The Effect of the Swimmer's Trunk Oscillation on Dolphin Kick Performance Using a Computational Method with Multi-Body Motion: A Case Study.

The effect of a specific Chinese swimmer's trunk oscillation on dolphin kick was investigated in order to optimize competitive swimming movement. Using a numerical simulation method based on multi-body motion, different swimmer's trunk oscillation during a dolphin kick was analyzed. The simulation was conducted using 3D incompressible Navier−Stokes equations and renormalization group k-ε turbulence model, combined with the Volume of Fluid method to capture the water surface. The simulation's results were evaluated by comparing them with experimental data and with previous studies. The net streamwise forces, mean swimming velocity, and joint moments were also investigated. There was a positive correlation between the mean swimming velocity and the amplitudes of the swimmer's trunk oscillation, where the Pearson correlation coefficient was 0.986 and the selected model was statistically significant (p < 0.05). In addition, as the mean swimming velocity increased from 1.42 m/s in Variant 1 to 2 m/s in Variant 5, the maximum positive moments of joints increased by about 24.7% for the ankles, 27.4% for the knees, −3.9% for the hips, and 5.8% for the upper waist, whereas the maximum negative moments of joints increased by about 64.5% for the ankles, 28.1% for the knees, 23.1% for the hips, and 10.1% for the upper waist. The relationship between the trunk oscillation and the vortices was also investigated. Therefore, it is recommended that swimmers should try to increase the amplitudes of trunk oscillation to increase their swimming velocity. In order to achieve this goal, swimmers should increase strength training for the ankles, knees, and upper waist during the upkick. Moreover, extra strength training is warranted for the ankles, knees, hips, and upper waist during the downkick.

Hydrodynamic Characteristics of Different Undulatory Underwater Swimming Positions Based on Multi-Body Motion Numerical Simulation Method.

The study of hydrodynamic characteristics of swimming is the main way to optimize the swimming movement. The relationship between position, water depth, and swimming performance of undulatory underwater swimming are one of the main concerns of scholars. Therefore, the aim of this study is to analyze the swimming performance of three different undulatory underwater swimming positions under various swimming depths using a numerical simulation method based on multi-body motion. The simulation was conducted using 3D incompressible Navier-Stokes equations using the RNG k-ε turbulence closure equations, and in combination with the VOF method thus that we could include the water surface in our calculations. Different swimming depths based on the distance from the shoulder joint center to the initial water surface were considered. The velocity of the shoulder joint center was captured with a swimming motion monitoring system (KiSwim) and compared with the calculated results. The study found that there was a significant difference in the hydrodynamic characteristics of the three undulatory underwater swimming positions (i.e., the dorsal, lateral, and frontal positions) when swimming near the water surface, and the difference decreased as the swimming depth increased. There was a negative correlation (R(dorsal) = -0.928, R(frontal) = -0.937, R(lateral) = -0.930) between the swimming velocities of the three undulatory underwater swimming positions and the water depth (water depth = 0.2-0.7 m) and that the lateral position had the greatest average velocity. Therefore, it is recommended that swimmers travel at least 0.5 m below the water surface in any undulatory underwater swimming position in order to avoid excessive drag forces. As the swimmer approaches the water surface, the lateral position is worth considering, which has better velocity and hydrodynamic advantage than the other two undulatory underwater swimming positions.

Review of fractional epidemic models.

The global impact of corona virus (COVID-19) has been profound, and the public health threat it represents is the most serious seen in a respiratory virus since the 1918 influenza A(H1N1) pandemic. In this paper, we have focused on reviewing the results of epidemiological modelling especially the fractional epidemic model and summarized different types of fractional epidemic models including fractional Susceptible-Infective-Recovered (SIR), Susceptible-Exposed-Infective-Recovered (SEIR), Susceptible-Exposed-Infective-Asymptomatic-Recovered (SEIAR) models and so on. Furthermore, we propose a general fractional SEIAR model in the case of single-term and multi-term fractional differential equations. A feasible and reliable parameter estimation method based on modified hybrid Nelder-Mead simplex search and particle swarm optimisation is also presented to fit the real data using fractional SEIAR model. The effective methods to solve the fractional epidemic models we introduced construct a simple and effective analytical technique that can be easily extended and applied to other fractional models, and can help guide the concerned bodies in preventing or controlling, even predicting the infectious disease outbreaks.

A fractional order epidemic model for the simulation of outbreaks of Ebola.

The Ebola outbreak in 2014 caused many infections and deaths. Some literature works have proposed some models to study Ebola virus, such as SIR, SIS, SEIR, etc. It is proved that the fractional order model can describe epidemic dynamics better than the integer order model. In this paper, we propose a fractional order Ebola system and analyze the nonnegative solution, the basic reproduction number R 0 , and the stabilities of equilibrium points for the system firstly. In many studies, the numerical solutions of some models cannot fit very well with the real data. Thus, to show the dynamics of the Ebola epidemic, the Gorenflo-Mainardi-Moretti-Paradisi scheme (GMMP) is taken to get the numerical solution of the SEIR fractional order Ebola system and the modified grid approximation method (MGAM) is used to acquire the parameters of the SEIR fractional order Ebola system. We consider that the GMMP method may lead to absurd numerical solutions, so its stability and convergence are given. Then, the new fractional orders, parameters, and the root-mean-square relative error g ( U ∗ ) = 0.4146 are obtained. With the new fractional orders and parameters, the numerical solution of the SEIR fractional order Ebola system is closer to the real data than those models in other literature works. Meanwhile, we find that most of the fractional order Ebola systems have the same order. Hence, the fractional order Ebola system with different orders using the Caputo derivatives is also studied. We also adopt the MGAM algorithm to obtain the new orders, parameters, and the root-mean-square relative error which is g ( U ∗ ) = 0.2744 . With the new parameters and orders, the fractional order Ebola systems with different orders fit very well with the real data.

Gliding locomotion of manta rays, killer whales and swordfish near the water surface.

The hydrodynamic performance of the locomotive near the water surface is impacted by its geometrical shape. For marine animals, their geometrical shape is naturally selective; thus, investigating gliding locomotion of marine animal under the water surface may be able to elucidate the influence of the geometrical shape. We investigate three marine animals with specific geometries: the killer whale is fusiform shaped; the manta ray is flat and broad-winged; and the swordfish is best streamlined. The numerical results are validated by the measured drag coefficients of the manta ray model in a towing tank. The friction drag of the three target models are very similar; the body shape affected form drag coefficient is order as swordfish < killer whale < manta ray; the induced wave breaking upon the body of the manta ray performs different to killer whale and swordfish. These bio-inspired observations provide a new and in-depth understanding of the shape effects on the hydrodynamic performances near the free surface.

Hydrodynamic analysis of human swimming based on VOF method.

A 3-D numerical model, based on the Navier-Strokes equations and the RNG k-ε turbulence closure, for studying hydrodynamic drag on a swimmer with wave-making resistance taken into account is established. The volume of fluid method is employed to capture the undulation of the free surface. The simulation strategy is evaluated by comparison of the computed results with experimental data. The computed results are in good agreement with data from mannequin towing experiments. The effects of the swimmer's head position and gliding depth on the drag force at different velocities are then investigated. It is found that keeping the head aligned with the body is the optimal posture in streamlined gliding. Also wave-making resistance is significant within 0.3 m depth from the free surface.

Numerical Investigation of Swimmer's Gliding Stage with 6-DOF Movement.

The purpose of this study is to analyze the motion status of swimmers during their gliding stage using a numerical simulation method. This simulation strategy is conducted by solving the 3D incompressible Navier-Stokes equations using the Realizable k-ε turbulence closure equations in combination with the Six Degrees of Freedom (6-DOF) method. The uneven mass distribution of a swimmer and the roughness of the surface of the body are taken into consideration. The hydrodynamic characteristics and movement characteristics of the swimmers at different launch speeds were analyzed. The calculated results suggest that an optimal instant for starting propulsive movement is when the velocity of the swimmer decreases by 1.75 m/s to 2.0 m/s from an initial horizontal velocity of 3.1 m/s to 3.5 m/s.

Hydrodynamic body shape analysis and their impact on swimming performance.

This study presents the hydrodynamic characteristics of different adult male swimmer's body shape using computational fluid dynamics method. This simulation strategy is carried out by CFD fluent code with solving the 3D incompressible Navier-Stokes equations using the RNG k-ε turbulence closure. The water free surface is captured by the volume of fluid (VOF) method. A set of full body models, which is based on the anthropometrical characteristics of the most common male swimmers, is created by Computer Aided Industrial Design (CAID) software, Rhinoceros. The analysis of CFD results revealed that swimmer's body shape has a noticeable effect on the hydrodynamics performances. This explains why male swimmer with an inverted triangle body shape has good hydrodynamic characteristics for competitive swimming.

Experimental study of comparing rhEGF with rhßFGF on improving the quality of wound healing.

The mechanism and biological effects of comparing recombinant human epidermal growth factor (rhEGF) with recombinant human basic fibroblast growth factor (rhßFGF) were evaluated on the model of incised wounds on ventral side of rabbit's ears in order to direct their medication in clinical. Total of 72 incised wounds on ventral side of 24 New Zealand rabbits' ears were divided randomly into two therapeutic groups (rhEGF group with 10 µg/cm(2) and rhßFGF group with 100 AU/cm(2)) and a control group (1% silver sulfadiazine cream, SD-Ag). The observation of wounds, the measurements of healing wound area, the calculation of wound closing index, the histopathological examination, the electrical microscopic examination, and the expression of examining integrin ß1 mRNA of samples of three groups by in situ hybridization technique were used to evaluate the results of wound healing. The results showed that the wound healing was accelerated in all wounds treated with rhEGF and rhßFGF, and the quality of healing wounds of two therapeutic groups was better than that of the control group. In rhßFGF group, new granulation tissue was more than that of rhEGF group in earlier period and metaphase of healing wound, however, the velocity of re-epithelialization in rhEGF group was faster than that of rhßFGF group in metaphase and late period. The results indicate that rhEGF and rhßFGF can improve wound healing, but the detailed mechanisms and the biological effects were different. rhßFGF may be used to promote the growth of granulation tissue in earlier period and metaphase of healing wound, however, rhEGF may be used to accelerate the velocity of re-epithelialization in metaphase and late period. That rhßFGF and rhEGF were utilized in sequence can not only accelerate the velocity of healing wound and promote the quality of healing wound but also obtain the best ratio of effects versus value.

BMP-7 attenuates TGF-ß1-induced fibroblast-like differentiation of rat dermal papilla cells.

Dermal papilla cells (DPCs) show phenotypic plasticity during wound healing. The multipotency of DPCs is well recognized, but the signaling pathways that regulate the differentiation of these cells into fibroblasts are poorly understood. A preliminary experiment showed that transforming growth factor beta1 (TGF-ß1) can induce DPCs to differentiate into fibroblast-like cells, which suggests that DPCs may be a source of wound-healing fibroblasts. Bone morphogenetic protein-7 (BMP-7), a member of the TGF-ß superfamily, can prevent and reverse fibrosis by counteracting the TGF-ß1-mediated profibrotic effect. To determine whether BMP-7 attenuates the TGF-ß1-induced differentiation of DPCs into fibroblasts, we established an in vitro system for DPC differentiation and recorded the gene expression patterns that distinguished DPCs from fibroblasts. The proportion of fibroblast-like cells was significantly enhanced in DPCs treated with TGF-ß1, as evidenced by immunocytochemistry, flow cytometry, quantitative real-time reverse transcriptase polymerase chain reaction, and Western blot analysis. BMP-7 and TGF-ß1 administration substantially decreased fibroblast-like differentiation, indicating inhibition of TGF-ß1-induced differentiation. The antagonistic BMP-7- and TGF-ß1-activated signaling pathways can be used to promote wound healing or suppress hypertrophic scarring.

[Effect of Col I A1 antisense oligodeoxynucleotide on collagen synthesis in human hypertrophic scar transplanted nude mouse model].

UNLABELLED: Objective Col I A1 antisense oligodeoxynucleotide (ASODN) has inhibitory effect on collagen synthesis in cultured human hypertrophic scar fibroblasts. To investigate the effects of intralesional injection of Col I A1 ASODN on collagen synthesis in human hypertrophic scar transplanted nude mouse model. METHODS: The animal model of human hypertrophic scar transplantation was established in the 60 BALB/c-nunu nude mice (specific pathogen free grade, weighing about 20 g, and aged 6-8 weeks) by transplanting hypertrophic scar without epidermis donated by the patients into the interscapular subcutaneous region on the back, with 1 piece each mouse. Fifty-eight succeed models mice were randomly divided into 3 groups in accordance with the contents of injection. In group A (n = 20): 5 microL Col I A1 ASODN (3 mmol/L), 3 microL liposome, and 92 microL Opti-MEM I; in group B (n = 20): 3 microL liposome and 97 microL Opti-MEM I; in group C (n = 18): only 100 microL Opti-MEM I. The injection was every day in the first 2 weeks and once every other day thereafter. The scar specimens were harvested at 2, 4, and 6 weeks after injection, respectively and the hardness of the scar tissue was measured. The collagens type I and III in the scar were observed under polarized light microscope after sirius red staining. The ultrastructures of the scar tissues were also observed under transmission electronic microscope (TEM). Additionally, the Col I A1 mRNAs expression was determined by RT-PCR and the concentrations of Col I A1 protein were measured with ELISA method. RESULTS: Seventeen mice died after intralesional injection. Totally 40 specimens out of 41 mice were suitable for nucleic acid and protein study, including 14 in group A, 13 in group B, and 14 in group C. The hardness of scars showed no significant difference (P > 0.05) among 3 groups at 2 weeks after injection, whereas the hardness of scars in group A was significantly lower than those in groups B and C at 4 and 6 weeks (P < 0.05), and there was no significant difference between groups B and C (P > 0.05). The collagen staining showed the increase of collagen type III in all groups, especially in group A with a regular arrangement of collagen type I fibers. TEM observation indicated that there was degeneration of fibroblasts and better organization of collagen fibers in group A, and the structures of collagen fibers in all groups became orderly with time. The relative expressions of Col I A1 mRNA and the concentrations of Col I A1 protein at 2 and 4 weeks after injection were significant difference among 3 groups (P < 0.05), and they were significantly lower in group A than in groups B and C (P < 0.05) at 6 weeks after injection, but no significant difference was found between groups B and C (P > 0.05). CONCLUSION: Intralesional injection of Col I A1 ASODN in the nude mice model with human hypertrophic scars can inhibit the expression of Col I A1 mRNA and collagen type I, which enhances the mature and softening of the scar tissue. In this process, liposome shows some assistant effect.

[Inhibitory effect of human Col I A1 antisense oligodeoxynucleotide on collagen synthesis in hypertrophic scar fibroblasts].

OBJECTIVE: To investigate the inhibitory effect of Col I A1 antisense oligodeoxynucleotide (ASODN) transfection mediated by cationic liposome on Col I A1 expression in human hypertrophic scar fibroblasts. METHODS: Scar tissue was obtained from volunteer donor. Human hypertrophic scar fibroblasts were cultured by tissue block method. The cells at passage 4 were seeded in a 6 well cell culture plate at 32.25 x 10(4) cells/well, and then divided into 4 groups: group A, liposome and Col I A1 ASODN; group B, Col I A1 ASODN; group C, liposome; group D, blank control. At 8 hours, 1, 2, 3 and 4 days after transfection, total RNA of the cells were extracted, the expression level of Col I A1 mRNA was detected by RT-PCR, the Col I A1 protein in ECM was extracted by pepsin-digestion method, its concentration was detected by ELISA method. RESULTS: Agarose gel electrophoresis detection of amplified products showed clear bands without occurrence of indistinct band, obvious primer dimmer and tailing phenomenon. Relative expression level of Col I A1 mRNA: at 8 hours after transfection, group A was less than groups B, C and D (P < 0.05), and groups B and C were less than group D (P < 0.05), and no significant difference was evident between group B and group C (P > 0.05); at 1 day after transfection, groups A and B were less than groups C and D (P < 0.05), and there was no significant difference between group A and group B, and between group C and group D (P > 0.05 ); at 2 days after transfection, there were significant differences among four groups (P < 0.05); at 3 and 4 days after transfection, group A was less than groups B, C and D (P < 0.05), group B was less than groups C and D (P < 0.05), and no significant difference was evident between group C and group D (P > 0.05). Concentration of Col I protein: at 8 hours after transfection, group A was less than groups B, C and D (P < 0.05), groups B and C were less than group D (P < 0.05), and no significant difference was evident between group B and group C (P > 0.05); at 1 day after transfection, significant differences were evident among four groups (P < 0.05); at 2, 3 and 4 days after transfection, groups A and B were less than groups C and D (P < 0.05), and no significant difference was evident between group A and group B (P > 0.05). CONCLUSION: Col I A1 ASODN can inhibit mRNA and protein expression level of Col I A1. Cationic liposome, as the carrier, can enhance the inhibition by facilitating the entry of ASODN into cells and introducing ASODN into cell nucleus.

Effects of antisense oligodeoxynucleotide to type I collagen gene on hypertrophic scars in the transplanted nude mouse model.

BACKGROUND: Antisense nucleic acids are effective in inhibiting harmful or uncontrolled gene expression. We had previously proved that the antisense DNA to type I collagen could effectively inhibit the synthesis of collagen type I in cultured hypertrophic scar fibroblasts, suggesting a potential role in anti-scarring, but there are no published reports of its effect on scar in the transplanted nude mouse model. AIMS: To investigate the effects of antisense oligodeoxynucleotide (ASODN) to type I collagen gene on hypertrophic scars in the transplanted nude mouse model and clarify the potential of ASODN for the treatment of scars. METHODS: The nudemousemodel of hypertrophic scar was created and subjected to daily injections with ASODN and LipofectamineTM for 2 ,4 or 6 weeks.We then examined the scars for changes in histopathological characteristics. The effects of ASODNon type I collagen gene expression were examined by reverse transcription-polymerase chain reaction and Western blots. RESULTS: The ASODN could remarkably alleviate the scar in the nude mouse model and consistently inhibit type I collagen gene expression at both the mRNA and protein levels. CONCLUSION: ASODN was effective in downregulating type I collagen gene expression and could prove to be useful in the treatment of scars.

Expression of Smad protein by normal skin fibroblasts and hypertrophic scar fibroblasts in response to transforming growth factor beta1.

BACKGROUND: Smad proteins are important intracellular mediators of transforming growth factor (TGF)-beta signaling. Little has been known about the specific relationship between TGF-beta and TGF-beta/Smad signaling in hypertrophic scars. OBJECTIVE: The objective was to investigate the expression of Smads and the specific relationship between TGF-beta and TGF-beta/Smad signaling in hypertrophic scars. METHODS: In this study, we initially determined the endogenous protein levels of Smad2 and Smad7 in hypertrophic scar fibroblast (HSFs) and normal skin fibroblast (NSFs). Second, we stimulated HSFs and NSFs with recombinant human TGF-beta1 for 24 hours to determine whether the TGF-beta1 could potentiate its effect by further stimulating the production of Smad by reverse transcription-polymerase chain reaction and Western blot analysis. RESULTS: When compared with NSFs, the endogenous expression of Smad2 in HSFs was up-regulated and TGF-beta1 could further stimulate the production of Smad2. Although the levels of Smad7 were similar between HSFs and NSFs, TGF-beta1 up-regulated the expression of Smad7 for NSFs only, with no discernible effect on HSFs. These changes were paralleled by a significant increase in cytoplasm-to-nuclear translocation of Smad2. CONCLUSION: These data substantiated the model of an autocrine positive loop in hypertrophic scars pathogenesis. The authors have indicated no significant interest with commercial supporters.

Effects of basic fibroblast growth factors on hypertrophic scarring in a rabbit ear model.

BACKGROUND: Basic fibroblast growth factor (bFGF) was clinically proven to accelerate acute and chronic wound healing. Accelerated wound healing may lead to improved scarring. These studies suggested a possible antiscarring effect of bFGF during wound healing. Little was known about the precise pathologic mechanisms of bFGF on scarring formation. AIMS: The aim of this study was to investigate the effect of bFGF on hypertrophic scarring in a rabbit ear model and clarify the mechanism of bFGF on scar treatment. METHODS: The rabbit model of hypertrophic scarring was created and received of a low- or high-dose topical treatment three times daily for 1, 2, or 3 months. Then we examined the changes in the macroscopic and histopathologic characteristics of the scars. The expression of collagen, alpha(1)beta(2) integrin, and matrix metalloproteinase 1 (MMP-1) was studied by applying reverse transcriptase-polymerase chain reaction, enzyme-linked immunosorbent assay, and Western blotting. RESULT: High-dose bFGF remarkably alleviated the scar in the rabbit ear model and decreased collagen type I expression. Further study revealed that bFGF remarkably enhanced MMP-1 and decreased alpha(1)beta(2) integrin expression. CONCLUSION: This study supports the hypothesis that bFGF exerted a net negative effect on collagen remodeling, therefore suggesting a potential antiscarring role.

Experimental study on repairing of nude mice skin defects with composite skin consisting of xenogeneic dermis and epidermal stem cells and hair follicle dermal papilla cells.

OBJECTIVE: To investigate the influence of hair follicle dermal papilla cells (DPCs) on biological features of composite skin. METHODS: In the test group, xenogeneic acellular dermal matrix was employed as the frame, DPCs were seeded on the subcutaneous side, and epithelial stem cells onto the dermal papilla side of the dermal frame so as to construct a composite skin. In the control group, there was no DPC in the frame. The two kinds of composite skin were employed to cover skin defects on the back of the nude mice. Wound healing was observed 4 weeks after grafting and area was analyzed and contraction rate was calculated. The tissue samples in the grafted area were harvested for HE staining and the state of the composite skin was observed. The stress-strain curve of the sampled skin was measured, so as to calculate the maximal breaking power of the sample. The data were collected and statistically analyzed. RESULTS: HE staining indicated that the epithelial depth was increased (more than 10 layers of cells) in test group, with only 6-7 layers in control group. The skin contraction rate in test group on the 4th week after skin grafting (3.94+/-0.013)% was much lower than that in control group (29.07+/-0.018)% (P<0.05). It was indicated by biomechanical test that the stress-strain curve of the composite skin in the test group was closer to that of normal nude mice skin in comparison to that in control group. The maximal breaking force of the composite skin in test group was (1.835+/-0.035)N (Newton), while that in control group was (1.075+/-0.065)N (P<0.01). CONCLUSION: Reconstruction of epidermis in composite skin was promoted by dermal DPCs seeded in the dermal matrix frame. As a result, there was less skin contraction in the composite skin with DPCs, so that the biological characteristics of the skin were improved.

[Isolation and differentiation characteristics of dermal multipotent stem cells from humans of different ages cultured in vitro].

OBJECTIVE: To study isolation, identification and differentiation characteristics of dermal multipotent stem cells from human of different age in vitro culture. METHODS: Skin samples( 1 cm x 1 cm) were harvested from fetus, infant, adult and elderly. The original clones were screened in stem cell medium. The diameter and number of clones were recorded. Analysis of each clone and determination of the expression of various related proteins were carried out. RESULTS: The number of suspended clones from normal skins of fetus, infant, adult and the elderly were (20. 1 +/-2. 5) x 102 , (15. 8 +/-5. 7) x 102, (10. 8 +/-1.3) x 10(2), (6.2 +/- 1.4) x 10(2), respectively ( P <0.01), while the diameter of the clones from them were (83 +/-12) microm, (55 +/- 10) microm, (46 +/- 12) Lm, (42 +/-8) microm, respectively ( P <0.05). Cloned cells from fetus, infant, adult and elderly could differentiate into neuron cell , neuroglia cell, smooth muscle cell, and adipocyte. The clones from fetus were inclined to differentiate into neuron cells, but those from infant were inclined to differentiate into neuroglia cells, and those from adult and elderly were inclined to differentiate into adipocytes. After 1 month of culture, the clone forming rate of the cells from fetus, infant, adult and elderly were 41. 1% , 25.5% ,17.7% ,15.2% , respectively. The individual clone cells also showed ability of multidirectional differentiation. Nestin, fibronectin, c-Myc, STAT3 and hTERT protein were expressed in all clones. CONCLUSION: Multipotent stem cells with multi-direction differentiation and proliferation can be efficiently isolated from dermis of human of different age in stem cell culture medium. The number, proliferation and differentiation of dermal multipotent stem cells can be affected by age.

[Effects of citrus reticulata blanco extract on fibroblasts from human hypertrophic scar in vitro].

OBJECTIVE: To investigate the effects of citrus reticulata blanco extract on the proliferation and collagen metabolism of fibroblasts from human hypertrophic scar. METHODS: Human hypertrophic scar fibroblasts from two burn patients obtained from plastic surgery were cultured in vitro and divided into experimental group (n = 12, with basic culture medium and 2.5, 5.0, 10.0,25.0 mg/L citrus reticulata blanco extract, respectively, 3 bottles for each concentration of citrus reticulata blanco extract ), control group 1 (n = 3, with basic culture medium) , and control group 2 ( n = 3, with basic culture medium and 5% ethyl alcohol). The cell proliferation in each group was observed with MTT method, then the inhibition rate was calculated. Apoptosis and its index ( AI) in each group were determined after TUNEL staining . The changes in the content of ICTP and PINP in each group were observed by radioimmunity. RESULTS: The inhibition rate in the experimental group with the citrus reticulata blanco extract in concentration of 2. 5, 5.0, 10.0, 25. 0 microg/ ml were (7. 100+/-0.038)% , (8. 100+/- 0. 048)% , (10. 900+/-0. 055)%, (15.900+/-0. 097) %, respectively, which were significantly higher than those in other two groups ( P <0.05 ). The Al (69. 7% , 71.7%, 86.4% , 95.2% ), ICTP [(17.2+/-0.6), (18.3+/-0.6), (19.8+/-0.5), (23.2+/-0.6) microg/L] and PINP [ (101.7+/-1.4) , (107. 8+/-1. 1) , (111.6+/-1.2) , (124. 6+/-1.3) microg/L] in experimental group with the citrus reticulata blanco extract in concentration of 2.5, 5.0, 10.0 , 25.0 mg/L were also obviously higher than other two control groups( P <0.05) ,but these indices in control 1 group were similar to those in control 2 group( P >0. 05). CONCLUSION: The citrus reticulata blanco extract might be beneficial for the management of hypertrophic scar through inhibition of the proliferation of fibroblasts in hypertrophic scar, by promoting apoptosis and collagen degradation.

[Study on the regular pattern of the distribution of skin epidermal stem cells in the different parts of a healthy human body].

OBJECTIVE: To investigate the regular pattern of the distribution of skin epidermal stem cells (ESCs) in the different parts of a healthy human body, and to evaluate the feasibility of the identification of ESCs by P63 and CD29 with single and double labeling. METHODS: Full-thickness skin samples from 21 parts (including scalp, dorsum of foot, sole of foot, pubic region, and scrotum) of 5 healthy persons were harvested for the study. Immunohistochemistry method with biotin-streptavidin-horseradish peroxidase (SP) was employed with P63 and CD29 as the first antibody to carry out single and double labeling. The staining results were subjected to image analysis. The distribution of the ESCs in the skin from the above parts was observed and expressed as positive unit (PU) value. RESULTS: It was found by P63 single labeling and P63 and CD29 double labeling that the PU value in the dorsum of foot was the lowest while that in the scalp was the highest among all the parts of a healthy body. It was also found by CD29 single labeling that the PU value in the dorsum of foot was the lowest [(11.9 +/- 1.5)%] while highest in the scalp [(29.1 +/- 5.0)%]. The PU value in the hairy region of a human body was evidently higher than that in the non-hairy region (P < 0.01), when examined by P63 and CD29 single and double labeling. But there was no difference in the PU values between the trunk and limbs by means of P63 and CD29 single and double labeling (P > 0.05). CONCLUSION: There are more ESCs in the skin from the scalp, mons pubis and scrotum than other parts of the body. Single P63 or CD29 labeling exhibits higher sensitivity but lower specificity in the identification of ESCs. While the double labeling method exhibits higher specificity but lower sensitivity. Above all, it seems that the double labeling may be a simple and effective method for the identification of ESCs.

[Effect of asiaticoside on the expression of transforming growth factor-beta mRNA and matrix metalloproteinases in hypertrophic scars].

OBJECTIVE: To investigate the effect of asiaticoside on the expressions of transforming growth factor (TGF)-beta mRNA, matrix metalloproteinases (MMPS) and tissue inhibitors of metalloproteinases (TIMPs) in postburn hypertrophic scars. METHODS: Nine specimens of postburn (5-8 months) hypertrophic scars with asiaticoside treatment and 9 without asiaticoside treatment were collected for testing the expressions of MMPS, TIMPs, type I and III collagen and TGF-beta mRNA by immunohistochemistry and in situ hybridization methods, followed by image analysis of the results. RESULTS: The expressions of TGF-beta mRNA and MMPS/TIMPS were all detected in the fibroblast cytoplasm. The expression of TGF-beta(1) mRNA in asiaticoside-treated scars was significantly lower than that in scars without asiaticoside treatment (P<0.01). In contrast, the expression of TGF-beta(3) mRNA was significantly higher in asiaticoside group (P<0.05). The expression of TIMP1 in asiaticoside group was significantly lower than that in non-asiaticoside group (P<0.01), and the expression of type I collagen in asiaticoside-treated scars was lower than that in non-asiaticoside-treated specimens (P<0.05), but the expression of MMP(1), MMP(2) and TIMP(2) and type III collagen exhibited no significant differences between the two groups (P>0.05). CONCLUSION: Asiaticoside can down-regulate TGF-beta(1) mRNA and TIMP(1) expressions and up-regulate TGF-beta(3) mRNA expression in postburn hypertrophic scars, and is also capable of decomposing the products of type I collagen, contributing to the reduction of hypertrophic scar formation.