Objective To assess the diagnostic value of delayed CT contrast enhancement patterns in hilar cholangiocarcinoma based on two phased dynamic incremental CT scanning. Methods Fifty two patients with suspected hilar tumor and bile duct obstruction underwent spiral CT scan. The scan time for one revolution of the X ray tube was 1 second. To elucidate the delay time for optimal imaging, all proved cholangiocarcinoma with delayed (6、8、10、15、20、30 minutes) post equilibrium phase contrast enhanced CT scans were acquired with unenhanced, dynamic contrast enhanced, and delayed images. Degree of delayed enhancement was compared with that of surrounding liver parenchyma. Results (1) 8～15 minutes after IV injection of contrast material was the delay time for optimal imaging. (2) Of 29 cholangiocarcinomas, the early CT showed hypoattenuating (lower than that of liver parenchyma) in 23 tumors, isoattenuating (equal to that of the liver) in 4 tumors, and hyperattenuating (higher than that of liver) in 2 tumors. The delayed CT scan showed isoattenuating in 8 tumors, hyperattenuating in 21 tumors, and no hypoattenuating. Most of delay imaging of hilar cholangiocarcinoma may appear hyperattenuating ( U=-4.307 3, P

Objective To describe CT and MRI imaging findings of retinal hamartomas with tuberous sclerosis and evaluate their clinical value.Design Retrospective case series.Participants 7 patients of tuberous sclerosis complex(TSC) who have ocular lesions found with CT and MRI examination.Methods 7 patients with tuberous sclerosis were diagnosed by clinical data and head CT.The size,morphology,density and enhancing situation of the retinal lesions were observed with CT and MRI,as while as with direct or indirect fundoscopy.Main Outcome Measures CT and MRI features of ocular lesions.Results 7 cases displayed intracranial calcification and/or non-calcified tubercles,situating in subendyma(7 cases,accounting for 100%) by head CT.Orbital CT and MRI showed 4 cases (57.1%) of flat retinal hamartomas 3 cases(42.9%) of retinal lobular and nodular hamartomas,2 cases(28.6%) scattered calcification patches in hamartoma,and 2 cases(28.6%) of nanophthalmos.The lesions displayed unenhancement on contrast-enhanced MR images in 7 cases(100%).There was 1 case(14.3%) of progressive retinal astrocytic hamartoma.Conclusion The examination of CT and MRI may find the bigger retinal hamartomas,which can play a very important role at the diagnosis with the help of whole brain examination. For progressive retinal astrocytic hamartoma,systemic evaluation with CT and MRI can provide evidence for choosing appropriate thera- pies.

Objective To describe CT and MRI imaging findings of retinal hamartomas with tuberous sclerosis and evaluate their clinical value. Design Retrospective case series. Participants 7 patients of tuberous sclerosis complex (TSC) who have ocular lesions found with CT and MRI examination. Methods 7 patients with tuberous sclerosis were diagnosed by clinical data and head CT. The size, morphology, density and enhancing situation of the retinal lesions were observed with CT and MR.I, as while as with direct or indi-rect fundoscopy. Main Outcome Measures CT and MRI features of ocular lesions. Results 7 cases displayed intraeranial calcification and/or non-calcified tubercles, situating in subendyrna (7 cases, accounting for 100%) by head CT. Orbital CT and MRI showed 4 cases (57.1%) of flat retinal hamartomas 3 cases (42.9%) 9f retinal lobular and nodular hamartomas, 2 cases(28.6%) scattered calcification patches in hamartoma, and 2 cases (28.6%) of nanophthalmos. The lesions displayed unenhancement on contrast-enhanced MR images in 7 cases(100%) . There was 1 case (14.3%) of progressive retinal astrocytic hamartoma. Conclusion The examination of CT and MRI may find the bigger retinal hamartomas, which can play a very important role at the diagnosis with the help of whole brain examination. For progressive retinal nstrocytic hamartoma,systemic evaluation with CT and MRI can provide evidence for choosing appropriate thera-pies. (Ophthalmol CHN, 2009, 18: 257-260)

BACKGROUND: Bone marrow mesenchymal stem cells (BMSCs) have a remarkable differentiation potential and superiority as a type of seed cells,but their application is limited in the presence of certain diseases,such as aplastic anemia and myelogenous neoplasm.The present studies have found that seed cells called muscle-derived stem cells (MDSCs) have brought more and more attention,because of their capability of stir-renewal and multi-diffcrentiation like B MSCs.OBJECTIVE: To explore the biological characterization of the muscle-derived stem cells (MDSCs) from rabbits,and analyze the phenotype.DESIGN,TIME AND SETTING: Cell in vitro observation experiment was performed at the Medical Research Center of Second Affiliated Hospital of Sun Yat-sen University from August 2005 to March 2006.MATERIALS: A New Zealand rabbit (1.5 months old,clean grade) was enrolled for the preparation of Muscle-derived stem cells.Growth medium was DMED-LG added with 10% fetal bovine serum and 10% horse serum and fusion medium was DMEM-LG added with 2% fetal bovine serum.METHODS: The muscle mass was removed from the anesthetized rabbit to isolate MDSCs.These cells were dissociated using three enzymes (collagenase XI,dispase and trypsin) respectively.Sediment was resuspended.Then preplate technique was used.The muscle cell extract was plated on a collagen-coated culture flask with growth medium.The flask was called PP1.PPI was kept overnight in a 37 ℃ incubator containing 5% CO2,After that,the suspension was transferred to another collagen-coated culture flask,which was called PP2.PP3,PP4,PP5 and PP6 were constructed later following the same procedures.The cells adhered in PP6 were collected,plated in 6-well plates,and divided into 2 groups.Growth medium was used in one group,in which the cells were kept growing at a degree of confluence beyond 50%,and fusion medium was used in the other one,in which the cells were passaged with a degree up to 30%.MAIN OUTCOME MEASURES: The cells from PP1 to PP6 were collected,and the characterization was identified preliminary by Flow cytomctry,Immunocytochemistry and Western Blotting.The fusion of cells in PP6 was detected at different confluence degrees and concentration of medium.RESULTS: The cells in PP6 showed ＞ 80% desmin+,＞ 70% Bcl-2+,＞ 95% CD45,which indicated that MDSCs were in a high concentration.The expressions of α-SMA in the cells were decreasing with the Preplate technique used and the cells in PP6 almost had no α -SMA expression.When passaged at a high confluence (＞ 50%) or cultured with low concentrations of serum (2% serum),the cells in PP6 had a strong tendency of fusing into myotubes or cell chains and were skeletal myosin+.CONCLUSION: MDSCs,which are capable of multi-differentiation under a high fusion or low serum conditions,express dcsmin and Bcl-2 highly,but extreruelv little CD45 and no α -SMA.

Objective To measure the leakage rate in the process of expansion in vivo and in normal saline and the over-expansion property of the expander.Methods We chose 17 cases that were treated with the skin expansion.We recorded total injected saline volume intentionally in these cases before the second surgery,and recorded the remainder of the volume of saline postoperatively.We injected normal saline into 8 expanders,respectively,exceeding 50％ of the volume-rating;and subsequently put these expanders into plastic bucket filled with saline.30 days after,we measured the remaining volume of the normal saline.We injected 100 ml normal saline into 4 expanders,respectively,of which nominal volume was 100 ml,and then left these expanders in saline and measured the remainder volume of the saline 30 days later.In the second time,we injected 150 ml and repeated the abovementioned process.It was repeated 7 times until the injection volume reached 400 ml.We processed the data and depicted a curve of effective expansion.Results The results showed that the leakage rate reached (29.0+12.5) ％ in vivo.Experiments in vitro confirmed that 85.0％ (8.0/9.4) of the saline leaked through the injection port and 14.8％ (1.4/9.4) leaked through the membrane of the expander.In addition,over-expansion performance index test confirmed that the over-expansion property of an expander was about twice the nominal volume.Conclusions The expander is not completely sealed structure.Normal saline can leak through the injection part and the membrane of the expander.The over-expansion property of an expander is limited.When the volume injected into the expander exceeds a certain value,the effective expansion performance is not increased with it.

Objective To establish a stable and controllable model of acute regional cerebral ischemia in rats, and to evaluate it by CT perfusion imaging and histological study. Methods Twenty eight male Wistar rats were randomly divided into 4 groups, and there were 7 rats in each group. The sham operation rats were defined as the first group, rats suffered from cerebral ischemia for 15 minutes were classified as the second group, rats suffered from cerebral ischemia for 30 minutes and then reperfusion for 1 hour as the third group, and rats suffered from hypo perfusion for 6 hours as the fourth group. Cerebral ischemia or hypo perfusion were induced by inserting a nylon thread of different diameter into right middle cerebral artery (MCA) of rats under the monitoring of regional cerebral blood flow (rCBF) by the Laser Doppler Blood Perfusion Monitor (BPM). rCBF was also examined by dynamic CT perfusion imaging. At the end of the observation time, rats were decapitated, and three rats of each group were performed 2,3,5 triphenyltetrazolium chloride (TTC) staining and four rats were performed histological study. Results In the second group, rCBF was controlled within 5% to 22% under the monitoring by BMP and CT perfusion imaging showed the decreased rCBF in 7 rats, but TTC staining showed red appearance indicating no infarction focus formed. Electronic microscopic study revealed astrocytic swelling and a few of neuronal degeneration. In the third group, rCBF was controlled within 4% to 23% under the monitoring by BMP. There were more severe astrocytic swelling and a lot of neuronal degeneration. The abnormal areas in CT perfusion images were the same as TTC staining. In the fourth group, in accordance with less decrease ment of rCBF (from 38% to 55%) in 7 rats, there were obvious astrocytic swelling and subtle neuronal degeneration. TTC stain did not show ischemia area. All these abnormal changes were not observed in the sham operation rats. Conclusion The controllable acute regional cerebral ischemic model in rats is very stable and repeatable. It can be simulated into the ischemic state of different perfusion level. This model is suitable for the research of acute cerebral infarction and regional cerebral ischemia. The facts that parallel changes existed among BMP measurement, CT perfusion imaging, and brain histology indicated that CT perfusion imaging is accurate and sensitive in evaluating acute regional ischemia.

Objective To investigate the CT perfusion imaging and the pathological features on the disturbance of regional cerebral microcirculation in a pre-infarction period, and to evaluate the relationship between the astrocytes and regional cerebral microcirculation. Methods Dynamic CT perfusion imaging of the models with regional cerebral hypoperfusion and astrocytic swelling in rats was performed to assess the presence or absence of the disturbance of regional cerebral microcirculation. Then, the histopathologic examination was made for both models, respectively. The ratios of side-to-side were measured at hypoperfusion areas in the models of regional cerebral ischemia. Results Regional hypoperfusion was revealed by regional cerebral blood flow (rCBF) and mean transit time (MTT) maps in the group of hypoperfusion for 6 hours. Regional cerebral blood volume (rCBV) and time-to-peak (TTP) maps were normal in that group. The ratios of rCBF, rCBV, MTT and TTP were 0 39-0 55, 0 92-1 00, 1 20-1 50 and 1 00-1 00 respectively. Astrocytic swelling pressing the capillary wall was obvious and subtle neuronal reversible degeneration was occasionally found. TTC stain was normal. In the tACPD group of astrocytic swelling, the abnormal hemodynamic regions on rCBF and MTT maps were found. The rCBV maps of 3 rats in the tACPD group showed the area of reduced rCBV. In 2 rats of tACPD group, the areas of delayed TTP were also found. The ratios of rCBF, rCBV, MTT and TTP were 0 25-0 44, 0 70-1 01, 1 20-2 00 and 1 02-1 45 respectively. TTC stain was negative. Electron microscope study revealed remarkable swelling of astrocytes, especially endfoot processes of astrocytes around capillaries. The abnormal hemodynamic region on rCBF and MTT maps matched with abnormal extent on histopathologic examination. The rCBV and TTP maps appeared normal. Conclusion The astrocytes can react in a way faster than the neurons in the pre-infarction period, viz. astrocytic swelling. The swelling of astrocytic foot, which pressed capillary vessel, induced the disturbance of regional cerebral microcirculation, and then aggravated hypoxic ischemic state in regional brain parenchyma. Perfusion CT and its parameters' analysis may play an increasing role to delineate the reversible hypoperfusion areas in pre-infarction period. Analyzing the relationship of rCBF and rCBV is very helpful to know the status of the capillary vessels in regional cerebral hypoperfusion area.

Objective To investigate the effect of tissue expansion in facial congenital giant nevus.Methods From October 2014 to October 2016,7 cases of facial congenital giant nevus patients were treated with expanded skin flaps,including single expansion and secondary expansion.Partial excision and skin tissue expansion were used to drastically remove giant pigmented nevi on body or extremities of infants.There were some points for attention during the surgery:the size and location of the partial excision and expander should be designed reasonably;no tumor-manipulation and non-tension principle should be taken great notice,and expanders should be linked up with one another when several expanders were used at the same time,so as to reduce the possibility of forming the envelop,which was favorable for the second surgery of transfer of a skin flap.Results All cases of giant pigmented nevi excision were on the face,which were completely removed from the patients.The areas of the nevi were from 7 cm × 5 cm to 15 cm × 13 cm.All patients were followed up for 3-12 months (mean 6 months).All flaps survived well.Expander exposure was happened in 2 cases with no bad results.One case of scar received late repair due to surgical scars and all got satisfactory results.Conclusions Tissue expansion is an ideal method in the treatment of facial congenital giant nevus.

Objective To evaluate the clinical effect of clitoroplasty with preservation of the glans clitoris and the dorsal neurovascular pedicle in patients with clitoral hypertrophy. Methods From July 2003 to June 2009, cunnus feminization operations with preservation of the glans clitoris and the dorsal neurovascular pedicle and labioplasty were performed on 8 patients with female pseudohermaphroditism. Results All 8 cases were primary healing. The shaping glans of clitoris was completely viable with satisfactory size, location, contour and touching sensitivity, and the cunnuses presented the appearances of female external genital organs. Conclusions Clitoroplasty with preservation of the glans clitoris and the dorsal neurovascular can improve the appearance of clitoris and labia, preserving the functions of sensation and erection, reconstruting a new clitoris which is aesthetically appealing and functional, and it is suitable for various kinds of cunnus feminization operations.

Objective To investigate the correlation of the type of hypospadias and external genital system malformations. Methods From Jan 2000 to Oct 2009, the data of 632 patients diagnosed with hypospadias was analyzed retrospectively. The proportion of all types of hypospadias and the frequency of external genital system malformations were statistically analyzed. Results Among all cases, 12.6% exhibited mild hypospadias, 22. 8% moderate, 43. 2% severe and 21.4% had extremely severe hypospadias. One hundred and eighty-four cases with external genital system malformations were classified into penoscrotal transposition, cryptorchidism, hydrocele of tunica vaginalis,concealed penis and pseudovagina. The probability was about 24.8% (157 cases) of 632 patients with hypospadias. There was significant difference and a positive correlation among the type of hypospadias with total malformations, penoscrotal transposition, cryptorchidism. Conclusions In this patient cohort, moderate and severe hypospadias accounted for the majority of hypospadias. Penoscrotal transposition was the most frequent external genital system malformation in hypospadias, followed by cryptorchidism and hydrocele of tunics vaginalis. More severe hypospadias is accompanied with a higher probability of the external genital system malformations, penoscrotal transposition and cryptorchidism.