Search

BACKGROUND: Combined radiation and wound injury appeared mainly in patients with tumor radiotherapy and nuclear radiation accidents. The radiation destroys the repair mechanism, resulting in delayed or prolonged wound healing. It still lacks an effective therapeutic strategy currently. OBJECTIVE: To prepare multifunctional wound dressings based on the multiple clinical symptoms of combined radiation and wound injury, which are designed to be antibacteria, promoted healing and analgesics. METHODS: Using levofloxacin, fibroin and lidocaine hydrochloride as raw materials, 3D bioprinting technology was applied to prepare the multifunctional wound dressing. (1) The multifunctional dressing was placed on a fixed culture plate coated with Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, and incubated at 37 °C overnight to detect the diameter of the antibacterial zone. (2) 40 Kunming mice were randomly divided into trauma group, radiation and trauma model group, treatment group and positive drug group, with 10 mice in each group. Mice in the radiation and trauma model group, treatment group and positive drug group were irradiated by 60Co gamma rays. After 1 hour of radiation, a full-layer skin defect wound with a diameter of 1 cm was made on the back of each mouse in the four groups. Normal saline was applied to the wounds of the trauma group and the radiation and trauma model group. Trethanolamine cream was applied to the wounds of the positive drug group. Multifunctional dressing was applied to the wounds of the treatment group. The dressing was changed every 2 days, and the treatment was continued for 14 days. Wound healing rate and serum interleukin-6 level were measured at 3, 7 and 14 days after wound modeling. 14 days after the wound modeling, the skin tissue of the wound was obtained and received hematoxylin-eosin staining, Masson staining and cytokeratin-14 immunohistochemical staining. RESULTS AND CONCLUSION: (1) 3D-printed multifunctional wound dressing had good antibacterial activity. The antibacterial zone diameters against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were (4.15±0.09), (4.18±0.23) and (4.35±0.13) cm, respectively. (2) With the extension of modeling time, the wound healed gradually. The wound healing rate of the treatment group and the positive drug group was higher than that of the radiation and trauma model group at 3, 7 and 14 days after modeling (P < 0.01, P < 0.001). The wound healing rate of the treatment group was higher than that of the positive drug group. With the extension of modeling time, the serum interleukin level of mice increased first and then decreased. The serum interleukin level in the treatment group at 3, 7 and 14 days after modeling was lower than that in the radiation and trauma model group. Hematoxylin-eosin staining and Masson staining exhibited that inflammatory cells infiltrated the granuloma tissue in the trauma group, and the dermal collagen fibers were densely arranged. The normal structure of epidermis and dermis was destroyed and inflammatory cells were infiltrated in the radiation and trauma model group. In the treatment group, normal skin mucosal tissue was observed, the epidermis was arranged closely, and the sweat glands, hair follicles and dermal collagen fibers were arranged regularly. In the positive drug group, the arrangement of epidermal layer was tight, and the arrangement of sweat glands, hair follicles and dermal collagen fibers was regular. Cytokeratin-14 immunohistochemical staining displayed that the epidermal tissue thickness in the treatment group was lower than that in the other three groups (P < 0.01, P < 0.001). (3) The results confirm that the 3D-printed multifunctional dressing has multiple functions of local anesthesia, anti-infection and promoting healing. [ABSTRACT FROM AUTHOR]

BACKGROUND: How to provide sufficient skin resources for scar plastic surgery and repair of extensive deep burn patients while avoiding the re-proliferation of scar tissue in the surgical area has always been an important topic in burn and wound repair research. OBJECTIVE: To observe the clinical application effects of artificial dermis combined with autologous scar epidermis in the repair of scar after extensive burns. METHODS: Retrospective analysis was performed on 73 patients with scar hyperplasia and contracture deformity after extensive burns in Bengbu Third People’s Hospital Affiliated to Bengbu Medical College from January 2021 to January 2023. The patients were divided into three groups according to the treatment method: Group A (n=21, artificial dermis combined with autologous scar epidermis transplantation was used for treatment), group B (n=27, scar epidermis was transplanted after scar release in the functional site), and group C (n=25, functional site scar release after transplantation of thick skin treatment). Skin survival and infection at the receiving site, wound healing time at the receiving site and the donor site were recorded in the three groups. The scar status and functional recovery of the recipient area and donor area were evaluated by the Vancouver Scar Scale and activities of daily living. RESULTS AND CONCLUSION: (1) The skin infection rate was lower in group B than that in groups A and C (P < 0.05). The survival grade was higher in group B than that in groups A and C (P < 0.05). (2) The wound healing time at the receiving site was longer in group A than that in groups B and C (P < 0.05). The wound healing time at the receiving site was longer in group C than that in group B (P < 0.05). The wound healing time at the donor site was longer in group C than that in groups A and B (P < 0.05). (3) Vancouver Scar Scale score was higher in group B than that in groups A and C at 12 months postoperatively (P < 0.05). Vancouver Scar Scale score was higher in group C than that in groups A and B at 6 and 12 months postoperatively (P < 0.05). The excellent grade of activities of daily living in groups A and C was significantly higher than that of group B at 12 months postoperatively (P < 0.05). (4) The results showed that the application of artificial dermis combined with autologous scar epidermis composite transplantation in the treatment of scar contracture after extensive burn could not only achieve the same effect as that of intermediate-thickness skin, but also avoid postoperative scar re-hyperplasia at the donor site and shorten the time of complete wound healing at the donor site. Compared with scar epidermal transplantation, this treatment has obvious advantages. [ABSTRACT FROM AUTHOR]

This paper comprehensively discusses the pathways of heavy metals into the plant root epidermis, the short-range transport pathway through the horizontal transport of coplanar and plasmodesmata, and the long-range transport pathway through the xylem and phloem for loading and unloading. The transport of heavy metal ions by the coplanar pathway is slow, while the transport of heavy metal ions by the extra plastid pathway has low resistance to migration and high rate. Cell wall adsorption and resolution are en-dogenous factors affecting the transport of heavy metal ions into the root xylem via the cytoplasmic ectodomain pathway, but the development of the Casparian strip and suberin in the root cortex, which constitute the ectodomain barrier, can block the ectodomain pathway of heavy metal ion migration to the xylem. Plant transpiration and root pressure provide the driving force for the long-distance transport of heavy metal ions in the xylem and are related to the transpiration rate of plants. The mechanism of plant detoxification and tolerance to heavy metals is mainly induced by the production of metallothionein, the formation of phytoch-elating pep tides (PCs) in stressed plants and the regionalization of heavy metals by vesicles. [ABSTRACT FROM AUTHOR]

Objective To investigate the clinical efficacy of platelet-rich plasma (PRP)combined with lando bilayer artificial dermis in the treatment of bone/tendon exposure. Methods A total of 28 patients with bone/tendon exposure admitted to our department from January 2019 to May 2022 were selected as the research subjects. According to the random number table method, they were randomly divided into two groups, the control group (single lando bilayer artificial dermis) and the observation group (platelet-rich plasma combined with lando bilayer artificial dermis), with 14 cases in each group. After wound debridement, the observation group was injected with PRP, and covered with lando bilayer artificial dermis. The control group was covered only with artificial dermis. The granulation tissue coverage, wound healing time and scar score were compared between the two groups in the 2nd and 3rd weeks after surgery. Results All patients had effective coverage of bone or tendon exposure. However, the granulation coverage in the observation group was significantly higher than that in the control group in the 2nd and 3rd weeks. After granulation covering, 3 patients were treated with conservative treatment and 25 patients were treated with skin grafting. All patients healed well. The wound healing time of the observation group was shorter than that of the control group. The scar score of the observation group was significantly lower than that of the control group at 3 months after healing. Conclusion Platelet-rich plasma combined with lando bilayer artificial dermis can promote the growth of granulation tissue of bone/tendon exposure, shorten the healing time of wound, and improve the quality of wound healing. It can be used as one of the treatment methods for bone/tendon exposure, and is worthy of clinical promotion and application. [ABSTRACT FROM AUTHOR]

The fern genus Microlepia is a natural fern group, while large morphological differences of this genus lead to some classification controversies. The leaf epidermal micromorphology of 18 species( include 3 varieties )of Microlepia was observed and compared under light microscope( LM )and scanning electron microscope( SEM ). Hairs were on the veins of the upper and lower epidermis. The form of epidermal cells was irregular, with the anticlinal walls sinuous or sinuate. The stomatal apparatus of all species were restricted to abaxial epidermises and generally could be described as polocytic and axillocytic type, and copolocytic, coaxillocytic, aisocytic and anomotetracytic type only appears in a few species. The similarity of the micromorphological characteristics of leaf epidermis support that the genus Microlepia is a monophyletic group in Dentaedtiaceae. The hairs characteristics between veins of the leaves support that M. calvescens, M. marginata var. villosa and M. marginata var. bipinnata should be treated as a variety of M. marginata. Under SEM, the cuticle of the upper epidermis was mostly ridged, and most of them had filiform ornamentation. The characteristics of leaf cuticle ornamentation were correlated with pinnate compound leaves. The inner margin of the outer stomatal rim was often smooth, sinuous or odontoid. “T” sharp, upright outer stomatal rims occurred in most species, and outer stomatal ledge was mostly depressed. The differences among the leaf micromorphology of these species were shown, which provides references for the classification, evolution and system location of Microlepia. [ABSTRACT FROM AUTHOR]

In order to clarify the relationships in Rhododendron subg. Tsutsusi, micromorphological characters of leaf epidermis were examined for 37 species in Rhododendron subg. Tsutsusi using scanning electron microscopy(SEM), among which the relevant features of 29 species are reported for the first time. The results are as follows:(1)The stomatal apparatus are anomocytic and all on abaxial surface.(2)According to the micromorphological features of glands, trichome types and stomatal apparatus of leaf epidermis, subg. Tsutsusi can be divided into five types, i.e., R. simsii-type, R. mariae-type, R. indicum-type, R. saxatile-type and R. farrerae-type.(3)The plants in R. simsii-type have the similar morphological features, have no or discontinuous ringed striates around stomatal apparatus.(4)The plants in R. mariae-type do not have distinct T-pieces at the polar regions of guard cells but have multilayer ringed striates.(5)It is implied that the plants in R. indicum-type have the close affinity with subg. Therorhodion in having distinct T-pieces at the polar regions of guard cells.(6)R. saxatile-type differs from other types in its simple trichomes being virgate but without glands.(7)The leaf epidermis of R. farrerae-type has glands only.(8)The relationships between the closely related species are also discussed on the basis of leaf epidermal micromorphological features. For example, R. hypoblematosum and R. polyraphidoideum tend to be treated as separate species. Support the preservation of R. naamkwanense var. cryptonerve as a variety of R. naamkwanense, and do not support the R. adenanthum into R. tenue as a synonym. The results of this study show that micromorphological features of leaf epidermis are of significant value for species delimitation in subg. Tsutsusi. [ABSTRACT FROM AUTHOR]

BACKGROUND: Process integration of decellularization, antigen removal, viral inactivation and sterilization is essential for producing regenerative biomaterials that meet clinical requirements. OBJECTIVE: To systematically compare the effects of two combined processes of decellularization, antigen removal, virus inactivation and sterilization on the physicochemical properties of porcine dermal matrix. METHODS: Fresh porcine dermis was obtained and processed by two processes into acellular matrices. (1) Method A: 1% Triton X-100, DNase and RNase, and 1% tributyl phosphate were applied for decellularization, 1% peracetic acid and 25% ethanol for viral inactivation, and gamma-irradiation for terminal sterilization. (2) Method B: Dispase II, 0.5% Triton X-100 and DNase were used for decellularization, α-galactosidase for the antigen removal, 0.1% peracetic acid for viral inactivation and gamma-irradiation terminal sterilization. Porcine dermal matrices prepared by two methods were characterized. RESULTS AND CONCLUSION: (1) The collagen content of group A was lower than that of group B. The contents of elastin and sugar of group A were higher than those of group B. The material hardness value of group A was higher than that of group B. The drapability of the matrix material in group A was poor and the flexibility of the matrix material in group B was better. (2) The decellularization of group A did not affect the thermal stability of the matrix material. In group B, decellularization slightly reduced the thermal stability of the matrix material. After gamma ray sterilization, the thermal stability of the matrix material in group A decreased greatly and the thermal stability of the matrix material in group B decreased very little. (3) Compared with group B, the tensile strength and elasticity of the matrix material in group A were smaller. In vitro enzymatic degradation experiments showed that the matrix materials in group A had strong resistance to collagenase degradation, were sensitive to trypsin and were easily degraded; the matrix materials in group B were the opposite. (4) Scanning electron microscope showed that after sterilization by gamma rays, the three-dimensional structure of collagen could not be seen in the matrix material of group A; the collagen fibers were densely arranged, and there was a non-fibrous structural gel-like substance between the collagen fibers. In group B, the structure of collagen fibers in the matrix material was clear, and there was no non-fibrous structural glue-like substance between the collagen fibers. Hematoxylin-eosin staining and trichrome staining showed that after sterilization by gamma rays, a few nuclei were visible in the matrix material of group A; the collagen fibers were closely arranged, and the material was dense. The matrix material in group B had no nucleus and retained a good three-dimensional spatial structure of collagen fibers. (5) The results suggest that different processes have great influences on the physical and chemical properties of derived acellular matrices. Method B is effective in decellularizing and de-antigening and retains intact natural tissue matrix. Method A is more destructive to the material and results in lower collagen content, scratchability, thermal stability and poorer biomechanical properties compared with the Method B. [ABSTRACT FROM AUTHOR]

BACKGROUND: Recently, decellularized dermal matrix hydrogel has broad application prospects in tissue filling and repair because of its injectable and filling irregular space. Cytocompatibility and biocompatibility are the key to tissue repair. It is significant to explore the compatibility of decellularized dermal matrix hydrogel. OBJECTIVE: To construct a decellularized dermal matrix hydrogel scaffold for tissue filling and repair. METHODS: An injectable decellularized dermal matrix hydrogel was prepared, and its microscopic morphology was observed under a scanning electron microscope. The decellularized dermal matrix hydrogels with a concentration of 8 and 10 g/L were co-cultured with bone marrow mesenchymal stem cells, separately, and the cell proliferation and cytocompatibility were tested. The decellularized dermal matrix hydrogels with a protein concentration of 0.25 and 0.5 g/L were injected into different subcutaneous parts of the back of the same SD rat separately, and the degradation of the hydrogels was observed 2 and 4 weeks after the operation. Decellularized dermal matrix hydrogels with protein concentrations of 1, 1.5, and 2 g/L were injected into different subcutaneous parts of the back of the same SD rat separately. At 8 and 16 weeks after the operation, the degradation of the hydrogel was observed and histological analysis was performed. RESULTS AND CONCLUSION: (1) Scanning electron microscopy analysis showed that the decellularized dermal matrix hydrogel exhibited an irregular and randomly oriented porous fibrous structure with different pore sizes. (2) After 1, 3, and 5 days of co-culture, the hydrogels with the two concentrations had no effect on the proliferation of bone marrow mesenchymal stem cells. Live/Dead staining after 1, 2, and 3 days of co-culture showed that the hydrogels with the two concentrations had no effect on the proliferation of bone marrow mesenchymal stem cells, but the cell morphology on the hydrogel changed to some extent. (3) The hydrogel with a protein concentration of 0.25 g/L was degraded after subcutaneous injection for 2 weeks; the hydrogel with a protein concentration of 0.5 g/L was degraded after subcutaneous injection for 4 weeks; the hydrogels with a protein concentration of 1, 1.5, and 2 g/L did not degrade after subcutaneous injection for 16 weeks, and possibly even longer. Hematoxylin-eosin staining showed that after subcutaneous injection for 8 weeks, the hydrogel tissue of the three protein mass concentrations was relatively dense, with a small amount of inflammatory infiltration, and the 2 g/L group had microangiogenesis. After 16 weeks, the hydrogel tissue became loose, and the 1 g/L group was more obvious, and the inflammatory infiltration was alleviated. Immunohistochemical staining showed that the number of microvessels in the hydrogel increased with the increase of injection time. The number of microvessels in the hydrogel increased with the increase of protein concentration. (4) The results confirmed that the injectable decellularized dermal matrix hydrogel had good cytocompatibility and biocompatibility. [ABSTRACT FROM AUTHOR]

Objective To investigate the efficacy of artificial dermis for wound repair after resection of cutaneous malignant tumors. Methods Twenty-five inpatients with cutaneous malignant tumors, including basal cell carcinoma (16 cases), squamous cell carcinoma (7 cases), and dermatofibrosarcoma protuberans (2 cases), were enrolled from our hospital. Among these patients, either their wound could not be repaired with traditional skin flaps or they had underlying medical conditions. Tumors were removed by Mohs microsurgery, followed by placement of artificial dermis on the wound. Results Complete wound repair was observed in all patients. Of the 25 patients, 23 cases (92.00%) showed complete wound healing with mild hypertrophic scar within 1-2 months post-surgery. All wounds were healed within 3 months after the surgery. Only mild hypertrophic scars were observed during six-month follow-up. Conclusions Artificial dermis is effective for wound repair after resection of cutaneous malignant tumors, with mild hypertrophic scar, and is easy to use. [ABSTRACT FROM AUTHOR]

【Objective】This study aimed to evaluate the biocontrol potential of an entomogenous fungus strain isolated from Phenacoccus solenoposis, for providing the basis of its development as a biocontrol agent.【Method】 The strain was isolated and purified from the diseased P.solenoposis using tissue isolation method. Based on the cultural traits, morphological traits and phylogenetic tree analysis, its taxonomic ststus was clarified. The infection mode of strain on P.solenoposis was explored by scanning electron microscope，which clarified its ability to infect P.solenoposis. The pathogenicity of the strain to P.solenoposis was measured by leaf dipping and insect dipping method. 【Result】A strain FE-1 was isolated and purified from the diseased P.solenoposis, the morphological traits results showed that the colony diameter of strain FE-1 ranged from 50 to 60 mm at 5 days on PDA medium, and the colony was orange-white in front. The conidia morphology had two types, which small type was long column shape and large spore was sickle shape. The strain FE-1 was identified as Fusarium equiseti based on cultural traits, morphological traits and phglogenetic tree analysis. The strain FE-1 infected into the insect body cavity of P.solenoposis mainly by conidia germination forming germ tubes at the epidermis for growing horizontally, and the formation of expanded appressorium at the specific contact epidermis, which clarified its ability to infect P.solenoposis. The results of indoor toxicity measuremerts showed that the pathogenicity of strain FE-1 against female adults of P.solenoposis was gradually increased with the concentration of conidial suspension. At the spore concentration of 1×108 CFU / mL, LT50 was 3.32 days, while at 7 days after inoculation, the adjusted mortality of P.solenoposis female adults was 87.50±1.79%, LC50 was 1.8×105 CFU /mL. 【Conclusion】A strain FE-1 isolated and purified from the diseased P.solenoposis can form expanded appressorium at the specific contact epidermis for infection, which clarifies its ability to infect P.solenoposis. Meanwhile, the strain FE-1 is highly pathogenic against P.solenoposis, which has great potential for biocontrol and provide original material for the biocontrol research of P.solenoposis. [ABSTRACT FROM AUTHOR]

BACKGROUND: Sodium dodecyl sulfate is commonly used for decellularization of allogeneic matrix, whereas it is hard to remove from matrix. Only a small amount of sodium dodecyl sulfate in matrix can cause cytotoxicity. OBJECTIVE: To provide a high effective method to remove sodium dodecyl sulfate, which residuals in allogeneic matrix. METHODS: The pure water, potassium salt solution and ethanol were chosen to remove sodium dodecyl sulfate. The decellularization degree, residual amount of sodium dodecyl sulfate, composition, structure and tensile properties and cytotoxicity of allogeneic dermis and allogeneic tendon were detected to evaluate the cleaning effect. RESULTS AND CONCLUSION: In total, ethanol + potassium chloride and 75% ethanol + potassium chloride produced little significant impacts on the component and structure of allogeneic matrix. Firstly, on condition that sodium dodecyl sulfate was infiltrated into allogeneic matrix since DNA amount was controlled under 50 ng/mg (dry weight), the sodium dodecyl sulfate residual results showed a tremendous reduction of 96.7% and 97% in allogeneic dermis and allogeneic tendon, respectively. Secondly, no significant changes occurred in allogeneic dermis and allogeneic tendon for glycosaminoglycan and collagen. Moreover, after carefully washing, the allogeneic tendon exhibited higher the maximum tensile force, strength, and modulus than those after decellularization. Meanwhile, there was no significant difference compared with the raw material. Finally, the cytotoxicity test showed that cell viability was higher than 80% after washing of allogeneic dermis and allogeneic tendon; the cytotoxicity grade was not greater than lever 1. [ABSTRACT FROM AUTHOR]

Systemic sarcoidosis is a granulomatous disease involving multiple organs and systems. A 36-year-old woman was admitted due to multiple nodules of the trunk for 4 months. Upon admission, laboratory and auxiliary examinations were performed. A biopsy specimen revealed multiple nodules in the superficial dermis, which were composed of cells with abundant cytoplasm, large cell body and round or oval nuclei. PET/CT revealed systemic multiple lymph node enlargement complicated with active metabolism. She was eventually diagnosed with systemic sarcoidosis. After combined treatment of methylprednisolone, hydroxychloroquine and tofacitinib for 4 months, the skin lesions were significantly mitigated and no new skin lesions were found. This case prompts that Janus kinase inhibitors can be used to replace conventional immunosuppressants with reproductive toxicity for systemic sarcoidosis patients of reproductive age. [ABSTRACT FROM AUTHOR]

BACKGROUND: As a skin substitute, acellular dermal matrix has broad prospects and market. OBJECTIVE: To review the clinical application of acellular dermal matrix. METHODS: The authors searched PubMed, CNKI and Wanfang databases for articles published from 2000 to 2021 with the key words of “acellular dermal matrix, reconstruction/repair/plastic/clinical study” in English and Chinese, separately. Finally, 64 articles were included for review. RESULTS AND CONCLUSION: Acellular dermal matrix, characterized by rapid vascularization, low antigenicity, good histocompatibility and stable physicochemical properties, is a commonly used biological material in operations in the head and neck surgery, breast surgery, burn plastic surgery, gynecology, and urology. The main problem lies in its low output and the complicated production process to meet the medical standards. Thus, the price of acellular dermal matrix used in clinical use is high, increasing the medical economic burden of patients. Although most of the alloantigen substances are removed, acellular dermal matrix is still a foreign material for patients, so there is still a risk of surgical complications, such as rejection and infection. For future acellular dermal matrix, it is necessary to optimize the production process, improve the production process, reduce the production cost and increase the commercial specifications. From improving the decellularization process, it further removes proteins and other allergens from the acellular dermal matrix while preserving the dermal matrix, further reduces the immunogenicity of the acellular dermal matrix, enhances its compatibility, and reduces adverse events, such as infection and rejection. [ABSTRACT FROM AUTHOR]

Objective To explore the clinical efficacy of artificial dermis in the treatment of scar contracture after skin grafting in large area burn. Methods The clinical data of 30 patients with scar contracture after large area burn from October 2012 to October 2020 were retrospectively analyzed. Patients received autologous medium-thickness skin graft were served as control group and patients received artificial dermis combined with autologous split-thickness skin graft were served as experimental group, 15 cases in each group. The age, gender and scar area of patients were recorded. The healing time and survival rate of skin grafting between 2 groups were compared. All patients were followed-up for 1 year. The scars in recipient site and donor site before and after operation were evaluated by Vancouver Scar Scale (VSS). Patient satisfaction was recorded. Results There was no significant difference in gender, age and total area of scar between the control group and experimental group (P>0.05). The wound healing time of donor site in the experimental group was significantly shorter than that in the control group (t=3.16, P=0.01). The survival rate of skin grafting in the control group was significantly lower than that in the experimental group (t=2.87, P=0.01). The results of one-year follow-up showed that the VSS score of donor site in the control group was significantly higher than that in the experimental group (t=3.03, P=0.01), and the VSS score in the experimental group was better than that in the control group (P<0.05). Patient satisfaction in the experimental group was better than that in the control group (P<0.05). Conclusion The combined transplantation of artificial dermis and autologous skin grafting can obtain good clinical efficacy in the treatment of scar after large area burn, with good postoperative recovery and high patient satisfaction. [ABSTRACT FROM AUTHOR]

BACKGROUND: It is believed that leptin receptor (LepR) marks the adult bone marrow mesenchymal stem cells in mice and LepR+ cells contribute to the regeneration of fractured bone. However, the residence of LepR+ stromal cells in skin and the function of the population in skin development and repair are poorly understood. OBJECTIVE: To investigate the expression of LepR in mouse skin and the role of LepR+ cells in development and tissue repair. METHODS: The study was approved by the Experimental Animal Ethics and Use Committee of Shanghai Jiao Tong University with the approval No. 1504002. The LepR-Cre; tdTomato mice were generated by using the classic Cre-loxP system for tracing the expression of LepR in mouse skin. Flow cytometry was used to analyze surface markers on Tomato+ cells. A full-thickness skin excision wound model was constructed on the back of LepR-Cre; tdTomato mice to trace the distribution of LepR+ cells in skin wound healing. The LepR-Cre; Tsc1fl/fl mice for specific deletion of Tsc1 in LepR+ cells were constructed to identify the role of Tsc1 in mouse skin development. [ABSTRACT FROM AUTHOR]

Keratin can provide the structural foundation and protection for specific functions of keratinocytes against a variety of adverse environmental factors. The keratin of hoof toe is formed by epidermal cells through a complex differentiation process called keratinization. The keratinization of hoof epidermis can be controlled and regulated by a variety of bioactive molecules and hormones. The management and control of differentiation process and nutrient flow of epidermis cells are the key factors determining the quality and functional integrity of hoof cutin. Keratinization of epidermal cells reduces the supply of trace elements, leading to the production of low quality keratinization, thus increasing likelihood of ruminant hoof damage due to environmental factors. The paper reviews the effect of trace elements on keratinization, to provide reference for the application of trace elements in keratinization of hooves of ruminants. [ABSTRACT FROM AUTHOR]

BACKGROUND: In recent years, the combined transplantation of acellular allogeneic dermis and autologous split-thickness skin has achieved good results in burn wound repair at functional sites; however, few reports have documented the application of this technology in the repair of diabetic foot wounds. OBJECTIVE: To evaluate the clinical value of co-transplantation of acellular allogeneic dermis and autologous split-thickness skin in the repair of diabetic foot wound. METHODS: A retrospective analysis was made on the clinical data of 52 patients with diabetic foot wound who were treated with co-transplantation of acellular allogeneic dermis and autologous split-thickness skin (experimental group, n=26) or with autologous split-thickness skin (control group, n=26) between May 2017 and April 2020. The number of postoperative wound infection, skin graft survival rate, reoperation rate, wound healing time and wound recurrence rate during the 1-year follow-up period were compared between the two groups. An approval was obtained from the Ethics Committee of Beijing Shijitan Hospital, Capital Medical University. Informed consent was obtained from all patients and their relatives. RESULTS AND CONCLUSION: In the control group, eight patients developed infection in the skin graft area after operation, and among them, six patients had skin graft necrosis. After secondary operation, 2 out of the 6 patients healed after dressing treatment. In the experimental group, two patients developed infection after operation, and their wounds failed to be repaired but healed after dressing. The survival rate of skin graft in the experimental group (92.3%) was significantly higher than that in the control group (69.2%; P < 0.05). The reoperation rate of the experimental group was significantly lower than that of the control group (0 vs. 23.1%; P < 0.05). The wound healing time in the experimental group was (16.15±2.68) days, which was significantly shorter than that in the control group [(21.92±3.05) days; t=-7.25, P < 0.05]. The patients in both groups were followed up for 3 months to 1 year after operation. During the follow-up period, two patients in the experimental group and nine patients in the control group were re-hospitalized after wound recurrence. The wound recurrence rate in the experimental group was significantly lower than that in the control group (7.7% vs. 34.6%; P < 0.05). Therefore, compared with autologous split-thickness skin graft, the co-transplantation of acellular allogeneic dermis and autologous split-thickness skin can promote the survival of the skin and shorten the healing time of the wound. The repaired wound is friction-resistant, which reduces the recurrence of diabetic foot wound, even though there is an increase in hospital cost. [ABSTRACT FROM AUTHOR]

To study the synergistic effects and synergistic mechanism of three synergists on bentazon, glufosinate-ammonium and haloxyfop-P-methyl, and screen out the synergist with the best performance, the static surface tension (SST), dynamic surface tension (DST), dynamic dryness and contact angle of herbicides, synergists and synergists-added herbicides were investigated and adhesion force and adhesion work were calculated. The physicochemical performance tests revealed that the synergist based on isomeric alcohol ethoxylates performed best in reducing SST, accelerating the reduction of DST and reducing the contact angle, and the synergist based on penetrant T was the second most effective, while the synergist based on methyl oleate had a slight effect and was the worst. The data of adhesion force and adhesion work showed that the herbicide solution containing isomeric alcohol ethoxylates based synergist had stronger adhesion on the leaves and was easier to retain and wet the leaf epidermis. Meanwhile, the results of the indoor efficacy evaluations also confirmed that the synergist isomeric alcohol ethoxylates that had the best physicochemical performance exhibited the best control efficacy when added to herbicides as the main component of a synergist. [ABSTRACT FROM AUTHOR]

The distribution of the rare perennial fern Adiantum reniforme var. sinense(Pteridaceae)which is endemic to shady cliff environments is limited to small areas of Wanzhou and Fuling, Chongqing, China. In order to reveal the growth characteristics of A. reniforme var. sinense in the germplasm resource nursery,we observed the tissue structure of A. reniforme var. sinense, which including in the roots, rhizomes, leaves grown in the sun and in shade. First of all, the roots, rhizomes, leaves were collected and fixed in formaldehyde-alcohol-acetic acid solution, and we cut the tissue structure of the plant with a double-sided blade to make freehand sections, then the tissue were stained with three kinds of 0.1% Sudan red, 0.1% berberine bisulfate-aniline blue, and 0.05% toluidine blue, at last plant tissue sections were observed under the Lycra optical microscope and the fluorescence microscope. In this study, we used brightfield and epifluorescence microscopy to investigate the anatomical structures and histochemical features that may allow this species to thrive in shady, dry cliff environments. The results were as follows:(1)The A. reniforme var. sinense sporophyte had a primary structure, the roots had an endodermis with Casparian walls, suberin lamellae, a thickened sclerenchyma layer around the endodermis, a cortex, and a rhizodermis.(2)The stems had a dictyostele, an endodermis with Casparian walls and suberin lamellae, a thickened sclerenchyma layer around the endodermis, a cortex, and a thin cuticle.(3)The leaves had an endodermis surrounded the vascular bundles, a peripheral sclerenchyma layer, an isolateral mesophyll, a lignified epidermis and a thin cuticle.(4)The dictyostele, endodermis, sclerenchyma layers, and lignified epidermal walls reflected the drought tolerance of A. reniforme var. sinense, while its thin cuticle and isolateral mesophyll suggested tolerance of shady environments. Thus, according to the anatomical characteristics of A. reniforme var. sinense, it is concluded that A. reniforme var. sinense are consistent with adaptations to shady, dry cliff environments [ABSTRACT FROM AUTHOR]

Sphingomyelin (SM) is a constituent of cellular membranes, while ceramides (Cer) produced from SM on plasma membranes serve as a lipid mediator that regulates cell proliferation, differentiation, and apoptosis. In the skin, SM also is a precursor of Cer, an important constituent of epidermal permeability barrier. We investigated the role of epidermal SM synthase (SMS)2, an isoform of SMS, which modulates SM and Cer levels on plasma membranes. Although SMS2-knockout (SMS2-KO) mice were not neonatal lethal, an ichthyotic phenotype with epidermal hyperplasia and hyperkeratosis was evident at birth, which persisted until 2 weeks of age. These mice showed abnormal lamellar body morphology and secretion, and abnormal extracellular lamellar membranes in the stratum corneum. These abnormalities were no longer evident by 4 weeks of age in SMS2-KO mice. Our study suggests that (1) exposure to a dry terrestrial environment initiates compensatory responses, thereby normalizing epidermal ichthyotic abnormalities and (2) that a nonlethal gene abnormality can cause an ichthyotic skin phenotype. [ABSTRACT FROM AUTHOR]

In order to explore the difference and taxonomic significance through the characteristics of the lenticel, stomatal apparatus and lower epidermis of leaf of different kiwifruit species, the optical microscope was used to observe kiwifruit lenticels on one-year-old phloem of nine samples from five different species. Kiwifruit lenticels showed long elliptical or spindle shape. The values of length × width, lenticle density, lenticle area and percentage of lenticle area of different species were different and no obvious rule with species division. However, the four Actinidia chinensis varieties from selected samples could be clearly distinguished by the width of the lenticels. The results of scanning electron microscope showed that the stomatal apparatus only existed in blade back and mesophyll area with wide oval and elliptical shape, and the stomatal apparatus types were actinotytic, cyclocytic, anisocytic and anomocytic. Among these species, the stomatal apparatus shape of A. chinensis was actinotytic, the stomatal apparatus shape of A. deliciosa was cyclocytic, the stomatal apparatuses shapes of A. latifolia and A. eriantha were anisocytic, and the stomatal apparatus shape of A. longicarpa was anomocytic. Guard cells were arranged around stomatal apparatus, horizontal or protruding from the lower epidermis. The lower epidermal cells were papillose or anomocytic with sinuate or sinuolate anticlinal wall. The lower epidermis was granulated with furcal pubescence and bifurcate single cell without glandular trichome. Some germplasm had papillose or flake-like waxy layer. Inner margin of outer stomatal rim were sinuolate with ornamentation. According to the measure of length × width, axis and density of stomatal apparatus, there was no obvious rule with kiwifruit species division. However, the stomatal apparatus type and the species division were consistent well. Four A. chinensis varieties could be distinguished by the length, axis of stomatal and density of stomatal apparatus. In addition, there were significant differences in the microapparent morphology between A. longicarpa and other species, which provides microcosmic basis for its identification [ABSTRACT FROM AUTHOR]

BACKGROUND: Wnt5a is the only signaling molecule that is highly expressed in the dermis and closely related to the occurrence of hair follicle dermal components. OBJECTIVE: To preliminarily discuss initiation mechanism of dermal papilla embryogenesis and regeneration in vitro by observing Wnt5a expression of E12.5-E15.5 fetal rat skin and the upper part of tentacle hair follicle during dermal papilla regeneration induced by transplantation. METHODS: The pregnant Sprague-Dawley rats at E12.5, E13.5, E14.5 and E15.5 days were killed under anesthesia. The embryos were taken out to make paraffin sections. The hairy papilla was removed from the tentacle hair follicles of Sprague-Dawley rats, and the hair follicles were removed from the upper segment of the hair follicles and then injected into the skin of the back of Nu/Nu nude mice. The skins of rat embryos at above gestational age and hair follicles at transplanted back positions of the nude mice were taken. Enzymatic immunohistochemical method was used to observe the Wnt5a expression in rat embryonic skin and the upper segment of hair follicle during dermal papilla regeneration induced by transplantation. Hematoxylin-eosin staining was used to observe the regeneration of the inferior segment of hair follicle after transplantation in the upper segment. The animal experiment was approved by the Animal Ethics Committee of Shantou University Medical College. RESULTS AND CONCLUSION: (1) E12.5 Wnt5a was expressed in epidermal cells; E13.5 Wnt5a was expressed in epidermal cells and enhanced; E14.5 Wnt5a was transferred from epidermis to dermis and expressed in dermal cytoplasm; E15.5 Wnt5a was expressed in dermal connective tissue, obviously enhanced, and disappeared in epidermis. (2) From the third day to the ninth day after transplantation of the upper part of the rat hair follicle, the upper fragment of the hair follicle was observed to be growing downward. The complete follicles were re-formed. Wnt 5A was strongly expressed in the regeneration related tissues. (3) The high expression of Wnt5a in the site of dermal papilla formation in this model and dermal papilla embryogenesis suggests that Wnt signaling pathway is closely related to the regeneration of dermal papilla, and Wnt5a may play a very important role. [ABSTRACT FROM AUTHOR]

[Objective] Because of the serious disease problem of Iitopenaeus vannamei, it is important to study the disease resistance genes of L. vannamei. In this study, the WAP gene of L. vannamei was cloned and its tissue expression and anti-disease function were analyzed to provide reference for the development of anti-disease drugs for L. vannamei. [Method] The specific primers of W AP gene were designed, and the expression and distribution of the W AP gene in 11 tissues including blood cells, eye stem, gills, hepatopancreas, heart, stomach, muscle, nerve, intestine, cecum and epidermis were detected by RT-PCR. The W AP expression in gills and intestinal tissues of L. vannamei was detected by fluorescence quantitative PCR. The recombinant W AP protein was produced and the binding ability of recombinant W AP to LPS, PGN and LTA was analyzed by ELISA. [Result] It was found that WAP gene was expressed in all 11 tissues tested, with the highest expression in blood cell and the lowest expression in epidermis, eye stalk and hepatopancreas. The W AP gene expression was significantly increased in gill and intestinal tissues of infected L. vannamei compared with that of normal L. vannamei ( P < 0. OS) . The expression of WAP gene in the gill and intestinal tissues of infected L. vannamei were as 5. 9258 and 1. 5147 times as that of healthy L. vannamei,respectively. The recombinant W AP fusion protein could bind to bacterial polysaccharides LPS, PGN and LTA directly, and the order of binding ability was PGN > LPS > LTA. [Conclusion] The WAP gene was closely related to the disease resistance and immune function of L. vannamei, W AP fusion protein has potential in developing anti white feces drugs for L. vannamei. [ABSTRACT FROM AUTHOR]

[Objective (Study on tissue microstructure and histochemistry localization from different organs of could clarify the histological characteristics and the distribution and accumulation characteristics of the main chemical components of kingianum.【Method] The cross section of root, rootstock, stem and la of Polygonatum kingianum. were prepared, and the histological structure of each organ was observed by microscopy. The distribution and quantity of polysaccharides and saponins were analyzed by histochemical localization.【Result] The histomorphology and structural characteristics of the organs of POygona/m Vng—num were clarified. The Polysaccharides were mainly distributed in cortical parenchyma, vascular bundles and a few sclerenchyma cells. The Saponins were mainly distributed in epidermis, cortex parenchyma and sclerenchyma cells. The order of distribution of the two substances in each organ from high to low was rootstock, leaf, stem and root.【Conclusion] The tissue structural characteristics of the vegetative organs of POygonatum kingianum could be used as a basis for the identification of medicinal materials. The distribution of polysaccharide and saponin was found in all four organs, but the distribution of polysaccharide and saponin was different in different parts and tissues. In the same visual field, the content of leaves and other parts was relatively high, so we should pay attention to the development and utilization of non-medicinal parts such as leaf, stem and root. This study could provide a reference for the comprehensive utilization of Polygonatum kingianum resource1. [ABSTRACT FROM AUTHOR]

Objective: To investigate the clinical features, predisposing factors, pat ho logical features, genetic mechanism, prevention and treatment countermeasures of glucocorticoids-induced skin striae distensae. Methods: A case of skin striae distensae caused by glucocorticoids was reported. By searching databases of PubM ed, Medline, China National Knowledge Infrastructure (CNKI) ，Wanfang D at a_D ig it aliz at io n Journals and VIP China Science and Technology Journal Database, relevant literature on glucocorticoids-induced skin striae distensae was ret rived and analyzed, Results : The patient with purpura nephritis was treated with glucocorticoids，and subsequently a large area of striae distensae appeared all over the body, which turned into white striae and did not fade for a long time leaving behind psychological disorder. The analysis results of 83 cases showed that both systemic and local use of glucocorticoids could cause striae distensae and generally appeared within 12-24 weeks after medication. The ratio of male to female was 1 J 1 .44, mostly seen in younsters. Clinical manifestations were mainly purple stripe expansion on the lower abdomen, groin, arms, armpits and other sites, then the purple stripe would turn into white and did not fade for a long time, leaving behind psychological disorder in certain patients. Pathological results showed that the affected epidermis became thinner, elastic fibers broke and collagen decreased, with a mortality rate of 3 .61% and a remission rate of 83.13%. Condlision: Medical personnel should pay close attention to glucocorticoids-induced striae distensae. Once striae distensae developed, it would exist permanently and seriously affect the mental health of patients When necessary, psychological counseling should be implemented to prevent possible psychological disorders. [ABSTRACT FROM AUTHOR]

[Objective] In order to use Phalaenopsis ge mi plasm resourees and perfeet the systematic classification of Phalaenopsis, stomal al characteristics were studied, then the indexes were evaluated by correlation analysis and cluster analysis of Phalaenopsis leaves. [MethodJ 25 cultivars of Phalaenopsis were used as test materials, their 13 stomatal characteristics index (The number of upper epidermis cells, the stomatal number of upper epidermis, the number of lower epidermis cells, the stomatal number of lower epidermis, the stomatal density, the stomatal index, the outer longitudinal diameter, the outer transveise diameter, the inner longitudinal diameter, the inner transveise diameter, the stomatal opening, the stomatal area and the stomatal ratio) were measured and analyzed. [Result] (i) The cell shape of the upper and lower epidermis of the Phalaenopsis leaf was polygonal irregular, and the arrangement of stomata was irregular. (ii) There were significant differences in the stomatal charactal of Phalaenopsis. The stomatal characteristics of 20 Phalaenopsis cultivais were more than that of the lower epidermis, accounting for 80% of the total. No stomatal apparatus was found in the lower epidermis of R7. The outer longitudinal diameter, inner longitudinal diameter, inner transverse diameter, stomatal opening, stomatal area and stomatal ratio of R7 were the smallest a-mong the tested varieties, which were 18.48 mm, 8.3 mm, 9.99 mm, 84.6, 375.92 mm2 and 0.72, respectively. From 0.72 to 1.35, the shape of stomatal oigans of Phalaenopsis species was mainly round or oblate, which was consistent w ith the visual observation. (iii) Correlation analysis showed that there was a high correlation between stomatal indexes of the 13 leaves. (hr) Through the principal component analysis, 13 stomatal characteristics could be synthesized into4 principal components, and the cumulative contribution rate of the fiist four principal components was 91.062%. (v) The result of cluster analvsis showed that 25 Phalaawpsis could be divided into 3 categories at Euclidean distance of 15, category I included 2 species of large flower with purple-red lines, cat eg or)-1(included 1 specie of small flower with purple-red lines, and category III included 22 species of flower with unline or unpuiple-red lines. [Conclusion] The stomatal characteristics could be used as one of the criteria for classification of Phaloenopsis. [ABSTRACT FROM AUTHOR]

The anatomical comparative study of petiole and pinnule cross-sections of nine species from Plagiogyria was performed using light microscopy for the first time. The results showed that the epidermis, the basic tissue and middle column of middle petiole transection and epidermis, mesophyll and main vein of the vegetative leaf pinnule of nine species of Plagiogyria were similar, for example, the epidermis of the transverse section of the middle petiole was not covered with hair or squamas, the epidermis was round in shape with thick-walled tissue, and the central cylinder was a amphicribral vascular bundle; the stomatas of trophyll pinnule transection were only distributed in the lower epidermis, the shape of epidermal cells was flat, and the type of the main vein belongs to the peripheral vascular bundle, which supports for the viewpoint that Plagiogyria was a natural taxonomy. In the evolution of the system, Plagiogyria had a certain relationship with the Alsophila spinulosa and both of them had similar characteristics and also showed certain differences. However, the petiole central transverse section of these nine species of Plagiogyria were trapezoidal, oval or triangular. The shape of the vascular bundle including “U” shape, “V” shape or triangle. The number of vascular bundles in the central transverse section of the petiole was one or three. The arrangement of xylem in vascular bundles including Chinese character “Eight” shape, “U” shape or “-” shape; The underside protuberances of the pinnule main veins were curved, triangular or trapezoidal. The xylem of the petiole had two forms: typical hippocampus and atypical hippocampus. The typical hippocampus was characterized by obvious hook state at both ends of the xylem. The atypical hippocampus was characterized by no obvious hook state at the two ends of xylem or one of the xylems had no hook at one end. These morphological anatomical features are stable and cluster specific, which provides a new reference for taxonomy and systematic studies of Plagiogyria. Finally, a key to the Plagiogyria species is given based on the anatomical characteristics of the transverse section of petiole and pinnule. [ABSTRACT FROM AUTHOR]

Androsace cuscutiformis is reported as a newly recorded species of Primulaceae from Henan. A. cuscutiformis is different from the others species of Androsace in Henan Province with distinctly stolons filiform and lobed leaf blade in the middle. Identification key is provided for Androsace indigenous to Henan Province. The micromorphological characte-ristics of the leaf epidermis and pollen of A. cuscutiformis were observed and described by light microscope(LM)and scanning electron microscope(SEM). The results were as follows both the upper and lower epidermal cells were irregularly polygonal in shape with anticlinal walls sinuate, the lower epidermis had elliptic stomatal apparatus, both the upper and lower epidermis had multicellular hairs with pit sculpture and globular wax, leaf epidermis and types of hair may provide definite reference for the systematic classification and evolution in Androsace; the pollen was elliptic with tricolporate, colpi was narrow, the exine ornamentation of pollen was microechinate without endoaperture, A. cuscutiformis had the smallest pollen in the sect. Samuelia which are different from other groups in Androsace had broad blades, long petioles and dentate or lobed leaf blade. The disjunct distribution of A. cuscutiformis and its relative species A. axillaris and A. geraniifolia and special reproductive mode are likely to indicate that A. cuscutiformis is the relict plant of the primitive group of Androsace in the Funiu Mountain, the southern slope of Qinling Mountains and Daba Mountain. [ABSTRACT FROM AUTHOR]

Objective To observe the efficacy of autologous skin graft combined with allogeneic dermis in the repair of scar contracture deformity at functional site caused by burn. Methods Sixty-nine patients with scar contracture deformity at functional site caused by burn from January to September 2018 were selected. Thirty-six patients underwent autologous thin, medium-thickness and thick skin grafts transplantation after scars resection and release (control group); 33 patients underwent autologous split-thickness skin grafts transplantation combined with allogeneic dermal transplantation (observation group). The clinical efficacy of 3, 6 and 10 months after operation was evaluated by Vancouver Scar Scale (VSS), the wounds of donor sites of skin grafts and the wound healing time of skin grafting area were recorded. Results The VSS scores of observation group at 3, 6 and 10 months after operation were (3.90±0.49), (4.86±0.74) and (5.27± 0.83), which were lower than those before the operation of (13.96±2.39) and the control group of (5.27±0.72), (7.72±0.93) and (8.85±1.19). The difference was statistically significant (P<0.05). The excellent and good rate of the observation group was 54.55% and the control group was 30.56%, the difference was statistically significant (P<0.05). The healing time of donor sites of skin grafts of the observation group was shorter than that of the control group, the VSS scores were lower than those of the control group. The difference was statistically significant (P<0.05). There was no significant difference in healing time of skin grafting area and infection rate between the two groups (P>0.05). Conclusion Autologous skin graft combined with allogeneic dermis can significantly improve local function of scar contracture deformity at functional site after burn, shorten the healing time and reduce the formation of scar in donor sites of skin grafts. [ABSTRACT FROM AUTHOR]

BACKGROUND: Skin-derived precursor cells play a regenerative role in wound healing, which can restore the physiological and aesthetic features of the skin by mitosis, proliferation and migration to the injury region. OBJECTIVE: To observe the structure of the mouse tail and the healing of the broken end, and then to investigate the correlation of these characteristics with the repair of skin trauma at the tail. METHODS: The tails of 2-day-old Kunming mice were cut off using ophthalmic microsurgical scissors to establish the mouse model of hair follicle regeneration in the tail. Regions in which the cells proliferated actively were determined. Wound healing samples were regularly taken, and embedded using OCT. Wound healing of the broken end was routinely observed by pathological staining. Cell proliferation was observed by immunofluorescence. Expression of AP-1 in the healing site was identified by immunofluorescent staining. RESULTS AND CONCLUSION: The structure of the mouse tail was complex, with rich blood supply. Good healing was observed in the broken end of the mouse tail. The cells in the hair follicles and dermal papillary layer showed active proliferation and mitosis, and thereby participated in wound repair and regeneration. Fluorescence staining results found that the positive expression of AP-1 was mainly concentrated in the epidermis and dermal papilla. These findings indicate that the epidermis and dermal papilla possess a strong ability to regenerate. [ABSTRACT FROM AUTHOR]

BACKGROUND: Dermal fibroblasts are widely used and demanded, and there are various isolation methods, but no comparative studies on enzyme digestion methods are reported. OBJECTIVE: To compare the cell count, morphology, migration and proliferation of human dermal fibroblasts isolated by two enzyme digestion methods. METHODS: Human dermal fibroblasts were isolated using either dispase-collagenase or trypsin, and their cell yield and viability were assessed by morphology, cell count and proliferation curve by cell counting-kit 8 assay. The ability of migration was observed by cell scratch test. RESULTS AND CONCLUSION: The fibroblasts digested with dispase-collagenase were fused at 6-7 days after inoculation, and the cells isolated by trypsin digestion were fused at 8-9 days after inoculation. Fibroblasts could be obtained by both two digestion methods. The production in the dispase-collagenase group was significantly higher than that in the trypsin group. The migration rate in the dispase-collagenase group was significantly faster than that in the trypsin group. The growth cures of the human dermal fibroblasts in the two groups revealed that the cell count was positively correlated with time, and the absorbance values of the dermal fibroblasts in the dispase-collagenase group were significantly higher than those in the trypsin group at 3, 4 and 5 days after incubation. To conclude, the cell yields, migration and proliferation of dermal fibroblasts digested with dispase-collagenase are significantly higher than those of the cells digested by trypsin, indicating that dispase-collagenase digestion results in better isolation and viability of dermal fibroblasts from the dermis. [ABSTRACT FROM AUTHOR]

Plagiogyriaceae is a natural fern group with some classification and systmatics controversy because of more morphological differences exist infra and interspecies. The leaf epidermises of ten species of Plagiogyriaceae: Plagiogyria adnata, P. stenoptera, P. falcata, P. assurgens, P. pycnophylla, P. glauca, P. japonica, P. euphlebia, P. matsumureana and P. pectinata, and two species of Cyatheaceae (Alsophila spinulosa and A. khasyana) and one species of Dicksoniaceae (Cibotium barometz) of its related taxa were observed and compared by scanning electron microscope (SEM), and its taxonomical significance was discussed. Hereby, key to ten species tested was also compiled. The stomatal apparatus were oval to circular and restricted in abaxial epidermises for all species. The cuticular membrane of the adaxial leaf epidermis was complicated and some hairs in abaxial epidermis. The patterns of anticlinal walls were depressed. The inner margin of the outer stomatal rim was often sinuous and odontoid, and “T” shape, upright outer stomatal rims occurred in most species. The microcharacters of leaf epidermises can be used as evidence for the classification of the interspecies in Plagiogyriaceae. [ABSTRACT FROM AUTHOR]

BACKGROUND: As a physical factor, negative pressure can promote the osteogenic differentiation and endothelial differentiation of mesenchymal stem cells. If a negative pressure exerts effects on the epidermal differentiation of mesenchymal stem cells, it will be highly important for the combination use of negative pressure and mesenchymal stem cells in wound healing. OBJECTIVE: To explore the effect of negative pressure on the epidermal differentiation of bone marrow mesenchymal stem cells. METHODS: Bone marrow mesenchymal stem cells of New Zealand white rabbits were isolated and cultured. Then, the passage 3 cells were induced for epidermal differentiation under negative pressure (-16.625 kPA, twice a day, once for 4 hours) as experimental group. Another cells induced under no negative pressure were used as control group. After induction, cell growth curve was drawn in each group, and the expression of cytokeratin 5 and cytokeratin 10 mRNA was examined by real-time PCR at 2 weeks after induction. RESULTS AND CONCLUSION: The cell growth of the experimental group was inhibited, and the mRNA expression of cytokeratin 5 and cytokeratin 10 was significantly increased compared with the control group (P < 0.05). These findings indicate that under the condition of negative pressures, the epidermal differentiation ability of bone marrow mesenchymal stem cells is increased, and in contrary, the cell proliferation is inhibited. [ABSTRACT FROM AUTHOR]

Alopecurus was a common and widespread genus of Poaceae subfamily Pooideae. It was common across temperate and cold regions of the north hemisphere, South America. Alopecurus is a genus of eight species distributed in China. They are Alopecurus aequalis, A. japonicus, A. arundinaceus, A. brachystachyus, A. myosuroides, A. longiaristatus, A. longiaristatus, and A. pratensis. A few, particularly Alopecurus aequalis and A. japonicus, were considered weeds, other species were used as fine grasses for animals. It is of great significance to infer systematic relationships among species of Alopecurus. But there are few studies about the leaf morphology of Alopecurus. The micromorphology of leaf abaxial epidermis(including leaf sheath)was observed under light microscope and scanning electron microscope for seven species of Alopecurus occurring in China. The results were as follows:(1)The leaf sheath epidermis of Alopecurus were characterized by long-tubular or short-tubular cells with markedly sinuousness cell walls, elliptic or crescentic short cells distributed solitary or in pairs, elliptic silica bodies, parallel-sided or low dome-shaped subsidiary cells. The morphology of leaf sheath epidermis was highly consistent. The evidences of leaf sheath epidermis made no sense to distinguish species of Alopecurus. There was nearly no significant differences exited at species level.(2)Leaf epidermis structure and leaf epidermis sheath structure were significantly different. The leaf abaxial epidermis of Alopecurus was characterized by long-tubular or short-tubular or rhombic long cells with straight or undulating walls, presence or absence of short cells in intercostal zone, presence of prickles in costal, presence or absence of prickles in intercostal zone, parallel-sided subsidiary cells, horizontally elongated crenate silica-cell in costal zone. Some epidermal features varied in the shape and wall thickness of long cells, presence or absence of short cells, the numbers of prickles in intercostal zones, the rows of stomata. These diversities could provide the evidences for classification of species. A key of the species of the genus Alopecurus on the basis of the leaf morphology was present in the paper. In addition, the type of division on the basis of leaf epidermis morphology was not entirely consistent with sections identified based on external morphology. But due to limited species of the research, the leaf epidermal micromorphology for the significance of Alopecurus's classification still needs further research. [ABSTRACT FROM AUTHOR]