Tumors are classified into two major categories,benign and malignant.One main difference between malignant and benign tumors is their tendency to metastasize and recur.The metastasis itself is an ominous sign for prognosis and responsible for most cancer deaths.The metastatic "cascade" comprises a lot of steps,including escape from the primary tumor site,penetration of local stroma,entry of local vascular or lymphatic vessels,aggregation with platelets,interaction with and adhesion to distant endothelia,extravasation,recolonization,and expansion,all the time avoiding effective immune clearance and being able to survive.It has now been shown to contain stem cell-like cells called cancer stem cells(CSC) in several solid tumors.Although generally rare,these cells appear to be highly tumorigenic and may drive tumor formation and mediate tumor metastasis.

Angiogenesis is an important feature of malignant neoplasm and plays an essential role in the genesis,growth and metastasis of tumors. CT perfusion imaging (CTPI),as one of the functional imaging techniques reflecting neovascularity of neoplasm,perfectly combines anatomical imaging with physiological information and can be used in a range of clinical areas,such as differentiation between benign and malignant lesions,early detection of malignancy or metastasis,prediction of tumor behavior and the assessment of responses to therapies. Many researches have been done on perfusion CT in tumors of the brain,thyroid gland,salivary gland,mammary gland,lungs,liver,esophagus,kidney,colorectum,and so on. The present article reviews the basic principles of perfusion CT and its clinical application in tumors.

Objective To assess the radiographic and clinical outcomes of opening osteotomy supplemented with autologous anterior strut grafting and internal fixation through posterior-lateral approach in the treatment of unstable thoracolumbar fractures. MethodsFrom January 2008 through March 2010,a consecutive series of 13 thoracolumbar fractures were managed with opening osteotomy supplemented with autologous anterior strut grafting and internal fixation through posterior-lateral approach.They were 8 males and 5 females,aged from 20 to 58 years(median age,37.2 years).The fractures happened at T11 in 2 cases,at T12 in 3 cases,at L1 in 6 cases and at L2 in 2 cases.The autologous ilium was used for all the anterior strut grafts.The time from injury to surgery ranged from 21 days to 2 years (average,8 months).The mean heights of anterior and posterior borders of the vertebral body,the cobb angles and treatment-related complications were compared between preoperation and postoperation and the patients' satisfaction was assessed with the visual analogue scale(VAS).Statistical analyses were performed with the paried-sample t test. Results The patients were followed for 12 to 36 months (average,17 months).The latest follow-up radiographs were available for all patients.The mean heights of anterior and posterior borders of the vertebral body restored respectively from preoperative 21.02 ± 3.02 cm and 31.34 ± 5.18 cm to postoperative 31.88 ±3.46 cm and 33.75 ± 3.66 cm.The mean cobb angle was corrected from preoperative 28.46° ± 5.81° to postoperative 4.62° ± 3.48°.The mean VAS score decreased from preoperative 7.63 ± 0.72 to 1.39 ± 1.02 at the final follow-up.There were significant differences between preoperation and postoperation in the radiographic and clinical outcomes ( P ＜ 0.05).No mortality or major complications occurred involving large blood vessels or abdominal viscera or internal organs. Conclusion The opening osteotomy supplemented with autologous anterior strut grafting and internal fixation through posterior-lateral approach is safe and effective for old unstable thoracolumbar fractures.

OBJECTIVETo observe the fibrosis of skin after damage to the fat dome structure in skin of pig.

METHODSTotally 4 pieces of skin grafts of intermediate thickness in the size of 5 cm × 5 cm were obtained from both sides beside the spine of back in each of the 4 female red Duroc pigs with pedicle on one side with Humby knife performed by burn specialists, who were rich in clinical experience. These skin grafts were assigned as thin dermis group (TD). Pedicled tissue grafts in the size of 5 cm × 5 cm with the thickness of 1.5 mm were obtained within the wounds resulted from former incision with the same method mentioned above, and these tissue grafts were set as fat dome group (FD). The above-mentioned two groups of skin grafts were sutured back in situ immediately after completion of the former procedures. On post surgery day (PSD) 7, 14, and 21, 5 wounds were respectively selected according to the random number table for gross observation of the surgical areas. Tissue samples were obtained from corresponding surgical area deep to the deep fascia after gross observation at above-mentioned time points. Some of the tissue samples were used for observation of distribution of collagen fibers in the regions of operation of both groups of skin grafts with HE staining, and the breadth of fibrosis was measured; some of the tissue samples were used for observation of distribution of type I or III collagen fibers in the regions of incision of both two groups of skin grafts with Sirius red staining. Data were processed with two independent sample t test.

RESULTSA little scab on the edge of wounds was observed on PSD 7; all the wounds were healed on PSD 14; a few hairs were observed growing in the surgical area on PSD 21. HE staining showed that traces of incision were observed in the superficial layer of dermis and at the junction between dermis and fat dome at each time point; profuse hyperplasia of collagen fibers with parallel and orderly arrangement were observed in the region of incision of skin grafts in groups TD and FD at each time point. The breadth of fibrosis of the region of incision of skin grafts was respectively (251 ± 31), (240 ± 3 7), and (342 ± 69) µm in group TD, (239 ± 36), (286 ± 61), and (332 ± 28) µm in group FD on PSD 7, 14, 21, without significantly statistical difference (with t values respectively 0.750, -1.971, and 0.375, P values above 0.05). Sirius red staining showed that large amount of type III collagen fibers and small amount of type I collagen fibers arranging parallelly were present in the region of incision of skin grafts in groups TD and FD at each time point.

CONCLUSIONSUnder the circumstances of relatively intact restoration of dermal tissue, no excessive fibrosis was observed after simple incisional injury of fat dome in skin of pig.

Animals ; Burns ; surgery ; Dermis ; surgery ; transplantation ; Female ; Fibrosis ; complications ; Graft Survival ; Male ; Skin ; Skin Transplantation ; methods ; Skin, Artificial ; Swine ; Wound Healing