Objective To explore the changes and significance of matrix metalloproteinase 3 (MMP3) during wound healing in rat. Methods Wound fluids and dermal pluripotent stem cells (DPSCs) were isolated with routine method from rats, and they were purified and expanded. Wound fluid was collected on the first day to serve as wound microenvironment, then the responses of DPSCs to wound fluids were investigated, and the expression of MMP3 protein in DPSCs was determined by immunohistochemistry staining. Meanwhile, animal models were repruduced with cutaneous incision and suturing, and the animals were respectively assigned to intractable wound group, in which rats received whole body irradiation, and simple wound group, in which no irradiation was given. The rats were sacrificed on 3rd, 5th, 7th, 10th and 14th day posttrauma (n=5 each), and specimens of wound tissue were harvested, fixed with 10% formalin solution. Twenty four hours later, the samples were dehydrated and embeded, then paraffin section were made. Paraffin sections were stained with hematoxylin and eosin (HE) staining. Light microscopy was used to observe the pathological changes in wounds. Five randomly selected fields were observed under a ?40 objective to evaluate the histological features, especially the amount of tissue repairing cells in wounds. Furthermore, MMP3 contents in wound sites were determined by immunohistochemistry assay and image analysis. Results The expression of MMP3 in DPSCs increased significantly after stimulation by wound fluids. MMP3 contents in rats of simple wound group increased significantly, especially in the dermal tissues, and the peak value appeared 5-7 days after trauma. MMP3 contents in rats of intractable wound group were significantly less than those of simple wound group, and the time when the peak value appeared was also delayed till the 10th day after trauma. Conclusions MMP3 may be an important substrate involved in wound healing. DPSCs may participate in the processes of wound repairing via high expression of MMP3.

Objective To explore the influencing factors during long-distance transportation and medical rescue of trauma patients in Wenchuan earthquake. Methods After Wenchuan earthquake, based on prehospital care scheme, we organized medical coordinators and psychologically trained medical staff in emergency medicine, cardiovascular medicine and logistics to transport trauma patients and pro-vide early psychological intervention during whole course of transportation. Results A total of 162 trauma patients were safely transported from Sichuan province to Chongqing relying on prehospital care scheme, equipment supplies, integrated rescue mode and psychological intervention during the transporta-tion. Conclusions Medical rescue mode and psychological intervention indicate that it is necessary to conduct psychological intervention for better transportation of patients for further medical treatments. In the meantime, we should establish medical rescue system for coping with psychological stress, improve rescue preparation scheme and professional medical care team for long-distance transportation and guaran-tee sufficient medical supplies in station hospitals.

AIM: To clone mouse pdx-1 gene and construct its eukaryotic expression vector for expression of pdx-1 in mouse embryonic stem cells.METHODS: Mouse pdx-1 cDNA fragment was amplified with polymerase chain reaction (PCR) from mouse pancreatic cDNA. The purified fragment was recombinated with a eukaryotic expression vector carrying enhanced green fluorescent protein, pEGFP-N1. The pdx-1 cDNA fragment was inserted into the multi-clone sites of the vector to construct a new plasmid, pEGFP/pdx-1. E.colli strain DH5? was transfected with the new recombinant plasmid to expand it. Plasmid DNA extracted from the expanded DH5? was identifed by cutting with Hind Ⅲ, BamHⅠ nuclease and by DNA sequencing. Identified plasmid DNA was transfected into mouse embryonic stem cell line MESPU13 by carrying with liposome. RESULTS: A 876 bp cDNA fragment was amplified from mouse pancreatic cDNA by PCR and it was inserted into the vector pEGFP-N1 correctly. The fragment was defined to be pdx-1 gene by nuclease digestion and DNA sequencing. Mouse embryonic stem cell line MESPU13 was transfected with the new recombinant plasmid DNA. The green fluorescent protein report gene and pdx-1 gene expressed in transfected mouse embryonic stem cells within 24 h. CONCLUSION: Mouse pdx-1 gene is cloned and its recombinant eukaryotic expression vector carrying green fluorescent protein is constructed successfully. It provides a useful tool for further research on the function of pdx-1.

BACKGROUND:It is reported that tailless-like protein (TLX) plays critical roles in the regulation of early developmental processes in vertebrates, and it plays a key role in stem cells proliferation and differentiation into neurons. OBJECTIVE: To construct recombinant plasmid pEGFPN1-TLX and study the transfection into dermal multipotential stem cells. DESIGN, TIME AND SETTING: Cytogene experiment was performed at the Department of Pathogen Biology, School of Basic Medical Science, the Third Military Medical University of Chinese PLA from March to December 2007. MATERIALS: An adult SD was obtained from the Experimental Animal Center of the Third Military Medical University of Chinese PLA; dermal moltipotential stem cells (DMSCs) were cultured by the Institute of Combined Injury of the Third Military Medical University of Chinese PLA; pEGFPN1 and DH5α was gifted by professor Xu.METHODS: Total RNA was extracted from rat brain tissue to amplify TLX-coded cDNA sequence using RT-PCR. T/A was cloned on pMD18-T vector and determined using BamHI and Hindlll. The products were positive recombinant plasmid pMD18-T-TLX segments, which were sub-cloned in pEGFPN1 to construct recombinant plasmid pEGFPN1-TLX. Finally, pEGFPN1-TLX was transfected into DMSCs.MAIN OUTCOME MEASURES: The fluorescence protein expression was observed under fluorescence microscope at 24 hours after transfection; TLX mRNA expression was detected using RT-PCR; neuronal differentiation was observed using immunohistochemical staining.RESULTS: TLX full length cDNA was successfully cloned into pEGFPN1, and pEGFPN1-TLX was successfully constructed by means of sequence analysis and enzyme cutting identification. As compared with non-transfected DMSCs, pEGFPN1-TLX transfected DMSCs were observed after 10 days, formed resistant clones after 15 days, and shown a green fluorescent protein expression. However, non-transfected DMSCs died at day 10. RT-PCR indicated that pEGFPN1-TLX transfected DMSCs could express TLX mRNA. At day 3 after induction, NF200 positive cells were increased, but glial fibrillary acidic protein positive cells were decreased after induction of pEGFPN1-TLX transfected DMSCs.CONCLUSION: TLX was successfully constructed and transfected into DMSCs. After transfection, neuronal differentiation of DMSCs was enhanced, and the differentiation to gliocytes was inhibited.

China's cardiopulmonary resuscitation (CPR) training in the form of a Chinese tutor classes for the training of CPR has spread across the country. It is supported by three Chinese original theoretical systems: "2016 Chinese cardiopulmonary resuscitation expert consensus", "2018 China cardiopulmonary resuscitation training expert consensus", and "Chinese public health guidelines for cardiopulmonary resuscitation". There are five characteristics in the classes, such as the "three analysis" "three-prevention" (precaution, prewarning and early identification),"three-ways" (standardization, diversification and individuation), "three lives" (demutation, transcending and extension),"three dimensional" (time, space and society). Highlighting the Chinese CPR training of the "three training" policy for CPR training (the cultivation of a sound system, the cultivation of scientific guidelines and the cultivation of a healthy culture), the "three training" program of CPR training (training professional skills, training multidimensional and training flexible ), the "three party" direction of CPR training (the application for achievement translation, the precision disseminators and theoretical innovation guides) under the new era background. A new chapter of CPR training with Chinese characteristics was composed.

Investigation on the pathways of embryonic stem cells differentiation into insulin-producing cells is of importance to pancreatic tissue-engineering. Instead of passing through the classic multi-step-inducing method, the expanded embryonic stem cells that were cultured and expanded in the presence of mouse embryonic fibroblast feed-layer and leukemia inhibitory factor (LIF) were induced into insulin-producing cells directly. The results showed a similar consequence from two different inducing cultures. Without passing through a so-called indispensable differentiation phase, the neural-precursor-cell-stage, the expanded embryonic stem cells could be induced into insulin-producing cells. The insulin-producing cells population resulting from our modified method were similar to that resulting from the classic multi-step method (passing through the neural-precursor-cells-stage), thus suggesting that neural-precursor-cell-phase is not the indispensable checkpoint of embryonic stem cell differentiation into insulin-producing cells. Embryonic stem cells can be induced into insulin-producing cell by classic multi-step inducing method or by direct inducing method.
Animals ; Cell Differentiation ; Cells, Cultured ; Embryonic Stem Cells ; cytology ; Insulin-Secreting Cells ; cytology ; Mice ; Neural Stem Cells ; cytology

Animals ; Leukocyte Count ; Leukocytes ; drug effects ; Male ; Mice ; Nerve Growth Factor ; pharmacology ; Skin ; pathology ; radiation effects ; Survival Rate ; Whole-Body Irradiation ; adverse effects ; mortality ; Wound Healing ; drug effects

Objective:To explore and establish the scoring method of injury assessment in rats with trauma combined with seawater immersion, so as to provide a reference for injury assessment in the special environment of trauma combined with seawater immersion.Methods:Sixty-four SD rats were divided into two groups according to the random number table, including hemorrhagic shock group and compound injury group, with 32 rats per group. Each group was divided into trauma combined with seawater immersion group and simple trauma group, with 16 rats per group. In trauma combined with seawater immersion group, the hemorrhagic shock model was placed in 15℃ seawater for 1 hour to start bleeding, and the blood loss was 30% of the total blood volume. The composite injury model caused 10% Ⅱ degree burns and was incised along the vental midline with a length of about 2 cm, and then placed in 15℃ seawater for 1 hour. The death and survival time were recorded.The survival time significantly longer than 4 hours out of water was recorded as survival, and significantly shorter than 4 hours out of water was recorded as death. Data were observed within 9 hours after injury, including the changes of physiological indexes (respiration, blood pressure, anal temperature) and arterial blood gas (blood glucose, pH value, blood lactic acid, arterial oxygen partial pressure, arterial carbon dioxide partial pressure, bicarbate, sodium ion, chloride ion, calcium ion, potassium ion). Each index were compared between trauma combined with seawater immersion group and simple trauma group. According to the survival situation of all the trauma combined with seawater immersion group at 4 hours out of water, the rats were divided into survival group and death group. The indicators affecting survival were screened, and then the scatter plot of each index corresponding to the mortality rate was established. According to the trend of each index in different interval in the scatter chart, the score table of injury condition was established.Results:The total mortality was 28% (9/32) in trauma combined with seawater immersion group, and was 6% (2/32) in simple trauma group ( P<0.05). The survival time in trauma combined with seawater immersion group [(8.1±3.7)hours] was shorter than that in simple trauma group [(11.3±4.8)hours] ( P<0.05). In trauma combined with seawater immersion group, the respiratory rate[(58.8±2.9)times/min] was slower than that in simple trauma group [(100.4±7.2)times/min], blood pressure [(80.0±25.1)mmHg] was lower than that in simple trauma group [(89.8±18.1)mmHg], and anal temperature [22.4(20.1, 25.0)℃] was significantly lower than that in sample trauma group [31.7(30.5, 33.2)℃], pH value (7.1±0.1) was lower than that in simple trauma group (7.3±0.1), and arterial oxygen partial pressure [(196.3±34.1)mmHg], arterial carbon dioxide partial pressure [45.5(35.1, 51.1)mmHg], serum sodium [145(142, 148)mmol/L], serum chlorine [120(115, 125)mmol/L], serum calcium [(1.3±0.1)mmol/L]as well as serum potassium [(3.6±0.8)mmol/L] were higher than those in simple trauma group [(149.4±22.6)mmHg, 29.7(25.6, 34.5)mmHg, 142(139, 144)mmol/L, 118(114, 121)mmol/L, (1.2±0.1)mmol/L, (3.3±0.6)mmol/L] (all P<0.05). There were no significances in other indexes between the two groups ( P>0.05). In death group, the breathing[36(30, 36)times/min], blood pressure [(43.1±21.8)mmHg], anal temperature [(20.0±1.9)℃], pH value (7.1±0.1), and bicarbonate [(12.3±2.2)mmol/L] were significantly inhibited or suppressed compared with survival group [60(48, 78)times/min, (86.6±19.3)mmHg, (23.0±3.1)℃, 7.2±0.1, (14.6±2.3)mmol/L (all P<0.05). While the two groups showed no significant differences in other indices ( P>0.05). Therefore, the respiration, blood pressure, rectal temperature, pH value and bicarbonate that significantly affect the survival of rats were screened. According to the death rate corresponding to different intervals, a score value was assigned to the interval as the weight of its impact on survival, namely on the severity of the injury, and an injury score table for trauma combined with seawater immersion in rats was established. The injury scoring scale <6 points indicated no death, 6-9 points indicated the mortality of 50%, ≥9 points indicated the mortality of 71%. The 6 points and 9 points were cutoff value of the scale. It can be considered that the scale of <6 points was classified as minor injury, 6-9 points as moderate injury, and ≥9 points as severe injury. Conclusions:The seawater immersion can result in reduced survival time and increased early mortality, manifested as respiratory depression, more serious blood loss, severe hypothermia, severe metabolic acidosis, water and electrolyte disorders (high sodium, high chlorine, high calcium, and high potassium), etc. According to the respiration, blood pressure, anal temperature, pH value and bicarbate, which affect the survival of rats, the injury rating scale of rats with trauma combined with seawater immersion can be established by using the scatter chart. The predicted mortality rate by using the rating scale was roughly consistent with the actual mortality rate, so the injury rating scale basically had a good prediction and hint for the trauma rats combined with seawater immersion.

OBJECTIVETo study the effects of dosages of total body irradiation on the healing process of cutaneous wounds and to observe the changes of wound area at different periods after injury.

METHODSThe entire body irradiation from a (60)Co gamma-ray source was performed on Wistar rats. The single dosage varied from 1 to 8 Gy. Within 1 h after irradiation, two whole thickness circular cutaneous wounds corresponding to 2.5% of total body surface area (Phi = 22 mm) were produced on the back of the animals (combined injury groups). Same wounds were produced on rats with no irradiation (single wound group). Wound healing was observed at different points after injury.

RESULTSAfter total body irradiation with the dose of 1, 2, 3, 4, 5, 6, 7 or 8 Gy, the wound healing was obviously retarded as the dosages increased. The wound area remained was larger in the large dosage groups than in the small dosage groups. Seven days after injury, there was 33.5% wound surface left unhealed in the single wound group, whereas in the combined injury groups, 35.4%, 38.1%, 41.6%, 48.8%, 53.9%, 63.7%, 69.2% and 73.9% of the wound surfaces remained unhealed, respectively. Statistical analysis showed marked correlations between the various times after total body irradiation and various dosages to the percentage of unhealed wound surface. Nine dose-effect relation formulae were deduced according to the statistical results.

CONCLUSIONSIn soft tissue trauma combined with radiation injury, the delay of wound healing is related to the dose of radiation inflicted. It is also related to the time between injury and time of observation.

Animals ; Dose-Response Relationship, Radiation ; Female ; Male ; Rats ; Rats, Wistar ; Time Factors ; Whole-Body Irradiation ; Wound Healing ; radiation effects

During coronavirus disease 2019 epidemic, the treatment of severe trauma has been impacted. The Consensus on emergency surgery and infection prevention and control for severe trauma patients with 2019 novel corona virus pneumonia was published online on February 12, 2020, providing a strong guidance for the emergency treatment of severe trauma and the self-protection of medical staffs in the early stage of the epidemic. With the Joint Prevention and Control Mechanism of the State Council renaming "novel coronavirus pneumonia" to "novel coronavirus infection" and the infection being managed with measures against class B infectious diseases since January 8, 2023, the consensus published in 2020 is no longer applicable to the emergency treatment of severe trauma in the new stage of epidemic prevention and control. In this context, led by the Chinese Traumatology Association, Chinese Trauma Surgeon Association, Trauma Medicine Branch of Chinese International Exchange and Promotive Association for Medical and Health Care, and Editorial Board of Chinese Journal of Traumatology, the Chinese expert consensus on emergency surgery for severe trauma and infection prevention during coronavirus disease 2019 epidemic ( version 2023) is formulated to ensure the effectiveness and safety in the treatment of severe trauma in the new stage. Based on the policy of the Joint Prevention and Control Mechanism of the State Council and by using evidence-based medical evidence as well as Delphi expert consultation and voting, 16 recommendations are put forward from the four aspects of the related definitions, infection prevention, preoperative assessment and preparation, emergency operation and postoperative management, hoping to provide a reference for severe trauma care in the new stage of the epidemic prevention and control.