implant placement techniques in 12 different centers participating in a prospective multicenter study. The reason for tooth extraction was evaluated; bone quality and quantity were classified; socket depths were registered; and data on implant type, size, and position were collected. One hundred thirty-nine suprastructures were placed on 228 implants in 126 patients. A follow-up evaluation was done on 125 patients after 1 year of loading and on 107 patients after 3 years of loading. Clinical parameters (bleeding or not bleeding, pocket depth, and implant mobility) were evaluated after 1 and 3 years, and the marginal bone level after 1 year of loading was measured on radiographs. Clinical comparisons were performed to evaluate implant loss in relation to implant type, size, position, bone quality and quantity, socket depth, reason for tooth extraction, and placement method. In addition, life table analysis was done for cumulative implant survival rates. There was no clinical difference with respect to socket depth or when comparing the different placement methods. A higher failure rate was found for short implants in the posterior region of the maxilla and when periodontitis was cited as a reason for tooth extraction. Mean marginal bone resorption from the time of loading to the 1-year follow-up was 0.8 mm in the maxilla and 0.5 mm in the mandible. Over a period of 3 years, the implant survival rate was 92.4% in the maxilla and 94.7% in the mandible.

Bone Density↗
PubMedDate not supplied

Clinical application of narrow Brånemark System implants for single-tooth restorations.

Replacing small, single incisors with implants can be esthetically challenging and difficult because of the limited amount of bone. In this investigation, 3.0-mm-diameter implants were used to support 30 single maxillary and mandibular incisors in 21 patients. The implants have been in function for 3 to 7 years, and 29 are still stable. Only 2 complications in the mandibular incisor region have occurred; 1 implant fractured (after 5 years of function) and 1 prosthesis was replaced. The overall success rate is 96.7%. The favorable results and esthetic appearance achieved suggest that replacing small incisors where light occlusal forces are present with narrower implants is a feasible treatment option.

Adolescent↗
PubMedDate not supplied

Osseointegrated implants for single-tooth replacement: progress report from a multicenter prospective study after 3 years.

After 3 years, 82 of the original 92 patients remain in this prospective multicenter study of single-tooth restorations supported by Brånemark implants. Since the 1-year follow-up, 6 more patients have been lost, but no additional implants have failed in those patients examined at the 3-year follow-up visit. After 1 year of function, 97.2% of the implants survived in 88 patients, and between the 1- and 3-year follow-up, 100% survived in 82 patients, giving a 3-year cumulative success rate of 97.2%. No changes were observed in the status of gingivitis, pocket depth, periodontal pocket bleeding index, and tooth and implant mobility from those reported after 1 year. Marginal bone resorption remained at a low level--less than 0.1 mm annually during the second and third years. Abutment screw loosening continued, but at a significantly reduced rate from that reported after 1 year. When used, gold rather than titanium abutment screws remained secure.

Adult↗
PubMedDate not supplied

Osseointegrated implants for single-tooth replacement: a prospective 5-year multicenter study.

One hundred seven Brånemark implants were placed in 92 patients participating in an international multicenter trial on single-implant restorations at seven centers. The patients were followed for 5 years in a prospective study focusing on implant success and crown function. Plaque and gingival indexes, as well as probing depths, were recorded around teeth and implants. The marginal bone level at implants was determined from intraoral radiographs. Only three implants (2.8%) had been lost at the final annual checkup. During the follow-up period, a total of 17 patients dropped out or were excluded because of nonconformity with the protocol. Based on the remaining patients, a total of 86 implants were clinically and radiographically evaluated at the 5-year follow-up period, resulting in a cumulative success rate of 96.6% (71 implants) in the maxillae and 100% (15 implants) in the mandibles. Plaque and gingival indexes showed a similar pattern of good health around both natural teeth and titanium abutments. The marginal bone loss during the 5-year period did not exceed 1 mm as a mean for all implants analyzed. The most frequent complication recorded during the follow-up was loosening of the abutment fixation screw. The outcome of this study indicated that safe and highly predictable results can be obtained for 5 years when Brånemark implants are used to support single-tooth restorations.

Alveolar Bone Loss↗