甲状旁腺激素对大鼠牵张成骨过程中O NC、OPN、C-FOS、COL1、VEGF、RUNX2、ALP基因表达的影响

目的：探讨甲状旁腺激素（PTH）对大鼠牵张成骨（DO）过程中ONC、OPN、C-FOS、COL1、VEGF、RUNX2、ALP基因表达的影响。方法30只雄性大鼠制备大鼠下颌骨DO模型。随机分5组，每组6只。第1组（只有牵张无PTH），术后8周取材，应用HE染色及微CT检测，以确定成骨情况。第2组（有牵张无PTH），第3组（有牵张有PTH），第4组（无牵张有PTH），第5组（对照组：无牵张无PTH）。2、3、4组及对照组术后1周取材，RT-PCR测定ONC、OPN、C-FOS、COL1、VEGF、RUNX2、ALP基因的表达。结果第1组，新骨形成，骨质充满牵张区，骨质连续，大鼠建模成功。RT-PCR检测结果显示，2、3、4组与对照组比较，OPN、COL1、RUNX2、ALP基因表达有明显提高（P＜0．05），其中第3组最为明显。ONC、C-FOS、VEGF基因2、3、4组与对照组比较差异无统计学意义（P＞0．05）。结论 PTH在 DO 过程中，间歇性给以 PTH的作用只有在牵张期发挥作用，其对 OPN、COL1、RUNX2、ALP基因表达能够获得理想的协同作用。     

Ethyl lactate as a potential green solvent to extract hydrophilic (polar) and lipophilic (non-polar) phytonutrients simultaneously from fruit and vegetable by-products

Phytonutrients extracted from natural resources are receiving much attention among researchers due to their highly antioxidative characteristics which prevent several degenerative diseases including cardiovascular diseases and cancers. These nutraceutical compounds can be used in food, pharmaceutical and cosmetic products as natural antioxidants, preservatives, colourants and functional foods. Huge volume of food wastes are generated from the processing industry and these low-value food residues are rich in various phytonutrients worth recovering. This approach of valorisation reduces the generation of food wastes and is cost-effective considering the cheap feedstock, reduced waste management expenses and high market value of extracted compounds. In light of the health and safety risks posed by commonly used organic extraction solvents derived from the petrochemical industry, there is a need to recover the phytonutrients using green, sustainable and efficient solvents that are safe for human consumption. This work discusses ethyl lactate as a safe, green, efficient and potentially cheap solvent to recover phytonutrients from fruit and vegetable by-products. Ethyl lactate is compared with other organic solvents commonly used from the aspects of safety, environmental impacts and efficiency. Current challenges when employing ethyl lactate are also discussed.     

Outflow of aqueous humor following cyclodialysis or ciliochoroidal detachment in rabbit

Cyclodialysis and ciliochoroidal detachment were performed in three eyes of three rabbits and in three eyes of another three rabbits, respectively. After aspiration of the aqueous humor, 0.1 ml of 10% sodium fluorescein was injected intracamerally, and the eyeball was enucleated between 30 minutes and one hour after injection and prepared for fluorescence microscopy. Sodium fluorescein concentrations in the supraciliary space were much greater in the group with cyclodialysis or ciliochoroidal detachment than in the normal control group. These results suggest that (1) in the eye with cyclodialysis, the aqueous humor may freely gain access to the supraciliary space through the cleft between the anterior chamber and the supraciliary space and then be removed rapidly and (2) in the eye with ciliochoroidal detachment, the aqueous humor may pass through the uveoscleral outflow pathway.     

Fat and water separation in balanced steady-state free precession using the Dixon method.

In this work the feasibility of separating fat and water signals using the balanced steady-state free precession (SSFP) technique is demonstrated. The technique is based on the observation (Scheffler and Hennig, Magnetic Resonance in Medicine 2003;49:395-397) that at the nominal values of TE = TR/2 in SSFP imaging, phase coherence can be achieved at essentially only two orientations (0 degrees and 180 degrees ) relative to the RF pulses in the rotating frame, under the assumption of TR < T2, and independently of the SSFP angle. This property allows in-phase and out-of-phase SSFP images to be obtained by proper choices of the center frequency offset, and thus allows the Dixon subtraction method to be utilized for effective fat-water separation. The TR and frequency offset for optimal fat-water separation are derived from theories. Experimental results from healthy subjects, using a 3.0 Tesla system, show that nearly complete fat suppression can be accomplished.     

Partially de-epithelialised and buried V-Y advancement flap for reconstruction of sacrococcygeal and ischial defects.

Defects in the sacrococcygeal and ischial soft tissues can be treated with gluteus maximus and posterior thigh V-Y advancement flaps. However, late complications include recurrence and dehiscence of the suture line. Increasing the amount of the soft tissues over the bony prominences and multilayered closure may have an advantage for long-term durability. We modified the V-Y advancement technique by de-epithelialising the medial parts of the flap and burying them under the opposing edge of the wound or the flap. Sixteen patients with various defects of the sacrococcygeal and ischial soft tissues were operated on using this technique. All the flaps healed well with no partial or complete loss of the flap. Three patients developed complications. The main advantage of our technique is the use of healthy tissues to obliterate the dead spaces under the edges of the wound or the opposing flap. In this way, not only the defect in the skin but the defect in the subcutaneous tissue, with its iceberg tip at the surface, is treated effectively. To have an additional layer of tissue between the bone and the superficial tissues provides an extra cushion of soft tissue and avoids putting the suture line directly over the bony prominences. We used this modification safely for both unilateral and bilateral flaps. It could also be used successfully in other parts of the body.     

Liver and lung resection for colorectal metastasis

Aim: To examine the survival benefit of liver and lung resection for colorectal metastasis and the potential prognostic factors that affect patient survival. Methods: All patients who had resection of lung or liver metastasis for colorectal metastasis in Queen Elizabeth Hospital, Hong Kong from 1995 to 2004 were retrospectively reviewed. The overall and disease‐free survival was analysed, in particularly between liver and lung metastasis. All factors that may have affected the survival were entered into Cox's proportional hazards regression model to identify significant variables associated with survival. Results: At 5 years, the overall survival of patients who had resection of lung and liver metastasis was 44% and 38%, respectively; the disease‐free survival was 26% and 24%, respectively. Overall and disease‐free survival of patients with resection of lung metastasis was comparable to those with resection of liver metastasis. The differentiations of primary tumour and time to metastasis were shown to be significant prognostic factors influencing overall survival. Those patients with systemic chemotherapy after resection of colorectal metastasis demonstrated a significantly higher probability of overall survival. Conclusion: Resection of lung and liver metastases from colorectal origin was safe and both procedures improved survival. The use of chemotherapy after resection of metastasis significantly improved the overall survival.