[Research advances on the role of microRNA engineered exosomes in diabetic wounds]

Diabetic wounds are a common complication in patients with diabetes, which is difficult to treat. Current treatment methods for diabetic wounds include debridement, functional dressing coverage, negative pressure therapy, bone cement filling, and skin grafting, etc. MicroRNA (miRNA) engineered exosomes have shown promising potential in diabetic wound repair due to the ability to alleviate inflammation, stimulate angiogenesis, and promote collagen deposition and re-epithelialization. Related researches are being actively carred out. This paper reviews the pathophysiological characteristics of diabetic wounds, the characteristics of miRNA and exosomes, the engineering methods for exosomes loaded with miRNA, and the mechanism of miRNA engineered exosomes in promoting healing of diabetic wounds, aiming to provide a reference basis for the future clinical application of miRNA engineered exosomes in diabetic wounds.

[Clinical application of combination of different types of free perforator flaps in the repair of complex wounds in extremities]

Objective: To investigate the clinical application effects of combination of different types of free perforator flaps in the repair of complex wounds in extremities. Methods: A retrospective observational study was conducted. From January 2018 to June 2022, 11 patients with complex wounds in extremities who met the inclusion criteria was admitted to the Affiliated Hospital of Zunyi Medical University, including 8 males and 3 females, aged 28 to 55 years. The wounds in the upper extremities in 4 cases and in the lower extremities in 7 cases were repaired with different combination of free perforator flaps. After debridement, the wound area was 7.0 cm×6.0 cm-28.0 cm×12.0 cm. A combination of different types of perforator flaps were applied, including the perforator tri-leaf flap of the descending branch of the lateral femoral circumflex artery in 6 cases, the descending branch of lateral femoral circumflex artery combined with oblique branch perforating branch flap in 2 cases, the lobulated flap of the descending branch of the lateral femoral circumflex artery combined with the contralateral medial plantar artery perforator flap in 2 cases, and the bilateral perforator flap of the descending branch of lateral femoral circumflex artery combined with great toe nail flap in 1 case, with the size of a single flap ranged from 2.0 cm×2.0 cm-25.0 cm×6.0 cm. The donor site was repaired by direct suture, skin grafting, or flap transplantation. During free flap transplantation, the flap was cut and split according to the distribution of perforators, and end-to-end or end-to-side anastomosis was performed between the donor area and the recipient area. After surgery, the survival of transplanted flap in the primary recipient site, the occurrence of vascular crisis, the wound healing in the flap donor site, and the survival of transplanted skin or flap in the flap donor site were observed. During follow-up, the blood supply, appearance and texture of the transplanted flap in the primary recipient site were observed; and at the same time, the weight bearing of the plantar receiving area, the presence of sliding, ulcers, and sinus tracts of the flap, and the appearance and function of the hand were observed; the complications in the donor area were observed. Results: After surgery, one patient's transplanted flap in the primary recipient site had vascular crisis but survived after exploration+vein graft bridging; partial necrosis occurred in one lobe of anterolateral thigh lobulated flap transplanted to the primary recipient site in one patient and recovered after dressing change+skin grafting, and the different types of perforator flap transplanted to the primary recipient site in the other 9 patients all survived. After surgery, the wound with direct suture at the donor site healed well, and the skin or flap transplanted to the donor area survived well. During 3-24 months of follow-up, the blood supply, appearance, and texture of the transplanted flap at the primary recipient site were good. In two patients, the anterolateral thigh flap combined with the medial plantar flap were used to repair plantar defects. The plantar receiving area was able to bear weight, and the texture of the flaps in the recipient area was close to the normal plantar skin, without flap sliding, ulcer, or sinus tract formation. In one patient, bilateral anterolateral thigh flap combined with great toe nail flap were used to repair hand combined with soft forearm defect, and the appearance and function of hand, especially thumb were good. Only linear scar was left in the donor site without other obvious complications. Conclusions: The combination of different types of perforator flaps is a reliable clinical method to repair complex wounds in extremities with high safety, good efficacy, and less complications.

[Clinical effects of antibiotic bone cement combined with free anterolateral thigh flap in sequential treatment of diabetic foot ulcer]

Objective: To investigate the clinical effects of antibiotic bone cement combined with free anterolateral thigh flap in sequential treatment of diabetic foot ulcer (DFU) wounds. Methods: A retrospective observational study was conducted. From August 2018 to August 2021, 15 patients with DFU who met the inclusion criteria were admitted to the Affiliated Hospital of Zunyi Medical University, including 12 males and 3 females, aged 42-65 years, with a history of type 2 diabetes for 5-19 years. All the wounds of patients were complicated with local bone, muscle, or tendon defects or exposure. The wounds were covered with antibiotic bone cement after debridement in stage Ⅰ+free anterolateral thigh chimeric perforator flap (perforator flap+muscle flap) or simple free anterolateral thigh flap grafting in stage Ⅱ. The defect area of the wound after bone cement removal and debridement was 9.0 cm×5.0 cm-20.0 cm×7.0 cm, the incision area of the flap was 10.0 cm×5.0 cm-22.0 cm×7.0 cm, and the incision area of the muscle flap was 5.0 cm×3.0 cm-8.0 cm×4.0 cm. The donor sites of flaps were sutured directly. During follow-up, the situations of donor site healing and flap survival were observed. At the last follow-up, the texture and shape of the flap, the presence of new ulcers on both limbs, and the walking ability of the patient were observed. Results: During the follow-up of 8 to 21 months after operation in stage Ⅱ, the donor sites healed well with only residual linear scar; flaps in 14 patients survived completely, and the flap in 1 patient developed partial necrosis at 3 weeks after stage Ⅱ surgery, which was healed after debridement and skin grafting. At the last follow-up, the flaps were good in texture and appearance, there were no new ulcers in the affected limb or opposite limb, and the patients had no obvious impairment in daily walking function. Conclusions: To repair DFU wounds with antibiotic bone cement combined with free anterolateral thigh flap can rapidly control the infection, achieving a high survival rate of flap after operation with no obvious impairment in daily walking function of patients.

[Research advances on mesenchymal stem cells and their derivatives in the treatment of acne scars]

Acne is a common chronic inflammatory disease of the skin that often occurs on the face, and acne scars are often secondary to the healing process of acne, which often leads to impaired appearance and psychological disorders of patients. The current treatment for acne scars is extremely difficult. With the development of regenerative medicine, stem cell transplantation has become a new treatment for acne scars. In recent years, it has been reported that stem cells and their derivatives can effectively antagonize the formation of acne scars. Therefore, this paper briefly reviews the basic and clinical researches on the treatment of acne scars with various mesenchymal stem cells and their derivatives, aiming to provide theoretical basis and reference for the stem cell therapy of acne scars.

[Clinical application effects of two longitudes three transverses method in perforator location of thoracodorsal artery perforator flap and deep wound repair]

Objective: To explore the clinical application value of two longitudes three transverses method in the location of the perforator of thoracodorsal artery perforator and deep wound repair. Methods: The retrospectively observational study was conducted. From December 2018 to June 2020, 17 patients with deep wounds who were admitted to the Affiliated Hospital of Zunyi Medical University met the inclusion criteria and were included in this study, including 7 males and 10 females, aged 12 to 72 years. The wound areas of patients after debridement were 7 cm×3 cm to 11 cm×7 cm. Two longitudinal lines were located through the midpoint of the armpit, the posterior superior iliac spine, and the protruding point of the sacroiliac joint, and three transverse lines were located 5, 10, and 15 cm below the midpoint of the armpit between the two longitudinal lines, i.e. two longitudes three transverses method, resulting in two trapezoidal areas. And then the thoracodorsal artery perforators in two trapezoidal areas were explored by the portable Doppler blood flow detector. On this account, a single or lobulated free thoracodorsal artery perforator flap or flap that carrying partial latissimus dorsi muscle, with an area of 7 cm×4 cm to 12 cm×8 cm was designed and harvested to repair the wound. The donor sites were all closed by suturing directly. The number and location of thoracodorsal artery perforators, and the distance from the position where the first perforator (the perforator closest to the axillary apex) exits the muscle to the lateral border of the latissimus dorsi in preoperative localization and intraoperative exploration, the diameter of thoracodorsal artery perforator measured during operation, and the flap types were recorded. The survivals of flaps and appearances of donor sites were followed up. Results: The number and location of thoracodorsal artery perforators located before operation in each patient were consistent with the results of intraoperative exploration. A total of 42 perforators were found in two trapezoidal areas, with 2 or 3 perforators each patient. The perforators were all located in two trapezoid areas, and a stable perforator (the first perforator) was located and detected in the first trapezoidal area. There were averagely 1.47 perforators in the second trapezoidal area. The position where the first perforator exits the muscle was 2.1-3.1 cm away from the lateral border of the latissimus dorsi. The diameters of thoracodorsal artery perforators were 0.4-0.6 mm. In this group, 12 cases were repaired with single thoracodorsal artery perforator flap, 3 cases with lobulated thoracodorsal artery perforator flap, and 2 cases with thoracodorsal artery perforator flap carrying partial latissimus dorsi muscle. The patients were followed up for 6 to 16 months. All the 17 flaps survived with good elasticity, blood circulation, and soft texture. Only linear scar was left in the donor area. Conclusions: The two longitudes three transverses method is helpful to locate the perforator of thoracodorsal artery perforator flap. The method is simple and reliable. The thoracodorsal artery perforator flap designed and harvested based on this method has good clinical effects in repairing deep wound, with minimal donor site damage.

[Research on feasibility of in vitro inflammatory wound microenvironment simulated by using inflammatory wound tissue homogenate of mice]

Objective: To investigate the feasibility of in vitro inflammatory wound microenvironment simulated by using inflammatory wound tissue homogenate of mice. Methods: (1) Ten eight-week-old C57BL/6 male mice were collected and full-thickness skin tissue with diameter of 1.0 cm on both sides of the midline of the back was taken with a perforator to make the normal skin tissue homogenate supernatant. At 48 h after the full-thickness skin defect wound was established, the wound tissue within 2 mm from the wound edge was taken to make inflammatory wound tissue homogenate supernatant. Two kinds of tissue homogenate supernatant were taken to adjust the total protein concentration to 1 mg/mL, and the tumor necrosis factor α (TNF-α) content was detected by enzyme-linked immunosorbent assay. The number of sample was 6. (2) The primary passage of human umbilical cord mesenchymal stem cells (hUCMSCs) were collected and cultured to the 3rd passage with the normal exosomes being extracted from the hUCMSCs after cultured for 48 h. Another batch of hUCMSCs in the 3rd passage was collected and stimulated with inflammatory wound tissue homogenate supernatant of 30, 50, and 100 μg/mL total protein and normal skin tissue homogenate supernatant of 30, 50, and 100 μg/mL total protein, respectively. After cultured for 48 h, the exosomes stimulated with normal protein of 30, 50, and 100 μg/mL and exosomes stimulated with inflammatory protein of 30, 50, and 100 μg/mL were extracted. Normal exosomes, exosomes stimulated with 30 μg/mL normal protein, and exosomes stimulated with 30 μg/mL inflammatory protein were collected, the morphology was observed by transmission electron microscope, the particle size was detected by nanoparticle tracking analyzer, and the expressions of CD9 and CD63 were detected by Western blotting. (3) Twenty one-day-old C57BL/6 mice were taken to isolate the primary passage of fibroblasts (Fbs) and the 3rd passage of Fbs, whose morphology was observed under the inverted phase contrast microscope. The Fbs of 3rd passage were collected to observe the expression of vimentin by cell crawling method combined with immunofluorescence method at culture hour (CH) 2. (4) The Fbs of 3rd passage were divided into control group, normal exosome group, 30, 50, 100 μg/mL normal protein stimulating exosome group, and 30, 50, 100 μg/mL inflammatory protein stimulating exosome group according to the random number table, with 4 wells in each group. Cells in control group received no treatment, and cells in the other 7 groups were respectively added with normal exosomes, exosomes stimulated with normal protein of 30, 50, and 100 μg/mL, and exosomes stimulated with inflammatory protein of 30, 50, and 100 μg/mL prepared in experiment (2). The final mass concentration of exosomes was adjusted to 10 μg/mL. The cell viability was detected by cell count kit 8 at CH 48. (5) Two batches of Fbs in the 3rd passage were divided and treated as those in experiment (4), with 4 wells in each group, and the final mass concentration of exosomes was adjusted to 1 and 10 μg/mL, respectively. The cell mobility was detected by cell scratch test at CH 6, 12, and 24. (6) Two batches of the Fbs of 3rd passage were collected, divided, and treated as those in experiment (4) except with no control group, with 3 wells in each group, and the final mass concentration of exosomes was respectively adjusted to 1 and 10 μg/mL. The mRNA expression levels of transforming growth factor β(1) (TGF-β(1)), TGF-β(3), and α smooth muscle actin (α-SMA) were detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction at CH 48. Data were statistically analyzed with analysis of variance for repeated measurement, one-way analysis of variance, and Bonferroni method. Results: (1) The content of TNF-α in inflammatory wound tissue homogenate supernatant of mice was (116±3) pg/mL, significantly higher than (97±5) pg/mL in normal skin tissue homogenate supernatant at post injury hour 48 (t=3.306, P<0.05). (2) Normal exosomes, exosomes stimulated with 30 μg/mL normal protein, and exosomes stimulated with 30 μg/mL inflammatory protein of hUCMSCs showed the typical saucer-like shape. The particle sizes of the three exosomes of hUCMSCs were 30-150 nm, which were all within the normal particle size range of exosome. Three exosomes of hUCMSCs positively expressed CD9 and CD63. (3) The primary passage of cells were clearly defined and showed protruding spindle shape, irregular polygon shape, or slender strip shape. The morphology of the 3rd and the primary passage of cells is similar. At CH 2, vimentin in cells was positively expressed, and the cells were identified as Fbs. (4) At CH 48, the cell viability was (137.4±2.8)% in 30 μg/mL inflammatory protein stimulating exosome group, obviously higher than 100%, (107.5±2.4)%, (113.3±3.2)%, (104.0±2.0)%, and (101.9±1.5)% in control group, normal exosome group, 30 μg/mL normal protein stimulating exosome group, and 50 and 100 μg/mL inflammatory protein stimulating exosome groups, respectively (P<0.01), and cell viability in 30 μg/mL normal protein stimulating exosome group was obviously higher than that in control group, normal exosome group, and 50 and 100 μg/mL normal protein stimulating exosome groups [(103.4±2.2)% and (102.5±1.4)%], respectively (P<0.01). (5) At CH 6, 12, and 24, the mobility rate of cells in 30 μg/mL inflammatory protein stimulating exosome group was significantly higher than that in control group, normal exosome group, 30 μg/mL normal protein stimulating exosome group, and 50 and 100 μg/mL inflammatory protein stimulating exosome groups, respectively, when the final mass concentrations of exosome was 1 μg/mL (P<0.05) . At CH 12, the mobility rate of cells in 30 μg/mL normal protein stimulating exosome group was obviously higher than that in control group, normal exosome group, and 50 and 100 μg/mL normal protein stimulating exosome groups, respectively, when the final mass concentration of exosome was 1 μg/mL (P<0.05). At CH 6, the mobility rate of cells in 30 μg/mL inflammatory protein stimulating exosome group was significantly higher than that in control group and normal exosome group (P<0.05), and the mobility rate of cells in 30 μg/mL normal protein stimulating exosome group was significantly higher than that in 50 and 100 μg/mL normal protein stimulating exosome groups, respectively, when the final mass concentration of exosome was 10 μg/mL (P<0.05). At CH 12 and 24, the mobility rate of cells in 30 μg/mL inflammatory protein stimulating exosome group was significantly higher than that in control group, normal exosome group, and 50 and 100 μg/mL inflammatory protein stimulating exosome groups (P<0.05), and the mobility rate of cells in 30 μg/mL normal protein stimulating exosome group was significantly higher than that in control group, normal exosome group, and 50 and 100 μg/mL normal protein stimulating exosome groups, respectively, when the final mass concentration of exosome was 10 μg/mL (P<0.05). (6) There were no statistically significant differences in mRNA expression levels of TGF-β(1), TGF-β(3), and α-SMA of cells among the 7 groups at CH 48 when the final mass concentration of exosome was 1 μg/mL (F=1.123, 1.537, 1.653, P>0.05). There were no statistically significant differences in mRNA expression levels of TGF-β(1) and α-SMA of cells among the 7 groups at CH 48 when the final mass concentration of exosome was 10 μg/mL (F=1.487, 1.308, P>0.05), and mRNA expression level of TGF-β(3) of cells in 50 μg/mL inflammatory protein stimulating exosome group at CH 48 was significantly higher than that in normal exosome group, 50 μg/mL normal protein stimulating exosome group, and 30 and 100 μg/mL inflammatory protein stimulating exosome groups when the final mass concentration of exosome was 10 μg/mL (P<0.05). Conclusions: The pretreatment with inflammatory wound tissue homogenate supernatant of mice has no significant effect on the total protein of hUCMSCs exosomes. The hUCMSCs exosomes stimulated by low concentration inflammatory wound tissue homogenate supernatant can significantly promote the proliferation and migration ability of Fbs. The content of inflammatory mediators in the wound tissue homogenate supernatant during the inflammatory phase is extremely low, which may be the reason that the anti-inflammation and tissue repair paracrine effects of mesenchymal stem cell cannot be effectively started.

[Clinical effects of modified fascia flap from cutaneous branch of dorsal metacarpal artery in repairing the wound at the proximal and middle finger segments]

Objective: To investigate the clinical effects of modified fascia flap from cutaneous branch of dorsal metacarpal artery in repairing the wound at the proximal and middle finger segments. Methods: From January 2017 to September 2018, 12 patients with wounds at the proximal and middle finger segments were admitted to the Affiliated Hospital of Zunyi Medical University, including 8 males and 4 females, aged 35-70 years. The areas of wounds ranged from 3.4 cm×2.4 cm to 6.5 cm×4.0 cm. The modified fascia flaps from cutaneous branch of dorsal metacarpal artery were resected to repair the wounds, with the size ranging from 3.5 cm×2.5 cm to 6.7 cm×4.1 cm. The flap donor sites of 5 patients were repaired with direct intermittent suture, the flap donor sites of 4 patients were repaired with full-thickness skin grafts from ipsilateral medial forearm, and the flap donor sites of 3 patients were repaired with wrist pedicled flaps. The survival of the flaps was recorded. Healing of donor site and recipient site was followed. The hand functions were evaluated with trial standard for the evaluation of the functions of the upper limbs of the Hand Surgery Society of the Chinese Medical Association. Results: All the flaps survived in 12 cases. During 3 to 12 months of follow-up, the flaps recovered satisfactorily in texture and shape. The donor sites of 11 patients were healed, and the skin graft edge area was partially necrotic in the other patient but healed later after dressing change. The distances of two-point discrimination of the patients ranged from 5.6 to 9.0 mm. Hand functions were evaluated as excellent in 5 cases, good in 4 cases, and fair in 3 cases. Conclusions: Modified fascia flap from cutaneous branch of dorsal metacarpal artery for repairing the wounds at the proximal and middle finger segments has reliable blood supply. The operation is simple and safe with short course of treatment, which is worthy of clinical promotion.

[Advances in the research of effects of epithelial-mesenchymal interaction on wound healing and scar formation]

Wound healing is a dynamic process which involves interaction of various types of cells, cytokines, and extracellular matrix. Among them, epithelial cells and mesenchymal cells are the key components which involve in wound healing and scar formation. Related scholars had done a great number of studies about the functions of epithelial cells and fibroblasts(Fbs) in wound healing and scar formation. The results showed that under the stimulation of complex microenvironment, epithelial cells would lose their epithelial characteristics and acquire the typical characteristics and migration ability of mesenchymal cells. At the same time, with the complex changes of cell structure and cell behavior, they would participate in the process of tissue wound repair, including normal or fibrotic repair, by covering the wound with migration. Fbs are the key cells for the wound fibrotic repair, and play important roles in the process of wound healing, including excessive wound healing or delayed wound healing. In the recent years, the researchers realized that the cross-talk between epithelial cells and Fbs in wound healing, which is referred to as epithelial-mesenchymal interaction, significantly changes the biological behaviors of these two cell types, which affects the dermal remodeling and re-epithelialization quality of wound. Epithelial-mesenchymal interaction plays an important role in skin morphogenesis during embryonic development and maintaining the structural integrity of adult skin. In the process of re-epithelialization, Fbs could promote the proliferation and migration of keratinocytes, meanwhile keratinocytes would receive the signals from Fbs to reconstruct functional epithelium, which has become a hot topic in the field of wound healing at present. In this paper, a comprehensive analysis of the literature on the role of epithelial-mesenchymal interaction in wound healing and scar formation at home and abroad in recent years is presented for the reference of relevant scholars.

[Influence of human amniotic mesenchymal stem cells on macrophage phenotypes and inflammatory factors in full-thickness skin wounds of mice]

Objective: To explore the influence of human amniotic mesenchymal stem cells (hAMSCs) on the in vivo and in vitro regulation of macrophage phenotypes and inflammatory factors associated with wound healing of full-thickness skin wounds in mice. Methods: Fresh amniotic membrane discarded from full-term delivery by 5 healthy pregnant women in the Department of Obstetrics and Gynecology of the Affiliated Hospital of Zunyi Medical University was used for the isolation and culture of hAMSCs by enzyme digestion method. The third passage of cells was used for identification of adipogenic and osteogenic differentiation. The fourth passage of cells was used for identification of hAMSCs surface markers. Ten C57BL/6 mice (all male, aged 6 to 8 weeks, the same gender and age below) were selected for extracting mouse peritoneal macrophages by intraperitoneal lavage, and M1-type macrophages were induced by Dulbecco's modified eagle medium (DMEM) medium containing interferon-γ. The M1-type macrophages were divided into hAMSCs+ macrophage group and macrophage alone group. Then 1×10(4) hAMSCs/per well of fourth passage were added to macrophage in hAMSCs+ macrophage group and cultured in 2 mL DMEM medium for routine culture. In macrophage alone group, each well was only added with 2 mL DMEM medium for routine culture. On day 1 and 7 in culture, the content of interleukin-12 (IL-12), arginase 1, and IL-10 in the cell culture supernatant of the 2 groups were detected by enzyme-linked immunosorbent assay with sample number of 6/per group. (2) Full-thickness skin wound model was reproduced in the back of 56 C57BL/6 mice, which were divided into hAMSCs group and phosphate buffer solution (PBS) group using the random number table, with 28 mice in each group. Mice in hAMSCs group were subcutaneously injected with 100 μL of cell suspension containing 1×10(7) hAMSCs per mL in PBS suspension along the wound edge. While mice in PBS group were only subcutaneously injected with 100 μL PBS along the wound edge. On post injection day (PID) 1, 3, 7, and 14, 7 mice in the two groups were sacrificed respectively. Histopathological observation was performed with hematoxylin-eosin staining. The expressions of macrophage surface markers [CD68 and inducible nitric oxide synthase (iNOS) double positive cells and CD68 and arginase 1 double positive] in the wounds were detected by immunofluorescent staining. The mRNA expressions of IL-10, macrophage inflammatory protein 1α (MIP-1α), and MIP-2 in the wounds were detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction. Data were statistically analyzed with analysis of variance for factorial design, t test, and Bonferroni correction. Results: (1) On day 1 in culture, the content of IL-12 and arginase 1 in the cell culture supernatant of the two groups were similar (t=0.448, 0.536, P>0.05), and the content of IL-10 in the cell culture supernatant of hAMSCs+ macrophage group was significantly lower than that in macrophage alone group (t=14.722, P<0.01). On day 7 in culture, the content of IL-12 in the cell culture supernatant of hAMSCs+ macrophage group was significantly lower than that in macrophage alone group (t=13.226, P<0.01), and the content of arginase 1 and IL-10 was significantly higher than that in macrophage alone group (t=30.172, 31.406, P<0.01). (2) On PID 1, a large number of inflammatory cells infiltration were observed in the skin wounds of both groups. On PID 3, the inflammatory cells infiltration in the skin wounds increased in both groups, and the inflammatory cells infiltration in hAMSCs group was less than that in the PBS group. On PID 7, the inflammatory cells infiltration in the wounds decreased in both groups, and the inflammatory cells infiltration in hAMSCs group was less than that in the PBS group. On PID 14, no obvious inflammatory cells infiltration was observed in the wounds in the two groups. (3) On PID 1 and 14, the percentages of CD68 and iNOS double positive cells and CD68 and arginase 1 double positive cells in the wounds were similar in the two groups (t(1 d)=0.134, 0.693, t(14 d)=1.146, 2.585, P>0.05). On PID 3 and 7, the percentages of CD68 and iNOS double positive cells in the wounds in hAMSCs group were significantly lower than those of PBS group (t=6.396, 4.787, P<0.01), while the percentages of CD68 and arginase 1 double positive cells were significantly higher than those of PBS group (t=3.928, 4.473, P<0.01). (4) On PID 1, the mRNA expressions of IL-10 in the wounds of mice in the two groups were similar (t=2.005, P>0.05). On PID 3, 7, and 14, the mRNA expressions of IL-10 in the wounds of mice in hAMSCs group were significantly higher than those of PBS group (t=7.758, 124.355, 80.823, P<0.01). On PID 1, 3, 7, and 14, the mRNA expressions of MIP-1α and MIP-2 in the wounds of mice in hAMSCs group (0.341±0.212, 0.648±0.004, 0.611±0.106, 0.763±0.049, 1.377±0.099, 1.841±0.042, 1.181±0.035, 0.553±0.028) were significantly lower than those of PBS group (3.853±0.035, 6.914±0.163, 3.648±0.113, 2.250±0.046, 11.119±0.495, 8.634±0.092, 5.722±0.021, 4.862±0.036, t=43.198, 101.904, 51.845, 58.231, 51.074, 177.501, 291.752, 251.614, P<0.01). Conclusions: hAMSCs demonstrates biological effects of promoting the transformation of M1-type macrophages into M2-type macrophages in full-thickness skin wounds of mice. They can up-regulate the expression of anti-inflammatory and anti-fibrotic factor IL-10, and down-regulate the expression of important inflammation mediated factors MIP-1α and MIP-2.

[Effects of local transplantation of autologous adipose-derived stromal vascular fraction on the hyperplastic scar formation in rabbit ears and the mechanism]

Objective: To explore the effects of local transplantation of autologous adipose-derived stromal vascular fraction (SVF) on the hyperplastic scar (HS) formation in rabbit ears and the mechanism. Methods: Twenty-four New Zealand white rabbits were used to reproduce HSs by making four full-thickness skin defect wounds with a diameter of 1 cm on the ventral surface of left ear of each rabbit. Wound epithelization and local-tissue proliferation were observed, and wound healing (complete epithelization) time and formation time of HS were recorded. The 24 rabbits were divided into SVF group, pure DMEM group, and pure HS group according to the random number table, with 8 rabbits and 32 wounds in each group. On post injury day (PID) 25 (after the complete epithelization of wounds), 0.2 mL of low glucose DMEM medium containing CM-Dil labeled autologous SVF was injected into HSs of rabbits in SVF group, while the same amount of low glucose DMEM medium was injected into HSs of rabbits in pure DMEM group. The frequency of injection was once every 5 days, totally for 3 times. HSs of rabbits in pure HS group did not receive any treatment. On PID 40, HSs of rabbits' ears in each group were harvested, then the histological form was observed by hematoxylin and eosin staining, the arrangement of collagen in HS was observed by Van Gieson staining, the distribution of CM-Dil-labeled SVF in the HS was observed with fluorescence microscope, and the mRNA expression and the protein expression of transforming growth factor β(1) (TGF-β(1)), Smad3, and Smad7 in HS were determined by real-time fluorescent quantitative reverse transcription-polymerase chain reaction and Western blotting, respectively. Data were processed with one-way analysis of variance and Tukey test. Results: (1) Complete epithelization time of wounds of rabbits' ears was (20.0±2.0) d post injury, and HSs were formed on PID 25. On PID 40, HSs of rabbits' ears in pure DMEM group and pure HS group were still in hyperplasia, while those in SVF group became smaller, flat, soft, and light colored. (2) On PID 40, compared with those in pure DMEM group and pure HS group, the number of epithelium foot like structures was more and the amount of inflammatory cells was less. The collagen of HSs of rabbits' ears in SVF group was arranged more regularly with broader gap between collagens. (3) On PID 40, CM-Dil-labeled SVF could still be observed in the HSs of rabbits' ears in SVF group. (4) On PID 40, compared with those in pure DMEM group and pure HS group, the mRNA expressions of TGF-β(1) and Smad3 in the HSs of rabbits' ears in SVF group were significantly down-regulated (P<0.05), while the mRNA expression of Smad7 was significantly up-regulated (P<0.05). There were no significant differences in the mRNA expressions of TGF-β(1), Smad3, and Smad7 in the HSs of rabbits' ears between pure DMEM group and pure HS group (P>0.05). (5) On PID 40, compared with those in pure DMEM group (0.74±0.03, 0.73±0.10, 0.54±0.09) and pure HS group (0.72±0.08, 0.71±0.12, 0.53±0.06), the protein expressions of TGF-β(1) and Smad3 in the HSs of rabbits' ears in SVF group (0.57±0.06, 0.42±0.09) were significantly down-regulated (P<0.05), while the protein expression of Smad7 (0.71±0.05) was significantly up-regulated (P<0.05). The protein expressions of TGF-β(1), Smad3, and Smad7 in the HSs of rabbits' ears in pure DMEM group and pure HS group were close (P>0.05). Conclusions: Autologous SVF transplantation can inhibit the formation of HS in the early stage of scar formation of rabbit, the mechanism may be related to the TGF-β(1)/Smad signaling pathway.

The Influence of Surface Bioactivated Modification on Titanium Percutaneous Implants Anchored in Bone

In order to achieve biological sealing and resist mechanical damage of load-bearing percutaneous devices, Ti with excellent mechanical properties was anodic-oxidized to be endowed with bioactivity, with plasma-sprayed hydroxyapatite coated Ti as control. Similar to previous works, hydroxyapatite coating could bond tightly with living tissues, resulting in implant stability for whole implantation periods. Meanwhile, when anodic-oxidized bioactivated Ti was implanted percutaneously in vivo, it could induce a layer of calcium phosphate at the interface of tissues/implant. This layer of Ca-P not only induced the fibrous tissue or collagen ingrowth in its structure, but also improved the osteointegration between the bone and the implant. There was no significant biological response difference for the anodic-oxidized Ti and HA coated Ti at different implantation period with histological statistical analysis (p>0.05). Accordingly, suitable bioactivated modified surface of Ti by anodic-oxidized method could not only obtain the same results as the HA coating, but also might avoid some drawbacks of plasma-sprayed HA coatings to achieve biological sealing for a long period in vivo.

SRAP analysis of DNA base sequence changes in lotus mutants induced by Fe⁺ implantation

Ion implantation, a new biophysically mutagenic technique, has shown great potential for crop breeding. To reveal the mutation effect of low-energy ion implantation on Baiyangdian red lotus, sequence-related amplified polymorphism markers were used to amplify and detect the DNA sequence differences in mutants induced by Fe(+) ion implantation. A total of 121 primer combinations were tested in 6 mutants and a control. Seven primer combinations (me1 + em3, me1 + em14, me9 + em3, me8 + em2, me6 + em1, me11 + em5, and me6 + em5) generated clear bands with high polymorphism and good repeatability. The results showed that among 15,317 bases cloned, 146 bases in 6 mutants were different from those of the wild type, showing a variation frequency of 0.95%. The types of base changes included deletion, insertion, transversion, and transition. Adenine was more sensitive to the irradiation than were the other bases. The results suggested that mutational "hotspots" probably exists in lotus and are induced by low-energy ion implantation.

First Report of Cherry necrotic rusty mottle virus on Stone Fruit Trees in China

During the growing seasons of 2010 through 2012, leaf tissues from 206 stone fruit trees, including one flowering cherry, three sour cherry, six nectarine (Prunus persica L. var. nucipersica Schneider), 14 apricot, 24 plum (P. domestica L.), 41 sweet cherry, and 117 peach [P. persica (L.) Batsch] trees, grown in six provinces of China, were randomly collected and tested for the CNRMV infection by RT-PCR. Out of those sampled trees, 37 showed shot holes and vein yellowing symptoms. Total RNA was extracted from leaves using the CTAB protocol reported by Li et al. (2). The primer pair CGRMV1/CGRMV2 (1) was used to amplify a fragment of 949 bp from CNRMV genome, which includes the CP gene (804 bp). PCR products with the expected size were detected in one sweet cherry, one apricot, one peach, one plum, and two sour cherry plants. However, no correlation between PCR data and symptom expression could be found. PCR products were cloned into the vector pMD18-T (TaKaRa, Dalian, China). Three independent clones from each isolate were sequenced by Genscript Corp., Nanjing, China, and sequences were deposited in the GenBank under accession nos. JX491635, JX491636, JX491637, JX648205, and JX648206. Results of sequence analysis showed that sequences of the five CNRMV isolates shared the highest nt (99.0 to 99.6%) and aa (98.9 to 100%) similarities with a cherry isolate from Germany (GenBank Accession No. AF237816). The sequence of one isolate from a peach tree (JX648205) was divergent and shared only 84.7 to 86.1% nt and 94.4 to 95.1% aa similarities with those cp sequences. Clones intra each isolate shared more than 99% nt similarities. To confirm CNRMV infection, seedlings of peach GF 305 were graft-inoculated with bud-woods from a peach and a sweet cherry tree, which was positive to CNRMV and also two other viruses: Cherry green ring mottle virus (CGRMV) and Plum bark necrosis stem pitting-associated virus (PBNSPaV), as tested by RT-PCR. Grafted seedlings were kept in an insectproof greenhouse and observed for symptom development. In May of the following year, some newly developed leaves of inoculated seedlings showed vein yellowing, ringspot, and shot hole symptoms. Results of Protein A sandwich (PAS)-ELISA using an antiserum raised against the recombinant CP of a CNRMV isolate (unpublished) and RT-PCR confirmed CNRMV infection in inoculated trees. In addition to CNRMV, tested seedlings were also found to be infected with CGRMV and PBNSPaV by RT-PCR. To our knowledge, this is the first report on the occurrence of CNRMV on stone fruit trees in China, and also the first record of the CNRMV infection in peach and plum plants. Given the economic importance of its hosts and the visible symptoms of the viral disease, it is important to prevent the virus spread by using virus-tested propagation materials. References: (1) R. Li and R. Mock. J. Virol. Methods 129:162, 2005. (2) R. Li et al. J. Virol. Methods 154:48, 2008.

The point mutation induced by the low-energy N+ ion implantation in impatiens balsamine genome

To investigate the effect of genome mutations induced by low energy ions implantation in higher plants, genome mutation of Impatiens balsamine mutant induced by low energy N+ ion implantation were analyzed by the RAPD, ISSR and genome sequence. Six out of the 121 ISSR primers and 6 out of the 135 RAPD primers showed that polymorphism ratios between mutants and wild type were 4.96% and 2.89%, respectively. Sequence analysis revealed that base deletions, insertions, and substitutions were observed in the mutant genome comparable to wild type. N+ induced point mutations were mostly base substitution (77.4%), no duplication, long fragments insertions and deletions was found. In all point mutation, adenine (A) was most sensitive to the N+ ion implantation in impatiens. The transition was mainly A --> guanine (G) (15.90%) and thymine (T) --> cytosine (C) (12.55%). Transversion happened in A <--> T (16.74%), which much higher than C <--> G(5.02%), G <--> T(6.69%), A <--> C (7.11%) bases. These findings indicate that low energy ions being a useful mutagen were mostly cause the point mutation in impatiens.

Early evidence of the genus Homo in East Asia

The timing and route of the earliest dispersal from Africa to Eastern Asia are contentious topics in the study of early human evolution because Asian hominin fossil sites with precise age constraints are very limited. Here we report new high-resolution magnetostratigraphic results that place stringent age controls on excavated hominin incisors and stone tools from the Yuanmou Basin, southwest China. The hominin-bearing layer resides in a reverse polarity magnetozone just above the upper boundary of the Olduvai subchron, yielding an estimated age of 1.7Ma. The finding represents the age of the earliest documented presence of Homo, with affinities to Homo erectus, in mainland East Asia. This age estimate is roughly the same as for H. erectus in island Southeast Asia and immediately prior to the oldest archaeological evidence in northeast Asia. Mammalian fauna and pollen obtained directly from the hominin site indicate that the Yuanmou hominins lived in a varied habitat of open vegetation with patches of bushland and forest on an alluvial fan close to a lake or swamp. The age and location are consistent with a rapid southern migration route of initial hominin populations into Eastern Asia.

The genomic sequence and biological properties of Pennisetum mosaic virus, a novel monocot-infecting potyvirus

The complete nucleotide sequences of two isolates of Pennisetum mosaic virus (PenMV) were determined. The viral genome comprised 9,611 nucleotides (nt) excluding the 3'-terminal poly(A) sequence, with the capacity of encoding a single polyprotein of 3,065 amino acids. The large open reading frame is flanked by a 172-nt 5'-untranslated region (UTR) and a 244-nt 3'-UTR. Sequence comparisons and phylogenetic analyses of the complete genome and polyproteins suggest that PenMV is closely related to other monocot potyviruses such as Maize dwarf mosaic virus, Sorghum mosaic virus and Sugarcane mosaic virus (SCMV), and thus represents a distinct potyvirus within the SCMV subgroup. The host range of PenMV is limited to Gramineae, and the virus naturally infects maize, sorghum and some wild grasses, causing mosaic symptoms on the leaves. This virus could be transmitted by both mechanical inoculation and by at least four species of aphids.

New evidence on the earliest human presence at high northern latitudes in northeast Asia

The timing of early human dispersal to Asia is a central issue in the study of human evolution. Excavations in predominantly lacustrine sediments at Majuangou, Nihewan basin, north China, uncovered four layers of indisputable hominin stone tools. Here we report magnetostratigraphic results that constrain the age of the four artefact layers to an interval of nearly 340,000 yr between the Olduvai subchron and the Cobb Mountain event. The lowest layer, about 1.66 million years old (Myr), provides the oldest record of stone-tool processing of animal tissues in east Asia. The highest layer, at about 1.32 Myr, correlates with the stone tool layer at Xiaochangliang, previously considered the oldest archaeological site in this region. The findings at Majuangou indicate that the oldest known human presence in northeast Asia at 40 degrees N is only slightly younger than that in western Asia. This result implies that a long yet rapid migration from Africa, possibly initiated during a phase of warm climate, enabled early human populations to inhabit northern latitudes of east Asia over a prolonged period.

Earliest presence of humans in northeast Asia

The timing of the earliest habitation and oldest stone technologies in different regions of the world remains a contentious topic in the study of human evolution. Here we contribute to this debate with detailed magnetostratigraphic results on two exposed parallel sections of lacustrine sediments at Xiaochangliang in the Nihewan Basin, north China; these results place stringent controls on the age of Palaeolithic stone artifacts that were originally reported over two decades ago. Our palaeomagnetic findings indicate that the artifact layer resides in a reverse polarity magnetozone bounded by the Olduvai and Jaramillo subchrons. Coupled with an estimated rate of sedimentation, these findings constrain the layer's age to roughly 1.36 million years ago. This result represents the age of the oldest known stone assemblage comprising recognizable types of Palaeolithic tool in east Asia, and the earliest definite occupation in this region as far north as 40 degrees N.

Evidence for alternative splicing in hepatic alpha 1B-adrenergic receptor gene expression

The interactions of catecholamines with alpha 1B-adrenergic receptors (alpha 1B-AR) located on the surface of many cell types are responsible for physiologic and pathologic functions in mammalian systems. Transcription of the alpha 1B-AR gene leads to the expression of multiple alpha 1B-AR mRNAs that are distributed in a tissue-specific fashion. The purpose of this study was to define the 5'-untranslated regions of the multiple alpha 1B-AR gene transcripts. Evidence for a previously unidentified intron in the alpha 1B-AR gene upstream of the receptor open reading frame was obtained via rapid amplification of cDNA ends. A product was amplified and was found to be missing the nucleotide interval from -708 to -194, (+1 is the start of translation). Evidence for tissue-specific alternative intron splicing was obtained from ribonuclease protection assays and RT-PCR experiments. Using an RNA probe extending from -240 to +93 and including 45 nucleotides into the putative intron, a single protected fragment was detected in heart RNA while two protected fragments were detected in liver RNA. RT-PCR amplification of the region spanning the intron resulted in detection of two PCR products in liver RNA and no detectable product in heart RNA. These findings emphasize the complexity of alpha 1B-AR gene regulation and suggest that multiple alpha 1B-AR mRNAs with different 5'-UTRs may play a role in regulating alpha 1B-adrenergic responsiveness.

Polymorphism of the gene encoding a human minimal potassium ion channel (minK)

A gene (minK) that encodes a minimal potassium channel has been cloned recently. We describe in this paper a human minK sequence which differs from the original sequence with a single A-->G at position 112. This resulted in a change from a Ser codon (AGT) to a Gly codon (GGT) and created a new MspAI restriction site. Of the 32 alleles from 16 subjects studied, 25 had this newly discovered sequence and 7 had the previously described sequence.

Regulation of alpha 1b-adrenergic receptor gene expression in rat liver cell lines

alpha 1b-Adrenergic receptor gene expression was investigated in two rat hepatic cell lines, Clone 9 and McA-RH7777 cells. By Northern blot analysis, Clone 9 cells expressed a 2.7 kb alpha 1b-adrenergic receptor gene transcript whereas two transcripts, 3.3 kb and 2.7 kb, were observed in total cellular RNA isolated from rat liver. A binding site for the alpha 1-adrenergic antagonist [3H]prazosin was observed in Clone 9 cell membrane preparations (Bmax = 47 +/- 7 fmol/mg protein and Kd = 0.11 +/- 0.02 nM, n = 5). In contrast, alpha 1b-adrenergic receptor gene transcripts could not be detected in total cellular RNA prepared from McA-RH7777 cells by either Northern blot analysis or ribonuclease protection assays. However, results from nuclear run-off assays indicated that the alpha 1b-adrenergic receptor gene was transcribed in McA-RH7777 cells and alpha 1b-adrenergic receptor gene transcripts were observed in McA-RH7777 cell nuclear RNA. These results suggest that alpha 1b-adrenergic receptor gene expression in liver may be regulated in part post-transcriptionally and that this level of regulation may be altered or disrupted in the Clone 9 and McA-RH7777 cell lines.

Two alpha 1b-adrenergic receptor mRNAS expressed in Sprague-Dawley rat liver have distinct 5'-regions

Previous studies have revealed two size classes of alpha 1b-adrenergic receptor mRNAs, 3.3 kb and 2.7 kb, in the Sprague Dawley rat that are transcribed from a single gene and are expressed in approximately equal amounts in liver. Only the 2.7 kb mRNA is expressed in heart. Both alpha 1b-adrenergic receptor mRNAs appear to share extensive regions of homology, therefore, we used oligonucleotide-directed ribonuclease H mapping to detect sequence differences between the two transcripts. Initial experiments using oligo (dT)-directed RNase H hydrolysis indicated that the two mRNAs have poly [A+] tails of identical length. By using region-specific cDNA probes, we determined that the sequence difference between the two alpha 1b-adrenergic receptor mRNAs lies in the 5' end, upstream from the known initiator AUG in the 2.7 kb transcript. In addition, results from ribonuclease protection assays and Northern blot analysis in which an oligonucleotide was used as the probe suggested that both alpha 1b-adrenergic receptor mRNAs are transcribed from the same DNA strand.