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Xiao-Guang Liu

Publications and source records attributed to Xiao-Guang Liu.

4 recordsLinked to original sources

[Effects of progressive loading on implants placed into extraction sockets: a preliminary study].

OBJECTIVE: To study the effects of progressive loading on implants placed into extraction sockets. METHODS: Bilateral 3rd, 4th and 2nd premolar of 4 beagle dogs were extracted and the implants were immediately inserted at 0, 14 and 21 days. The progressive loading procedure was conducted after 24 hours. The vertical bone loss (VBL) and the bone/biomaterials reactions were detected by X-ray and SEM. RESULTS: The VBL in control groups was larger than that for the experimental groups at 14, 21 and 28 days (P<0.05). Scan electron microscopy detected that the mineralization speed of experimental groups was many times as faster as the control groups. CONCLUSION: Progressive loading of implants placed into extraction sockets can be performed without disturbing the osseointegration process. The potential of new bone formation in the extraction sockets and the physical strains can congenerously promote osseointegration.

Animals↗

[Surgical factors underlying the recurrence of primary spine tumor].

OBJECTIVE: To find the causes of the spinal primary tumors recurrence in surgical technique. METHODS: From 1989 to 2002, 38 cases of primary spine tumors, including giant cell tumor, osteoblastoma, chondrosarcoma and chordoma with wide resection via a piece-meal fashion. By adopting a retrospective method, the present study investigated the clinical and imaging materials of pre- and post-operation period and those in follow-up. RESULTS: The study included 18 cases of giant cell tumor, 6 osteoblastoma, 6 chondrosarcoma and 8 chordoma. In all cases, 63% of tumors were in cervical and cervicothoracic (C(7)-T(2)) spine; 29% in thoracolumbar (T(4)-L(5)) spine and 8% in sacrum. Tumors involved in multi-segment were 34%. And 71% patients had the tumor in the body and the arch simultaneously. And 71% of tumors formed paraspinal masses, 42% in both sides. The tumors invaded the channel in 58% of the cases. The compartment were invaded in 79% patients. Finally, 32 patients were followed up, from 1.0 approximately 14.9 years, 5.1 years average. Seventeen patients recurred after the surgery, the recurrence rate was 53%. The recurrence rate of giant cell tumor was 35%, osteoblastoma 50%, chondrosarcoma 75%, chordoma 100%. The recurrence rate of tumor in cervical and cervicothoracic spine was 63%, thoracic-lumbar 33%, sacrum 67%. The recurrence rate of multi-segment tumors was 80%, and that of single segment 41%. The recurrence rate of the tumors involving in vertebral body alone or involving the arch simultaneously reached 75% and 55% respectively; the recurrent rate in the arch alone was 33%. The recurrence rate of the tumors involving in vertebral body ranged in different segments. Those growing in cervical and cervicothoracic spine reached 73%; those growing in thoracolumbar spine was only 25%. The recurrence of the tumors without soft masses was 20%, those of single-sided soft masses was 45% and those of double-sided 91%. Among the 17 recurrent patients, 83% of the tumors were in the cervical and cervicothoracic spine. Those extending to the upper cervical and cervicothoracic amounted to 58%. All the 17 recurrent patients had body lesion and paraspinal soft masses. CONCLUSIONS: During the primary spinal tumor operation, that failure to get adequate exposure and full division is thought to be the cause of recurrence. So the precise design before surgery and adequate exposure of the tumor in the surgery is the guarantee of wide excision.

Adolescent↗

Effects of exogenous Ca2+ on the membrane permeability, MDA and SH group content of Alexandrium sp. LC3 under surfactant stress.

The effect of Ca2+ on the removal of Alexandrium sp. LC3 under HDTMAB stress was investigated. The results showed that the toxic effect of HDTMAB on Alexandrium sp. LC3 was significantly reduced in the presence of Ca2 , especially under 4 mmol/L of Ca2+. To understand the underlying mechanism, the SH group and MDA content of the cell membrane and membrane permeability were measured. It was found that the SH content of cell member increased, the MDA content and membrane permeability decreased when Alexandrium sp. was treated with Ca2+ and HDTMAB complex, compared with using HDTMAB only. The data suggested that Ca2+ might promote HDTMAB stress resistance of Alexandrium sp. LC3 by reducing the permeability and increasing the stability of cell membrane.

Animals↗