Epidermal stem cells (ESCs) play a critical role in homeostasis and wound repair of skin tissue. Since ESCs are rare (fewer than 10% in total basal cells population) and lack specific markers,it is difficult to isolate and identify them from keratinocytes. Currently ,isolation of ESCs was achieved mainly by fast adhesion of ESCs to extracelluar matrix or flow cytometry. Several specific markers have been found in recent years for the identification of ESCs.

Objective To compare HASTE-MRCP single-slice acquisition technique with ordinary MR cholangiopancreatography (OMRCP) and to assess the clinical application value of HASTE-MRCP single-slice acquisition technique.Methods 48 cases with biliary obstructive diseases and 30 cases without obstructive jaundice were studied with a 3. 0T super conductive unit(Magnetom Trio;Siemens,Germany) that used a body coil. Two acquisition techniques of MRCP were used for all patients . The accuracy of the two kinds of technique were compared. Results OMRCP , single-slice HASTE-MRCP had the same sensitivity and specificity in showing the site and feature of the diseases , the proximal dilated biliarys and distant normal cholangiopancreatic ducts .The diameter of dilated bile ducts at the same level was compared and no significant difference in them. Single-slice HASTE-MRCP had a high spatial resolution ,and shot aquisition time ,but more vessel artifact. OMRCP had high density resoultion ,but more motion artifacts.Conclusion The single-slice acquisition of HASTE-MRCP is an excellent technique in the diagnosis of biliary tract diseases.

Objective To study the capability in detection and qualitative analysis of carotid atherosclerotic plaque with 3.0T MR scanner.Methods Bilateral carotid arteriae in thirty-two patients with arterosclerosis which detected by Doppler ultrasound were examined with a 3.0T MR scanner.The pulse sequences included 3D time of flight,FLASH-3D,TSE-DIR T_1WI,TSE-DIR PDWI-FS,DIR TSE-T_2WI-FS and TSE-T_2WI.According to AHA modified criteria of atherosclerosis typing,the signal characteristics of plaques were analysed.Results Carotid plaques were homogeneous signal intensity on all sequences in 30/49,heterogeneous signal intensity on at least one sequence in 15/49,among them,7 with lipid core,3/49 plaques contained calcification ,2/49 appeared as thrombosis and resulting in vessel occulusion,28/49 plaques presented the character of thick fibrous cap,13/49 plaques showed character of thin fibrous cap,the surfaces of 5/49 plaques were rough.Conclusion High resolution multiple sequences imaging with 3.0T MR scanner can be used for detection and qualitative analysis of the carotid atherosclerotic plaque in a certain degree.

Objective To evaluate sound velocity tissue quantification ( SVQ ) for the quantitative assessment of liver fibrosis stage in chronic hepatitis B ,and to evaluate the correlation between diagnostic performance of sound velocity tissue quantification and blood parameters . Methods From the May of 2013 to May of 2014 ,collect ninety‐nine patients with chronic hepatitis B who was diagnosed by clinic and / or liver biopsy as experiment group ,and thirty healthy volunteers as control group at the same time . The experiment group and control group were evaluated with to measurement the zone speed index ( ZSI) ,and blood cell count . The AST/PLT ratio index ( APRI) was calculated according the following formula , APRI=AST(ULN)/PLT(109/L) . The liver biopsy was performed in the same day with SVQ and all blood parameters .ZSI and APRI were compared by correlation with liver fibrosis stage in chronic hepatitis B . Referring to the histologic fibrosis stage on liver biopsy ,all the ZSI and the APRI value were assessed by using ROC curve analysis . The corresponding cut‐off value ,sensitivity and specificity were also calculated andcompared.Results 1)ThemeanvaluesofAPRIwere(15.9±5.7)m/sforpatientswithS0,(28.1± 2 .8)m/s for patients with S1 ,(35 .8 ± 1 .2)m/s for patients with S2 ,(42 .6 ± 0 .8)m/s for patients with S3 , and (46 .3 ± 1 .3)m/s for patients with S4 .2)Accordingly ,the areas under the ROC curve for ZSI and APRI were 0 .875 and 0 .762 for S≥S1 ,0 .832 and 0 .597 for S≥S2 ,0 .913 and 0 .675 for S≥S3 ,0 .891 and 0 .709 for S≥S4 ,respectively . Conclusions The ZSI and APRI all could be used to evaluate the stage of liver fibrosis ,but the ZSI index is superior to APRI in assessing the stage of liver fibrosis . SVQ could provide object and accurate image ,the quantitative analysis of tissue could timely and accurately evaluate the severity of liver fibrosis .

One case of lipoma was reported in retropharyngeal space. Oropharyngeal CT showed: tumor's size was 59.2 mm x 28.4 mm, the boundary was clear, and the surrounding tissue was pressed obviously. Retropharyngeal space lies between posterior wall of the pharynx and prevertebral space, and contains fat and lymphoid tissue. Retropharyngeal space tumor often showed no clinical symptoms early. Tumor could show airway obstruction when growing up. Surgical operation is the only treatment method.
Aged ; Female ; Humans ; Lipoma ; pathology ; Pharyngeal Neoplasms ; pathology

RNA interference (RNAi) is a newly developed technology. It is the different levels of gene silencing induced by specific degradation of targeted genes in vivo, and both exogenous and endogenous double-stranded RNAs could induce the specific degradation. RNAi has been applied in tumor therapy, viral infection, hepatitis B and many other diseases. siRNA is the effector molecule which induces the RNAi in vivo. But naked siRNA is easily degradated by RNases in vivo, and the half-life is short. Meanwhile, the transfection efficiency of the naked siRNA is comparatively low. So the naked siRNA needs the help of vectors to penetrate the cell membrane and take action. Viral vectors have the potential immunogenicity and mutagenicity in gene therapy. Therefore, non-viral vectors are drawing more and more attention. The latest development of the non-viral vectors is summarized in this review.

Diterpenes, an important class of natural compounds, are widely distributed in nature. As the valuable diterpenoids continue to be found, diterpene synthase in the course of diterpene synthesis get as much attention as possible. The multiformity of end-product-diterpenoids were also due to the diversity of diterpene synthase. This paper focuses on the advances in recent biosynthesis pathway of diterpene and types, cloning, catalytic mechanism, synthetic biology application.

BACKGROUND: Lumbar spondylolysis is the common cause of teenagers' low back pain. It should apply internal fixation if conservative treatment is invalid. There are a variety of surgeries, which aims to alleviate pain and bony fusion of pars defect.OBJECTIVE: To observe clinical outcome of bone graft of pars defect plus temporary single segmental pedicle screw rod fixation for adolescent lumbar spondylolysis.METHODS: A total of 32 adolescent patients of lumbar spondylolysis were treated by bone graft of pars defect plus temporary single segmental pedicle screw rod fixation. All the patients had bilateral spondylolysis. 20 patients had no lumbar spondylolisthesis, while the others had I° spondylolisthesis. All the patients received lumbar radiograph, CT and MRI. Visual analogue scale and Oswestry disability index were utilized to evaluate pain improvement before and after operation. MacNab was used to assess efficacy. Bone graft healing at isthmus was observed with lumbar CT after fixation. The internal fixation was removed after bone fusion, then the motion of the fixed segment and the degeneration of adjacent intervertebral disc occurred were recorded.RESULTS AND CONCLUSION: (1) Completed bone fusion of pars defect was achieved in all the patients. The average period of bone union was 7.4 months. (2) The visual analogue scale and Oswestry disability index scores were significantly improved after surgery in all patients (P < 0.05). (3) The fixed segment reserved the motion after internal fixation removal. The signal of adjacent intervertebral disc of fixed segment had no changes compared to preoperative MRI. (4) Bone graft to repair isthmus defect plus temporary single segmental screw rod fixation for adolescent lumbar spondylolysis is very effective, the bone fusion is completed, and temporary fixation may effectively alleviate the degeneration of adjacent disc.

Objective To investigate the effect of inversion time (TI) on flow-sensitive alternating inversion recovery (FAIR) perfusion imaging of spinal bone marrow (SBM),and evaluate the reproducibility of blood flow (BF) measurements using this technique.Methods Twenty four healthy volunteers without lumbar and other disease with clinical and MR studies were prospectively included.The first 14 healthy volunteers were included to study the effect of TI on ASL perfusion imaging of SBM to get the optimized TI,the remaining 10 volunteers were included to investigate the reproducibility of the SBM arterial spin labeling (ASL) scan protocol.The optimized TI of FAIR spinal bone marrow perfusion experiment was carried out on 14 healthy volunteers on 3.0 T magnet,two adjacent vertebral bodies were orderly selected from each volunteer to measure the △M and the SNR of FAIR perfusion MRI with 5 different TIs (800,1 000,1 200,1 400,1 600 ms),and the vertebral bodies selected order were determined by the order of the subjects enrolled.In addition,FAIR perfusion spinal vertebral BF measurements were repeated in last l0 healthy subjects on L4 or L5 by reposition immediately,paired t test and reproducibility statistics (included within-patient standard deviation (wSD) and within-patient coefficient of variation (WCV)) were used to analyze the test-retest experiment reproducibility.Result TI optimization experiments total included 28 vertebral bodies,when TI (ms) was chose as 800,1 000,1 200,1 400,1 600,ms respectively,the mean △M of spinal bone marrow were 20.8±9.0,29.0± 10.9,36.4± 12.5,26.2± 10.2 and 23.8± 11.5,and the mean SNR were 2.0± 1.0,2.3±0.8,2.4± 1.0,2.3±0.8 and 2.0±0.7.With TI increasing,AM and SNR increased first and then decrcascd,the maximum values of both were achieved when the TI near 1 200 ms.Test-retestexperimcnt were carried on 10 vertebral bodies eventually,and two measurements of spinal vertebral BF perfusion before and after were (108.9±4.6)and (109.2 ±4.6)ml · 100g-1· min 1,respectively,and no significant difference was found (t=-0.157,P=0.879),wCV of the measurements was 3.28％ (3.57/109.06).Conclusion The optimal TI was 1 200 ms for spinal bone marrow ASL perfusion image,at which the maximum AM,higher SNR,and good reproducibility for the FAIR spinal bone marrow perfusion imaging can be achieved.

Objective To analyze the treatment results of primary nasopharyngeal carcinoma(NPC)treated by four different external beam radiation therapy(EBRT)techniques in Sun Yat-sen University Cancer Center in the beginning of the 21 st century.Methods The data of 1093 hospitalized primary NPC patients treated in Sun Yat-sen University Cancer Center between December 2001 and June 2003 were retrospectively analyzed.The stage distribution(by AJCC/UICC,2002)was 63,439,358 and 233 patients in Stage Ⅰ,Ⅱ,Ⅲ and Ⅳa+Ⅳb.Definitive radiotherapy was given to all patients and the median total dose was 70 Gy.Four different EBRT techniques were used:812 patients with fluoroscopy simulation conventional radiotherapy(CR),155 patients with CT simulation conventional radiotherapy(CT-sim CR),69 patients with three dimensional conformal radiotherapy(3DCRT)and 57 patients with intensity modulated radiotherapv(IMRT). Results The 5-year local failure-free rate(LFFR),nodal failure-free rate(NFFR),and distant metastasis-free rate(DMFR)were 86.8%,95.3%and 83.2%,respectively.The 5-year progressionfree survival(PFS)and overall survival(OS)were 66.9%and 77.9%,respectively.Different EBRT techniques influeneed the OS and the LFFR of patients,the 5-year OS and LFFR of group CR,CT-sim CR,3DCRT and IMRT were 75.9%,83.5%,87.2%,86.6% and 84.5%,96.4%,91.0%,91.7%,respectively(P=0.014 and 0.006).The morbidity and severity of xerostomia and trismus were sigficantly lower in group 3DCRT and IMRT than in group CR and CT-sim CR(P=0.000 and=0.023). Conclusion The CT simulation technique,3DCRT and IMRT can improve the OS,LFFR and life qualitv of patients with primary NPC.