BACKGROUND:Epidermal stem cells as special stem cells of the skin not only plays an important role in maintaining the metabolism of skin, but also is closely related to wound repair, which are the basis for the occurrence and repair of skin and its appendages. Now, epidermal stem cells have been paid great attention on the research of gene therapy and celltherapy with its specific biological advantages. OBJECTIVE:To summarize the research status on features and clinical application of epidermal stem cells. METHODS:A computer-based online retrieval of CNKI, PubMed database and Google scholar was performed for searching papers about clinical application of epidermal stem cells using the keywords of“epidermal stem cells, stem cells division, stem cells culture, clinical application”in Chinese and English. Older theoretical perspectives and repetitive research were excluded. Finally, only 41 articles were included in result analysis. RESULTS AND CONCLUSION:Epidermal stem cells have the great potential of proliferation and multi-directional differentiation, and have important significances for large-area skin defects (burn and trauma), skin tissue engineering, and gene therapy. There are stil many problems that need to be solved, such as how to screen surface markers special for epidermal stem cells and how to induce skin differentiation of epidermal stem cells.

Phospho-histone H2AX(γH2AX) has been widely used in vitro genotoxicity evaluation of ionizing radiation, carcinogenic substances and cigarette smoke as an important biomarker of DNA double stranded breaks ( DSBs) . The study developed an enzyme-linked immunesorbent assay for detection of the content ofγH2AX in cells to evaluate the genotoxicity of cigarette smoke. The study exposed CHO cells with cigarette smoke total particulate matter ( TPM) and cigarette smoke condensate ( CSC) of different dose, dose-effect relationship between smoke exposure and DNA damage and the poisonous difference of cigarette smoke components has been investigated by detecting the content change ofγH2 AX in cells under different exposure time and dose. In addition, reactive oxygen species ( ROS) in cells were also detected to study the mechanism of cigarette smoke exposure induced DSBs. The experiment result showed that the required time for the level ofγH2AX in cells grew to the peak prolonged with increased exposure dose. Once the level of γH2AX in cells grew to the peak value, then it decreased slowly; the level of γH2AX in cells rised with increasing dose of cigarette smoke;The effect of TPM on the content change of γH2AX was more than CSC; Moreover, smoke exposure could induce concentration increase of ROS in cells, and a good correlation of content change of ROS and γH2AX in cells were found, free radicals in cigarette smoke may be one major cause of DSBs.

Objective To observe the changes of urine microalbumin (mAlb), renal function and intima-media thickness(IMT) of the carotid artery in prehypertensive patients and investigate whether there are related target organ damage. Methods From August 2009 to May 2010,one hundred and eighty patients were recruited into the study and divided into 3 groups according to the 2005 revised edition of guideline for prevention and treatment of hypertension in China: Sixty normotensive subjects ( NT group,41 males, 19 females,mean age [54. 6 ± 12. 3] years old) ;Sixty prehypertensive patients( PH group,32 males,28 females,mean age [57.0 ± 12.7] years old) and 60 hypertensive patients ( EH group, 28 males, 32 females, mean age [65.0 ±12. 1] years old). Urine mAlb, serum creatinine(Cr) and IMT of the carotid artery were measured and compared among the three groups. The relationships between prehypertension and urine mAlb,serum Cr, IMT of the carotid artery were analyzed. Results In the NT group, PH group and EH group, the urine mAlb concentrations were ( 15.3 ± 7.5 ) mg/L, ( 24. 6 ± 10. 7 ) mg/L and ( 37.3 ± 20. 4) mg/L respectively ;serum Cr were ( 68.0 ± 16. 5 )μmol/L, (81.9 ± 14.9)μmol/L and (95.8 ± 22.5)μmol/L respectively; IMT of the carotid artery were ( 1.46 ± 0. 67 ) mm, ( 1.79 ± 0. 74 ) mm and( 2. 34 ± 0. 78 ) mm respectively. Urine mAlb, serum Cr and IMT of the carotid artery were significantly higher in the PH group and EH group when compared to NT group ( P ＜0. 05 or 0. 01 ); and in the EH group these indices were also significantly higher than those in the PH group( P ＜0. 01 ). Multiple linear regression analysis showed that after adjusted age, body mass index (BMI), blood pressure( BP), serum lipid and serum glucose, in the PH group,the standard partial regression coefficients of correlation between urine mAlb and systolic blood pressure (SBP), diastolic blood pressure(DBP) and serum glucose were 0. 279,0. 259 and 0. 360 respectively ( P = 0. 012, 0. 043 and ＜ 0. 001 ); the standard partial regression coefficients of correlation between serum Cr and SBP, DBP and serum glucose were 0. 317,0. 257 and 0. 377 respectively ( P = 0. 006,0. 049 and ＜ 0. 001 ). The standard partial regression coefficients of correlation between IMT of the carotid artery and age, SBP, DBP, total cholesterol and serum glucose were 0. 381,0. 375,0. 263,0. 265 and 0. 372 respectively( P ＜ 0. 001, ＜ 0. 001, = 0. 033,0. 021 and ＜ 0. 001 ). In the EH group, the standard partial regression coefficients of correlation between urine mAlb and SBP, DBP and serum glucose were 0. 378,0. 258 and 0. 283 respectively( P ＜ 0. 001, = 0. 046, and 0. 009); the standard partial regression coefficients of correlation between serum Cr and SBP, DBP and serum glucose were 0. 294,0. 261 and 0. 464respectively (P =0. 008,0. 042 and ＜0. 001 ) ;the standard partial regression coefficients of correlation between IMT of the carotid artery and age, SBP, high density lipoprotein cholesterol and serum glucose were 0. 262,0. 264, -0. 374 and 0. 306 respectively ( P = 0. 035,0. 023, ＜ 0. 001 and 0. 007 ). We found that both urine mAlb and serum Cr were significantly associated with BP and serum glucose; IMT of the carotid artery was significantly associated with age, BP, serum lipid and serum glucose. Conclusion Urine mAlb, serum Cr andIMT of the carotid artery increased in prehypertensive patients, and these indices were significantly associatedwith the level of the BP. These data indicated there were related target organ damage occurred in prehypertensive patients,the BP level was the risk factor that increased urine mAlb,serum Cr and IMT of the carotid artery.

Since γH2 AX was firstly found in 1998 , it has been one of the most important scientific topics and research tools in the related scientific fields. At present, a series of advanced testing methods and analytical technologies have been developed, which exhibited a quite attractive application prospect in the area of life science and medical science. This paper reviewed the latest progress about γH2AX in terms of molecular mechanism of phosphorylation/dephosphorylation, development of testing technologies, and the related applications.

Stable isotope coded derivatization (ICD) is an isotope labeling technique for specific functional groups of the target analytes through chemical derivatization.ICD combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) enables systematically analyzing the biomolecules with the same labeling reaction characteristic.ICD technique can effectively solve the limited sensitivity in complex bio-matrices analysis and unavailability of isotope internal standards in quantitative analysis.In recent years, ICD technique has been widely used in metabolomics research field.Based on this background, the ICD technique and the design of ICD reagents are briefly described in this review.The recent advances in ICD reagents for carboxyl, amino, carbonyl, thiol and hydroxyl groups and their applications in the analysis of small molecule metabolites in bio-matrices with LC-MS/MS are reviewed.

BACKGROUND: Based on our previous researches in mechanism studies and clinical applications of human hair keratin (HHK), a new concept "in vivol in situ tissue engineering" has been proposed. Under the guidance of this theory, a scaffold of HHK-collagan sponge (inner layer) combined with poly (2-hydroxyethyl methacrylate) (PHEMA) (outer layer as a drug delivery carrier) would be developed to investigate its feasibility to be as a dermal dressing. OBJECTIVE: To develop a scaffold composed of HHK-collagan sponge (inner layer) combined with PHEMA film containing polydatin(PD)(outer layer as a drug delivery carrier) and to evaluate the therapeutic efficacy of the HHK-collagen sponge-PHEMA/PD complex on burn wound healing. DESIGN, TIME AND SETTING: A randomized controlled animal experiment was performed at the Department of Histology and Embryology, Southern Medical University between March and December 2005. MATERIALS: Burn was induced in 15 male Sprague-Dawiey (SD) rats, Rat models of burn were evenly randomized to 3 groups: experimental, positive control, and negative control. METHODS: ①HHK-collagen sponge was prepared through combination of a HHK meshwork (1mm × 1 mm in size for each grid) made up of three components (determined according to biochemical procedures of various degrees, i.e., light, medial, and severe) at a ratio of 4:3:3 with primary collagen sponge extracted from bovine tendons in a mould. Sponge film (used as inner layer dressing) was made by vacuum freeze-drying. ② PHEMA was prepared by polymerization. Than PD was added to prepare PHEMNPD film (used as outer layer dressing).③ Degree Ⅱ burn wound models were established in SD rats by scalding, Superficial necrotic tissue was removed from burn wounds at postnatal 3 days and leave the denatured dermis remained. The wounds were either covered with human HHK-collagen- PHEMNPD complex in the experimental group, or with glutaraldehyde-treated porcine skin in the positive control group, and sterile absorbent gauze was used in the negative control group. MAIN OUTCOME MEASURES: ① Complete epithelization was taken as the standards, and at postoperative 7, 14, and 21 days, wound healing was respectively calculated. ② At postoperative 1, 2, 4, 6, and 8 weeks, the whole wound surface and its peripheral tissue were dissected for observing granulation tissue growing under an optical microscope and detecting the collagen fiber and elastic fiber in the newly formed tissue by immunohistochemical staining. RESULTS: ① Gross observation results revealed that in the experimental group, the volume of the diffusate under the ideal moisture was less compared with the positive control group; the healing time was slightly shorter in both the experimental group and the positive control group than in the negative control group (P= 0.000); At postoperative 7, 14, and 21 days, the healing rate was higher in the experimental and positive control groups than in the negative control group (P=0.000), in addition, the experimental group exhibited higher healing rate than the positive control group at postoperative 14 days ( P ＜ 0.05). ②Optical microscope results showed that at postoperative 2 weeks, a small quantity of collagen fibers were found in the wound granulation tissue in all 3 groups, in particular in the experimental group. Immunohistochemical staining results regarding collagen protein and elastin revealed that at postoperative 2 weeks, both the fine strip-like type Ⅰ collagen fibers and a few silk-like elastic fibers were stained yellowish-brown in the dermal matrix in the experimental group, which were weakly positive in the positive control group, while there was no elastin detectable in the negative control group; at postoperative 8 weeks, burn wounds in all the 3 groups werefully recovered. Remodeling of collagen fibers was more obvious in the experimental and positive control groups than in thenegative control group, while the tendency to scar formation with derangement of epithelial cells and collagen fibers in dermis was more prominent in the negative control group than in the remaining two groups.CONCLUSION: HHK-collagen sponge-PHEMA/PD complex may be a new burn dressing via in vivo construction of tissueengineered epidermis, in which PHEMA may be a feasible drug-delivery carrier.

A liquid chromatography-tandem mass spectrometry ( LC-MSMS ) method has been developed for the simultaneous determination of N3-methyladenine ( N3-MeA ) and N3-ethyladenine ( N3-EtA ) in calf thymus DNA. The DNA samples has been purified and enriched by cation exchange cartridge ( Waters Oasis MCX) . d3-N3-MeA and d5-N3-EtA were used as isotope internal standard. The DNA samples were injected with autosampler. The injected volume was 3 μL and analysis time was 13 min. The sample separation was carried out on hydrophilic interaction chromatograph ( Waters XBridge HILIC ) with 10 mmol/L ammonium formate-acetonitrile (5:92, V/V, pH=4. 0) as mobile phase. The flow rate was set at 250 μL/min. Mass spectrometry was performed by electrospray ionization ( ESI ) with multi-reactions monitoring ( MRM ) . The optimized operation conditions of MS were as follows: nebulizer gas 369 Pa; curtain gas 185 Pa, turbo ionspray temperature 400 ℃, ionspray voltage 5500 V, dwell time 40 ms. The limits of detection were 0. 043 and 0. 007 μg/L for N3-MeA and N3-EtA, respectively. The recoveries were between 87. 8% and 103. 0%for N3-MeA and N3-EtA. This method was successfully applied to the determination of N3-MeA and N3-EtA in calf thymus DNA by cigarette smoke condensate ( CSC) exposure. This method is appropriate for routine analysis and accurate quantification of N3-MeA and N3-EtA by CSC exposure.

Objective To explore the protective effects of a new military functional food NB-5 on psychological stress-induced oxidative stress .Methods Rat whiskers were completely removed to induce the oxidative stress , and the concen-trations of MDA and protein carbonyl in various organs were detected to study the damage to membrane lipid and protein . Rats were fed with NB-5 for 4 weeks, and the oxidative stress was induced by whisker cutting .Biochemical marks men-tioned above were detected to explore the protective effects of NB-5.Results and Conclusion Lipid and protein peroxida-tion occurred in the brain , heart, liver, spleen and kidney after whisker removal due to emotional stress , while the catalase ( CAT) activity decreased significantly in these organs except the spleen .In this experiment model , NB-5 showed a good free radical scavenging activity to reduce the lipid and protein peroxidation among whisker -cutting rats fed with NB-5 in ad-vance.So NB-5 can serve as a good food for soldiers in case of emergency incidents .

Objective This paper selects indicators,such as SCI journal publication fee,impact factors,annual Web of Science Documents,volume of publications in China,articles cited and so on,to conduct the feasibility analysis of using publication fee /impact factor (BI) as evaluation index of SCI journals.Methods Information from Web of Science,InCites,Journal Citation Reports database and the real-time data of 2013-2017 years SCI publication fees in Central South University,the third Xiangya Hospital were collected,SPSS and EXCEL was used to conduct Correlation and Basic analysis.Results In 2013-2017,a total number of 31 kinds of SCI journals were included in sample size,the SCI journal impact factor was positively correlated with the publication fee.BI was negative correlated with IF,The publication fee was not related to annual Web of Science Documents,volume of publications in Mainland China and Cites/Paper.Conclusions The SCI journal publication fee/impact factor (BI) can be used as a macro evaluation index for SCI journals.The BI values also can provide reference and reference of decision support and journal selection for scientific research personnel and scientific research administrators.

Objective:This study conducted a statistical analysis of the 2010 to 2019 Chinese Medical Science and Technology Award to understand its current situation and research hotspots, to provide references for medical science and technology investigators and administrators.Methods:Through the official website of the Chinese Medical Association, the 2010 to 2019 Chinese Medical Science and Technology Award data was collected. Information includes gender of the awardees, award level, geographical distribution, discipline distribution, and completion unit of the first person was analyzed. Network metrology, social network analysis and word cloud graph analysis are used to analyze the " development status" , " cooperative relationship" and " research hotspots" of medical research in China.Results:The total number of winning projects was 857. Among them, the number of first, second, and third prizes were 76, 249 and 475. Beijing is the area with the largest number of winners (277), followed by Shanghai (167) and Jiangsu (92). Among the winning projects, the top 3 subject were oncology, cardiology, orthopaedics, general surgery with percentages accounted by 9.78%, 7.94%, 6.21%.Conclusions:The geographical distribution of winning projects presented a regional concentration trend. The disciplines of award-winning projects have been diversified, especially in oncology. The gender ratio of principal investigators is uneven, most were male. Future research should pay more attention to multidisciplinary, cross-regional facilitation, and promote the coordinated development of holistic medicine.