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OBJECTIVE: Alveolar distraction is a relatively novel procedure by which alveolar bone and underlying mucosa are regenerated. The low predictability of other vertical or horizontal bone regeneration methods has increased interest in this promising technique. This article was designed to review published clinical and experimental results on alveolar distraction, including basic research in other disciplines (maxillofacial and orthopedic distraction) related to or with influence on alveolar distraction. STUDY DESIGN: A review of the international literature was performed to summarize results of clinical and experimental studies on alveolar distraction and on distraction at other anatomical sites that contribute important findings on tissue biology, molecular mechanisms, and other factors that influence and participate in the alveolar distraction process. RESULTS: Research into alveolar distraction has addressed the latency phase, distraction phase, and consolidation phase, yielding highly variable results. Little experimental research has been carried out on this procedure, and most publications are clinical studies with a short follow-up period. Published studies have reported a high rate of complications, attributable to our current lack of understanding of the process. CONCLUSIONS: Definitive conclusions on alveolar distraction are hampered by the lack of clinical and experimental studies to date. Greater knowledge of the factors that influence the distraction process will lead to a more predictable and efficacious distraction technique and a better distractor design.  相似文献   
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Background  Nonmelanoma skin cancer (NMSC) has been linked to cutaneous human papillomaviruses of the genus beta (betaPV).
Objectives  We sought to assess the presence of betaPV in NMSC biopsies from a group of Scottish skin cancer patients, both immunocompetent (IC) patients and immunosuppressed (IS) organ transplant recipients.
Methods  One hundred and twenty-one paraffin-embedded skin tumours (27 actinic keratosis, 41 intraepidermal carcinoma, 53 squamous cell carcinoma) and 11 normal skin samples were analysed for the presence of betaPV by a polymerase chain reaction–reverse hybridization assay designed to detect the presence of the 25 known betaPV genotypes.
Results  In IC patients, betaPV was detected in 30 of 59 (51%) tumours and two of 11 (18%) normal skin samples ( P  =   0·046). In IS patients, betaPV was found in 27 of 62 (44%) tumours; no normal skin samples were available for comparison. The most frequently found genotypes were HPV-24, HPV-15 and HPV-38. Of those tumours infected with betaPV, 28 of 57 (49%) were infected with more than one genotype (range 2–8). Tumours from IS patients were from a younger age group (mean age 57·4 years) than IC patients (mean age 73·8 years). Multiple infections were more common in tumours from IC patients (21 of 30; 70%) compared with those from IS patients (seven of 27; 26%) ( P  <   0·001). In the IC group, age did not appear to influence the distribution of single and multiple infections whereas in IS patients the proportion of multiple infections to single infections increased with age. There were no multiple infections in normal skin.
Conclusions  A wide spectrum of betaPV types was detected in our samples. Further characterization of betaPV in vivo is needed in order to determine the mechanisms by which the virus contributes to cutaneous carcinogenesis.  相似文献   
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We have examined immunohistochemically the presence of human chorionic gonadotrophin (hCG) in 29 esophageal carcinomas: 24 squamous cell carcinomas, 2 adenocarcinomas, 2 adenoid cystic carcinomas and 1 adenosquamous carcinoma. In hCG-positive tumors, the presence of human placental lactogen (hPL) and pregnancy-specific beta-1 glycoprotein (SP-1) was also assessed. HCG immunoreactive cells were found in 5 squamous cell carcinomas (21%) and in none of 5 non-squamous cell tumors. The hCG positive cells were found in the most infiltrating areas of the tumors where poorly differentiated and pleomorphic cells predominated. The positive tumors were 4 poorly differentiated (31%) and one moderately differentiated carcinoma (12%). Four out of 10 cases (40%) with lymph node metastases had hCG in the primary tumor, whereas only one out of 11 cases (9%) without metastases was hCG positive. HPL and SP-1 were found in two cases. These placental proteins were detected in similar areas than hCG but the number of hPL and SP-1 immunoreactive cells was lower than hCG positive cells. SP-1 was also seen in areas of squamous cell differentiation negative for hCG. None of these two cases showed trophoblastic differentiation.  相似文献   
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Abdominal abnormalities in AIDS: detection at US in a large population   总被引:1,自引:0,他引:1  
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