Distribution and drug resistance of wound pathogenic microorganisms in outpatients of wound healing center / 中华创伤杂志

Objective:To analyze the distribution and drug resistance of wound pathogenic microorganisms in outpatients of wound healing center so as to provide a basis for the standardized construction of wound healing centers.Methods:A retrospective case series study was used to analyzed the data of 365 outpatients treated at Ruijin Hospital, Shanghai Jiaotong University School of Medicine from December 2017 to October 2019. There were 220 males and 145 females, aged (58.8±18.9)years (range, 18-98 years). The patients included 92 first-visit patients and 273 re-visit patients. The culture results (positive rate of pathogenic microorganisms, bacterial species, bacterial distribution) and drug sensitivity results of the wound secretions were compared and analyzed.Results:(1) Among 365 samples of wound secretions, 198 patients were positive for pathogenic microorganisms with a positive rate of 54.3%. A total of 107 strains (51.0%) of Gram-positive bacteria were detected, mainly Staphylococcus aureus (70 strains, 33.3%); 95 strains (45.2%) of Gram-negative bacteria were detected, mainly Escherichia coli (20 strains, 9.5%), followed by Pseudomonas aeruginosa (17 strains, 8.1%); 8 strains (3.8%) of fungi were detected. (2) A total of 26 (28.3%) first-visit patients were positive for pathogenic microorganisms, and 172 (63.0%) re-visit patients were positive for pathogenic microorganisms. The rate of positive microorganism detection had significant differences between first-visit and re-visit patients ( P<0.05). (3) A total of 29 strains were detected in first-visit patients, including 16 strains (55.2%) of Gram-positive bacteria, 11 strains (37.9%) of Gram-negative bacteria and 2 strains (6.9%) of fungi. A total of 181 strains were detected in re-visit patients, including 91 strains (50.3%) of Gram-positive bacteria, 84 strains (46.4%) of Gram-negative bacteria and 6 strains (3.3%) of fungi. The microbial distribution was significantly different between first-visit and re-visit patients ( P<0.05). (4) Compared with first-visit patients, the resistance of Staphylococcus aureus isolated from the re-visit patients to spenicillin, oxacillin, ciprofloxacin, tetracycline, clindamycin, moxifloxacin, erythromycin, and levofloxacin were increased variably. No vancomycin-resistant Staphylococcus aureus was detected, indicating that the staphylococcus aureus presented in the wound was highly sensitive to vancomycin. Conclusions:Staphylococcus aureus is the most common microorganism in wound secretions in outpatients of wound healing center. The rate of positive pathogenic microorganisms in wound secretions of re-visit patients is significantly higher than that of first-visit patients, and the distribution of pathogenic microorganisms of first-visited and revisited patients differs significantly. The Staphylococcus aureus detected in re-visit patients has a higher resistance to common antibiotics compared with first-visit patients. It is suggested that timely detection of pathogenic microorganisms in outpatients and effective control and supervision of outpatient infections are important contents that cannot be ignored in the construction of wound healing center.

Attention should be paid to the exposure risk of patients with chronic wounds on the way to hospital during corona virus disease 2019 epidemic prevention and control / 中华烧伤杂志

Statistics show that 76.74% (4 688) of 6 109 patients with chronic wounds are those over 50 years of age; the proportion of patients with underlying diseases in all age groups above 50 years ranges from 78.25% to 100.00%; among the underlying diseases of chronic wound patients, the top four diseases are diabetes mellitus , cardiovascular and cerebrovascular diseases, hypertension, and respiratory diseases. The above underlying diseases and ages of patients are the susceptibility factors of corona virus disease 2019 released by National Health Commission of China. It is an unavoidable fact that patients with chronic wounds have to go to the hospital for treatment prescribed by the physician. At the same time, we found that there were not a few patients who go far afield because of various reasons when go to the hospital for treatment. During the period of epidemic prevention and control, this kind of "go far afield" style of seeking medical treatment may increase the exposure risk during transportation. Accordingly, we convened 36 wound care clinics in different regions in Shanghai to implement the "Five Measures" to encourage patients with chronic wounds to seek medical treatment proximately. The principle of this operation is that when seeking medical treatment, trying our best to reduce as much as possible the transportation distance for patients with chronic wounds to minimize the exposure risk during the epidemic period and eventually support the epidemic prevention and control campaign.

Study on the clinical benefits of endoscopy combined with contrast fistulography in the diagnosis and treatment of chronic wound with sinus tract adjacent to body cavity / 中华烧伤杂志

Objective@#To explore the advantages of endoscopy combined with contrast fistulography in the clinical diagnosis and treatment of chronic wound with sinus tract adjacent to body cavity.@*Methods@#Thirty-two patients (14 males and 18 females, aged 17 to 87 years) of chronic wounds with sinus tracts adjacent to body cavity, who underwent endoscopy combined with contrast fistulography (CT or magnetic resonance imaging) for the diagnosis and treatment in the Outpatient Department of Wound Healing Center of our hospital from October 2017 to March 2019, were enrolled in the study. Their diagnosis and treatment results were retrospectively analyzed. The following data were calculated. (1) The incidence rates of sinus wound involving body cavity or fistula. (2) The detection rates of sinus wound involving body cavity detected by routine examination and by endoscopy combined with contrast fistulography. (3) The detection rate of pathological features at deep part of wound by routine examination and by endoscopy combined with contrast fistulography. (4) The proportion of patients who benefited from routine examination and from endoscopy combined with contrast fistulography. Data were processed with paired chi-square test and Fisher′s exact probability test.@*Results@#(1) The incidence rate of sinus wound involving body cavity was 43.75% (14/32); the incidence rate of fistula was 0. (2) The detection rate of sinus wound involving body cavity detected by endoscopy combined with contrast fistulography was 43.75% (14/32), which was obviously higher than that by routine examination [12.50% (4/32), χ2=32.0, P<0.01]. (3) The detection rate of pathological features at deep part of wound by endoscopy combined with contrast fistulography was 37.50% (12/32), which was obviously higher than that by routine examination (0, P<0.01). (4) The proportion of patients who benefited from endoscopy combined with contrast fistulography was 71.43% (20/28), which was obviously higher than that from routine examination [12.50% (4/32), χ2=21.6, P<0.01].@*Conclusions@#Compared with routine examination, endoscopy combined with contrast fistulography is more accurate in detecting chronic wound with sinus tract adjacent to body cavity. The diagnosis and treatment of chronic wound with sinus tract adjacent to the body cavity can benefit from this joint examination.

Diagnosis and treatment standard for treatment with endoscopy technique in chronic wounds with sinus tract (trial version) / 中华烧伤杂志

The " exploration of treatment technology of chronic wound with sinus tract supported by endoscope and related auxiliary methods" study had been conducted by Wound Healing Center of Ruijin Hospital, Shanghai Jiao Tong University School of Medicine. The feasibility and effectiveness of this technique have been confirmed, and good clinic results have been achieved. In order to further promote the new technology and its related research, the theoretical knowledge and technical experience accumulated in the early stage are summarized as diagnosis and treatment standard for treatment with endoscopy technique in chronic wounds with sinus tract, including four parts: the applicable subjects, the diagnosis and treatment procedures and classification criteria, the healing criteria, and the risk assessment and prevention measures. The purpose of this standard is to facilitate the application of standardized endoscopy technique, to make the most of its technological advantages, prevent risks, and provide a reference for the official version of the diagnosis and treatment standard.

Preliminary evaluation and mechanism of adipose-derived stem cell transplantation from allogenic diabetic rats in the treatment of diabetic rat wounds / 中华烧伤杂志

Objective@#To investigate whether adipose-derived stem cells (ASCs) from allogeneic diabetic rats can promote wound healing in diabetic rats or not and the mechanism.@*Methods@#(1) Fifty-six male Wistar rats aged 12-16 weeks were divided into diabetic group and healthy group according to the random number table (the same grouping method below), with 28 rats in each group. Rats in healthy group were not treated with any treatment. Rats in diabetic group were injected with 10 g/L streptozotocin 60 mg/kg intraperitoneally in one time to establish the diabetic model. Four rats in diabetic group and 4 rats in healthy group were selected according to the random number table, and the adipose tissue in the inguinal region was taken to culture and purify ASCs, so as to obtain healthy rat-derived ASCs (hereinafter referred to as nASCs) and diabetic rat-derived ASCs (hereinafter referred to as dASCs). The third passage of nASCs (n=3) and dASCs (n=3) were taken, and the positive expression rates of cell surface differentiation antigens CD105, CD31, CD34, and CD44 were detected with flow cytometer for defining ASCs purity. (2) The rest 24 rats in healthy group and 24 rats in diabetic group were used to make three round full-thickness skin defect wounds with a diameter of 12 mm on the back of each rat. Immediately after injury, phosphate buffer saline (PBS), nASCs of 2×107/mL, and dASCs of 2×107/mL each in the volume of 0.5 mL were subcutaneously injected into three wounds and their margins of each rat, respectively. On post injury day (PID) 1, 3, 7, and 12, 6 rats in each group were selected according to the random number table to calculate the wound area, and the wound tissue was stained with hematoxylin-eosin to observe the histological morphology of the wound. (3) Human ASCs (hASCs) were subcultured, and the 4th to 7th passage of cells were used for the subsequent experiments. The hASCs were divided into 7 groups, with 12 samples in each group. Cells in blank control group were cultured with mesenchymal stem cell culture medium, and cells in simple advanced glycation end products (AGEs) group, simple protein group, simple high glucose group, simple high osmotic pressure group, AGEs-high glucose combination group, and protein-high osmotic pressure combination group were cultured with mesenchymal stem cell culture medium containing a final mass concentration of 100 mg/L AGEs, 100 mg/L bovine serum albumin (BSA), 28 mmol/L D-glucose, 28 mmol/L mannitol, 100 mg/L AGEs+ 28 mmol/L D-glucose, 100 mg/L BSA+ 28 mmol/L mannitol, respectively. Cell proliferation was detected by cell counting kit 8 at post culture hour (PCH) 2 and on post culture day (PCD) 2, 4 and 6. (4) The hASCs were divided into blank control group, simple AGE group, simple high glucose group, and AGE-high glucose combination group, with 12 samples in each group, which were treated the same as corresponding groups in experiment (3). On PCD 0, 2, 4, and 6, the positive expression rates of cell surface differentiation antigens CD105, CD44, and CD45 were detected by flow cytometer to estimate their homeostasis. (5) The hASCs were divided into AGE-high glucose combination group and protein-high osmotic pressure combination group, with 9 samples in each group, which were treated the same as corresponding groups in experiment (3). On PCD 2, 4, and 6, the expression of intracellular protein was detected by cyanine 3-streptavidin double-antibody sandwich technique. Data were processed with analysis of variance for factorial design, least significant difference test, and Bonferroni correction.@*Results@#(1) The positive expression rates of CD44 in nASCs and dASCs were both higher than 96%, the positive expression rates of CD31 and CD34 were low, and the positive expression rates of CD105 were about 40%, which basically met the purity requirements. (2) The areas of wounds treated by three methods in rats of healthy group and diabetic group were similar on PID 1 (P>0.05). In healthy group, compared with (0.682 1±0.078 9), (0.314 3±0.113 7), and (0.064 3±0.002 1) cm2 of the PBS-treated wounds in rats, the area of nASCs-treated wounds in rats decreased significantly on PID 3, 7, and 12 [(0.464 1±0.092 6), (0.223 9±0.072 7), and (0.034 3±0.012 5) cm2, P<0.05], the area of dASCs-treated wounds in rats decreased significantly on PID 3 and 12 [(0.514 1±0.124 1) and (0.043 7±0.032 8) cm2, P<0.05] but was not obviously changed on PID 7 [(0.274 2±0.062 5) cm2, P>0.05]. Compared with those of the dASCs-treated wounds of rats within the same group, the area of the nASCs-treated wounds of rats in healthy group decreased significantly on PID 3 and 7 (P<0.05) but was not obviously changed on PID 12 (P>0.05). In diabetic group, compared with (0.853 5±0.204 8), (0.670 5±0.164 8), and (0.131 4±0.074 4) cm2 of the PBS-treated wounds in rats, the area of nASCs-treated wounds in rats decreased significantly on PID 3, 7, and 12 [(0.633 4±0.132 5), (0.331 8±0.023 5), and (0.074 2±0.003 8) cm2, P<0.05], the area of dASCs-treated wounds in rats decreased significantly on PID 3 [(0.773 6±0.182 2) cm2, P<0.05] but was not obviously changed on PID 7 and 12 [(0.510 6±0.192 2) and (0.114 4±0.003 1) cm2, P>0.05]. Compared with the dASCs-treated wounds of rats within the same group, the area of the nASCs-treated wounds of rats in diabetic group was not obviously changed on PID 3 and 7 (P>0.05) but decreased significantly on PID 12 (P<0.05). There was no obvious difference in histological morphology of the wounds treated with three methods in rats of each group on PID 1. On PID 3, a small amount of microvessels were formed in the wounds treated with nASCs and dASCs of rats in both groups, but microvessel formation was almost undetected in the PBS-treated wounds. On PID 7, more small blood vessels and fibroblasts (Fbs) were observed in the wounds treated with nASCs and dASCs of rats in both groups, but the small blood vessels and Fbs were slightly less in the PBS-treated wounds. On PID 12, the wounds treated with nASCs and dASCs of rats in the two groups were covered by epithelial tissue, the granulation tissue in the PBS-treated wounds of rats in healthy group was not obvious, and the PBS-treated wounds of rats in diabetic group were not completely epithelialized. (3) Compared with those of blank control group, the cell number of hASCs in simple AGEs group decreased significantly on PCD 2, 4, and 6 (P<0.05), which increased significantly on PCD 2 and 4 in simple high glucose group (P<0.05), and that in AGEs-high glucose combination group decreased significantly on PCD 4 and 6 (P<0.05). (4) Compared with that on PCD 4 within the same group, the positive expression rate of CD105 in hASCs decreased significantly in blank control group, simple AGEs group, and AGEs-high glucose combination group on PCD 6 (P<0.05). The positive expression rate of CD44 was higher than 95%, and that of CD45 was less than 2% in hASCs of each group at each time point. (5) Detection values of 7 proteins were located in the confidence interval. The expression levels of basic fibroblast growth factor and tissue inhibitor of metalloproteinase-1 in hASCs of AGEs-high glucose combination group and protein-high osmotic pressure combination group showed increasing trend with the prolongation of culture time. The expression level of human monocyte chemoattractant protein 1 (MCP-1) in hASCs of AGEs-high glucose combination group showed increasing trend with the prolongation of culture time, while the expression level of growth-regulated oncogene (GRO) on PCD 6 was significantly higher than that on PCD 4 within the same group (P<0.05); the expression levels of MCP-1 and GRO in hASCs of protein-high osmotic pressure combination group showed decreasing trend with the prolongation of culture time. The expression level of follistatin in hASCs of protein-high osmotic pressure combination group decreased obviously on PCD 4, while that in hASCs of AGEs-high glucose combination group was significantly lower on PCD 6 than that on PCD 4 (P<0.05). The expression level of vascular endothelial growth factor (VEGF) in hASCs of protein-high osmotic pressure combination group decreased gradually with the prolongation of culture time, while that in hASCs of AGEs-high glucose combination group on PCD 4 decreased significantly as compared with that on PCD 2 (P<0.05). The expression level of urokinase-type plasminogen activator receptor in hASCs of protein-high osmotic pressure combination group on PCD 6 was significantly higher than that on PCD 4 within the same group (P<0.05) and that of AGEs-high glucose combination group on PCD 6 (P<0.05).@*Conclusions@#Both nASCs and dASCs can promote wound healing in rats with simple defect injury, but dASCs have no significant effect on wound healing in rats with diabetes mellitus, which may be related to the inhibition of ASCs proliferation and the influence of high glucose and AGEs intervention on their homeostasis and secretory function.

Application value of endoscope in probing chronic wound with sinus tract in clinic / 中华烧伤杂志

Objective@#To explore the application value of endoscope in probing the chronic wound with sinus tract in clinic.@*Methods@#Twenty-eight chronic wounds with sinus tracts from 27 patients conforming to the inclusion criteria admitted to Outpatient Department of Wound Healing Center of Ruijin Hospital from December 2017 to March 2018 were investigated in a prospective and self-controlled trial. After being cleaned, the diameter of the opening of sinus tract was measured with a rule. A probe was used to measure the depth of a sinus tract according to the touch from the probe extremity in operation, and to measure the depth of a sinus tract that could be observed with naked eyes with the help of a pair of hemostatic forceps. Five minutes later, a probe was inserted deeply into the sinus tract to measure the depth under the endoscopic view combined with touch from the probe extremity in operation. Afterwards, the sinus tract was observed with endoscope, and the depth of the tract which could be observed under the endoscopic view was measured using a probe inserted deeply into the sinus tract. After completion of the above exploration, the sinus tract was infused with contrast agent Omnipaque 350 and scanned by computed tomography (CT) later to obtain its depth. The following indicators were calculated: the ratio of the depth of the sinus tract measured by CT to the diameter of the opening of the sinus tract (hereinafter referred to as the depth/diameter ratio of the sinus tract), the deviation rate comparing the depth of the sinus tract measured by conventional method (measured by probe only) and by endoscope (measured by probe under the endoscope view) with the depth of the sinus tract measured by CT (hereinafter referred to as the deviation rate of the measured depth of the sinus tract), the deviation rate comparing the depth of the sinus tract that could be observed measured by conventional method and by endoscope with the depth of the sinus tract measured by CT (hereinafter referred to as the deviation rate of the depth of the sinus tract that could be observed). Data were processed with paired t test. Pearson correlation analysis was applied to analyze the correlation between the depth/diameter ratio of the sinus tract and the deviation rate of the measured depth of the sinus tract and the deviation rate of the depth of the sinus tract that could be observed by conventional method and by endoscope.@*Results@#The depth/diameter ratio of the sinus tract of this group of wounds was 1-32 (8±7). The deviation rate of the measured depth of the sinus tract and the deviation rate of the depth of the sinus tract that could be observed by conventional method were (19±14)% and (79±18)%, respectively, both obviously larger than (9±9)% and (25±25)% by endoscope (t=3.837, 13.626, P<0.01). Positive correlation existed between the depth/diameter ratio of the sinus tract and the deviation rate of the measured depth of the sinus tract by conventional method, and between the depth/diameter ratio of the sinus tract and the deviation rate of the depth of the sinus tract that could be observed by conventional method and by endoscope (r=0.514, 0.585, 0.651, P<0.01). However, there was no obvious correlation between the depth/diameter ratio of the sinus tract and the deviation rate of the measured depth of the sinus tract by endoscope (r=0.113, P>0.05).@*Conclusions@#Compared with the conventional method, application of endoscope is able to get more accurate data of chronic wounds with sinus tracts and observe the wounds with wider range.

Effects of denatured collagen type Ⅰ on differentiation of human fibroblasts into myofibroblasts / 中华烧伤杂志

Objective@#To investigate the effects of denatured collagen type Ⅰ on differentiation of human fibroblasts into myofibroblasts.@*Methods@#A small amount of normal skin donated by burn patients undergoing scar surgery was collected. Human fibroblasts were obtained by method of explant culture and then sub-cultured. The fourth passage of cells were used in the following experiments. (1) Fibroblasts were divided into normal collagen group and denatured collagen group according to the random number table, with 10 wells in each group. Fibroblasts in normal collagen group were cultured on normal collagen type Ⅰ coated coverslips. Fibroblasts in denatured collagen group were cultured on denatured type Ⅰ collagen coated coverslips. Expression of proliferating cell nuclear antigen (PCNA) was detected by immunohistochemical method, and the percentage of PCNA positive cells was calculated. (2) Another batch of fibroblasts were grouped and treated as in (1), with 12 wells in each group. Proliferation activity of cells was determined with methyl-thiazolyl-tetrazolium colorimetry method. (3) Another batch of fibroblasts were grouped and treated as in (1), and the microfilament morphology of cells was observed by rhodamine-phalloidin staining. (4) Another batch of fibroblasts were grouped and treated as in (1). Expression of α smooth muscle actin (α-SMA) of cells was detected by immunohistochemical method, and expression of OB-cadherin of cells was detected by immunofluorescence method. (5) Another batch of fibroblasts were divided into normal collagen, denatured collagen, and common coverslips groups according to the random number table, with 6 wells in each group. Fibroblasts in normal collagen and denatured collagen groups were treated as in (1), while fibroblasts in common coverslips group were cultured on coverslips without collagen coating. Expressions of α-SMA and OB-cadherin of cells were determined with Western blotting. (6) Another batch of fibroblasts were grouped and treated as in (5), and then the mRNA expressions of collagen type Ⅰ, collagen type Ⅲ, and α-SMA of cells were determined with real-time fluorescent quantitative reverse transcription polymerase chain reaction. Data were processed with t test, one way analysis of variance, and least-significant difference test.@*Results@#(1) The percentage of PCNA positive cells in denatured collagen group was (83±9)%, significantly higher than (29±9)% in normal collagen group (t=13.53, P<0.01). (2) The proliferation activity of fibroblasts in denatured collagen group was 0.32±0.06, significantly higher than 0.25±0.05 in normal collagen group (t=3.06, P<0.01). (3) The microfilament of fibroblasts in normal collagen group was arranged vertically and in parallel way, paralleling the long axis of cells. The microfilament of fibroblasts in denatured collagen group was denser and thicker. (4) Most fibroblasts in normal collagen group showed long shuttle-like shape typically. Morphology of fibroblasts in denatured collagen group changed, and cells were obviously spreading. Expressions of α-SMA and OB-cadherin of fibroblasts in denatured collagen group were stronger than those in normal collagen group. (5) Expressions of α-SMA of fibroblasts in denatured collagen, normal collagen, and common coverslips groups were respectively 1.69±0.41, 0.89±0.27, and 1.46±0.42. Expression of α-SMA of fibroblasts in denatured collagen group was significantly higher than that in normal collagen group (P<0.01). Expressions of OB-cadherin of fibroblasts in denatured collagen, normal collagen, and common coverslips groups were respectively 5.17±0.28, 2.21±0.10, and 4.01±0.56. Expression of OB-cadherin of fibroblasts in denatured group was significantly higher than that in normal collagen group (P<0.01). (6) There was no significant difference in mRNA expression of collagen type Ⅰ of fibroblasts in denatured collagen, normal collagen, and common coverslips groups (F=2.71, P>0.05). The mRNA expressions of collagen type Ⅲ and α-SMA of fibroblasts in normal collagen group were significantly lower than those in denatured collagen group (P<0.01).@*Conclusions@#Denatured collagen type Ⅰ may influence the activity of fibroblasts, thus inducing fibroblasts differentiating into myofibroblasts.

Thoughts and principles of diagnosis and treatment of chronic refractory wounds in China / 中华烧伤杂志

The correct thoughts and principles of diagnosis and treatment of chronic refractory wounds need to be formulated. Through the relevant domestic and international consensus and based on clinical experience, the Thoughts and principles of diagnosis and treatment of chronic refractory wounds in China is proposed. It is considered that in the diagnosis and treatment of chronic refractory wounds, in the case of fully understanding the patient′s medical history, the following thoughts and principles should be complied in order. (1) Pay attention to the cleanliness of the wound after being cleaned. (2) Reasonably perform debridement to avoid being " excessive" or " not thorough". (3) Reasonably perform examination, diagnosis, and differential diagnosis of pathogenic factors. (4) Treat according to etiology. (5) Find comorbidities and prevent adverse outcomes. (6) Select the correct wound treatment method reasonably and timely. When the conservative wound care treatment is considered, pay attention to embodying the concept of etiological treatment, treat the wound according to the principles of safety, phase, selectivity, and effectiveness, and make a reasonable choice of continuing conservative treatment or surgical treatment in time after completing the preparation of the wound bed. When surgical treatment is considered, pay attention to the selection of reasonable surgical method and donor site, pay attention to the healing rate of surgical wound site and the outcome of donor site, and give reasonable protection to the wound site after surgery. (7) Carry out rehabilitation treatment after wound healing and related health education.

Hydrogen peroxide: a potential wound therapeutic target?

Hydrogen peroxide [H[2]O[2]] is a topical antiseptic used in wound cleaning which kills pathogens through oxidation burst and local oxygen production. [H[2]O[2]] has been reported to be a reactive biochemical molecule synthesized by various cells that influences biological behavior through multiple mechanisms: alterations of membrane potential, generation of new molecules, and changing intracellular redox balance, which results in activation or inactivation of different signaling transduction pathways. Contrary to the traditional viewpoint that [H[2]O[2]] probably impairs tissue through its high oxidative property, a proper level of [H[2]O[2]] is considered an important requirement for normal wound healing. Although the present clinical use of [H[2]O[2]] is still limited to the elimination of microbial contamination and sometimes hemostasis, better understanding towards the sterilization ability and cell behavior regulatory function of [H[2]O[2]] within wounds will enhance the potential to exogenously augment and manipulate healing

Fibrosis after damage to fat dome structure of skin of pig / 中华烧伤杂志

<p><b>OBJECTIVE</b>To observe the fibrosis of skin after damage to the fat dome structure in skin of pig.</p><p><b>METHODS</b>Totally 4 pieces of skin grafts of intermediate thickness in the size of 5 cm × 5 cm were obtained from both sides beside the spine of back in each of the 4 female red Duroc pigs with pedicle on one side with Humby knife performed by burn specialists, who were rich in clinical experience. These skin grafts were assigned as thin dermis group (TD). Pedicled tissue grafts in the size of 5 cm × 5 cm with the thickness of 1.5 mm were obtained within the wounds resulted from former incision with the same method mentioned above, and these tissue grafts were set as fat dome group (FD). The above-mentioned two groups of skin grafts were sutured back in situ immediately after completion of the former procedures. On post surgery day (PSD) 7, 14, and 21, 5 wounds were respectively selected according to the random number table for gross observation of the surgical areas. Tissue samples were obtained from corresponding surgical area deep to the deep fascia after gross observation at above-mentioned time points. Some of the tissue samples were used for observation of distribution of collagen fibers in the regions of operation of both groups of skin grafts with HE staining, and the breadth of fibrosis was measured; some of the tissue samples were used for observation of distribution of type I or III collagen fibers in the regions of incision of both two groups of skin grafts with Sirius red staining. Data were processed with two independent sample t test.</p><p><b>RESULTS</b>A little scab on the edge of wounds was observed on PSD 7; all the wounds were healed on PSD 14; a few hairs were observed growing in the surgical area on PSD 21. HE staining showed that traces of incision were observed in the superficial layer of dermis and at the junction between dermis and fat dome at each time point; profuse hyperplasia of collagen fibers with parallel and orderly arrangement were observed in the region of incision of skin grafts in groups TD and FD at each time point. The breadth of fibrosis of the region of incision of skin grafts was respectively (251 ± 31), (240 ± 3 7), and (342 ± 69) µm in group TD, (239 ± 36), (286 ± 61), and (332 ± 28) µm in group FD on PSD 7, 14, 21, without significantly statistical difference (with t values respectively 0.750, -1.971, and 0.375, P values above 0.05). Sirius red staining showed that large amount of type III collagen fibers and small amount of type I collagen fibers arranging parallelly were present in the region of incision of skin grafts in groups TD and FD at each time point.</p><p><b>CONCLUSIONS</b>Under the circumstances of relatively intact restoration of dermal tissue, no excessive fibrosis was observed after simple incisional injury of fat dome in skin of pig.</p>

To ponder the key issues in achieving wound healing / 中华烧伤杂志

The understanding of the mechanism of wound healing is deepening. Key issues in the process of wound healing need to be seriously considered, i.e. how to establish the concept of application of phasic and selective means to promote wound healing according to the characteristics of a network and sequential process; to correctly assess the function and status of macrophages in wound healing and to explore the conditions of regulating timely infiltration of macrophages, as well as the phasic and orderly expression of type Iand type II macrophages; to properly understand the role and status of extracellular matrix components or the three-dimensional structure and morphology in wound healing; to elucidate the effects of wound microenvironment on the proliferation and differentiation of stem cells; to find out the intrinsic mechanism of negative pressure in the process of wound healing. The understanding of the above problems are of great value for us to grasp the intrinsic mechanism of wound healing in order to establish a more effective and rational treatment of wound.

Infiltration of macrophages and their phenotype in the healing process of full-thickness wound in rat / 中华烧伤杂志

<p><b>OBJECTIVE</b>To study the infiltration of macrophages and their phenotype in the healing process of full-thickness wound in rat.</p><p><b>METHODS</b>Thirty healthy SD rats were divided into control group (n = 6) and injury group (n = 24) according to the random number table. Two round full-thickness skin defects (11 mm diameter) were created on both sides of dorsal spine of rats in injury group with surgical scissors and homemade trephine. After injury, wound area was measured immediately. The wounds were disinfected with iodophor every day. Rats in control group received anesthesia and hair removal only. On post injury day (PID) 1, 3, 7, and 13, respectively, 6 rats of injury group were sacrificed after the measurement of wound area (wound healing rate was calculated). Wound samples were obtained by excision down to healthy fascia along wound edge. Histological study was done with HE staining. The expression of CD68 (the surface marker of macrophage) in the wound tissue was observed with immunohistochemical staining. The double positive expressions of induced nitric oxide synthase (iNOS) plus CD68 (type I macrophage) and arginase 1 (Arg-1) plus CD68 (type II macrophage) were observed with immunofluorescence staining. The levels of interferon-γ (IFN-γ), TNF-α, IL-4, IL-13, IL-10, and IL-12 in wound tissue were assayed by double-antibody sandwich ELISA, and the ratio of IL-10/IL-12 was calculated. Full-thickness skin tissues (11 mm diameter) in rats of control group were excised at the same site as rats in injury group, and the histological observation and cytokines assay were performed as well. Data were processed with one-way analysis of variance or LSD- t test.</p><p><b>RESULTS</b>Wound area of rats in injury group was gradually reduced after injury, and the overall difference of the wound healing rate on each PID was statistically significant (F = 358.55, P < 0.01). No abnormal appearance of skin tissue was observed in rats of control group. In injury group, inflammatory cell infiltration was obvious in wound tissue on PID 1 and 3; vascular structure and fresh collagen were observed in wound tissue on PID 7 and 13. Numbers of CD68 positive cells in skin tissue of rats in control group and wound tissue of rats in injury group on PID 1, 3, 7, and 13 were respectively (2.7 ± 1.5), (31.8 ± 3.5), (40.8 ± 4.7), (20.8 ± 2.8), (3.2 ± 2.4) per 200 times visual field (F = 180.55, P < 0.01). Compared with that in control group, the number of CD68 positive cells of rats in injury group was increased on PID 1, 3, and 7 (with t values respectively 18.81, 18.79, 14.05, P values below 0.01). No double positive expression of iNOS plus CD68 or Arg-1 plus CD68 was observed in normal tissue of rats in control group. In injury group, proportions of iNOS plus CD68 double positive cells on PID 1, 3, 7, and 13 were respectively (12.2 ± 2.8)%, (16.5 ± 2.9)%, (4.2 ± 2.3)%, (0.7 ± 0.8)% (F = 72.50, P < 0.01); proportions of Arg-1 plus CD68 double positive cells on PID 1, 3, 7, and 13 were respectively 0, (8.2 ± 1.9)%, (21.5 ± 3.4)%, (4.7 ± 2.0)% (F = 120.93, P < 0.01). In injury group, proportion of iNOS plus CD68 double positive cells on PID 3 was significantly higher than that on other PID (with t values respectively 2.65, 8.17, 12.95, P values below 0.05); proportion of Arg-1 plus CD68 double positive cells on PID 7 was higher than that on other PID (with t values respectively 15.27, 8.25, 10.38, P values below 0.01). Compared with that of Arg-1 plus CD68 double positive cells, proportion of iNOS plus CD68 double positive cells was higher on PID 1 and 3 (with t values respectively 10.71 and 5.88, P values below 0.01) and lower on PID 7 and 13 (with t values respectively 10.24 and 4.60, P values below 0.01). The overall differences of IFN-γ, TNF-α, IL-4, IL-13, and IL-10/IL-12 ratio in skin tissue of rats in control group and wound tissue of rats in injury group on every PID were statistically significant (with F values from 14.08 to 631.03, P values below 0.01). Compared with those in control group, levels of IFN-γ, TNF-α, IL-4, and IL-13 in wound tissue of rats in injury group were significantly higher on every PID (with t values from 4.58 to 9.17, P values below 0.05), while IL-10/IL-12 ratio was significantly higher on PID 1, 3, and 7 (with t values respectively 27.70, 30.51, 9.49, P values below 0.05) . In injury group, IFN-γ level on PID 1 [(61 ± 5) pg/mL] and IL-10/IL-12 ratio on PID 3 (1.647 ± 0.098) were significantly higher than those of control group and those on other PID in injury group [with IFN-γ level respectively (32 ± 4), (54 ± 6), (46 ± 7), (47 ± 4) pg/mL and IL-10/IL-12 ratio respectively 0.328 ± 0.045, 0.960 ± 0.034, 0.530 ± 0.028, 0.289 ± 0.040, with t values respectively from 3.19 to 8.20 and from 16.59 to 31.84, P values below 0.05].</p><p><b>CONCLUSIONS</b>Macrophage infiltration increases in the healing process of full-thickness wound in rat with different phenotypes, among which type I macrophage appears in the inflammatory stage, and type II macrophage predominates in the proliferative stage.</p>

Advances in the research of treating refractory diabetic wounds with stem cells / 中华烧伤杂志

With the growth of aging society, China has become the country of population with the highest incidence of diabetes in the world. Diabetes leads to pathological changes in vascular and nervous system, rendering the diabetic skin fragile and hard to heal if wounded; in the end most diabetic wounds tend to become chronic skin ulcers. The refractory diabetic wound is the result of various endogenous and exogenous factors. It is a quite complicated pathophysiologic event which lacks an effective and specific therapeutic method in clinic. The use of stem cells could be a new approach of treating diabetic chronic wounds since they have a potential ability of self-renovation and multi-directional differentiation which will promote angiogenesis and wound healing process, thus be beneficial in the care of ischemia diseases of the lower limb. This article reviews basic theory of treating diabetic wound and the changes in microenvironment, and prompts many successful cases in curing refractory diabetic wounds.

Histology of collagen nodules from hypertrophic scars / 中华创伤杂志

Objective To detect the histological characteristics of collagen nodules from hypertrophic scars (HS) and investigate the origin of collagen nodules.Methods The scar tissues were collected from patients with plastic operation.Morphological characteristics of collagen nodules were observed by light microscopy of HE-stained sections; expressions of type Ⅰ /Ⅲ collagens were observed by polarized light microscopy of sirius red-stained sections; expression and distribution of myofibroblasts (MFb)-specific protein (α-smooth muscle actin,α-SMA) were observed by immunostaining in order to observe level of local tissue tension.Results Collagen nodules varied in shape,not only sphereshaped,and in size.Moreover,abundant fibroblasts (Fb) with large and light-stained nuclei were seen in the nodules compared to non-nodule area,indicating that the cells located in the modules were active.Some collagen nodules were composed largely of collagen type Ⅲ (green),but some mainly contained collagen type Ⅰ (red or yellow),indicating the difference in the time of nodule formation.α-SMA was expressed mainly in the deep dermis equivalent to the level of reticular layer of the new scar tissues (2 months after injury) ; α-SMA was expressed mainly in the nodules of the old scar tissues (2-10 years after injury),but almost not in non-nodule areas except for a strongly positive staining in the vessels.Moreover,α-SMA presented a heterogeneous distribution in the collagen nodules,with stronger expression in the epidermal end than in the subcutaneous tissue end and stronger expression in the superficial dermis than that in the deeper part.It was suggested that there existed massive amount of MFb and high tension in the nodules arid that the tension distribution was not uniform in or between the nodules.Conclusions Collagen nodules are of varying shape and size and collagen types are associated with the time of nodule formation.Moreover,Formation of the collagen nodules may be closely related to the distribution and evolution of the local tissue tension.

Prognostic factors for diabetic foot ulcer / 中华创伤杂志

Objective To identify the factors related to prognosis of diabetic foot ulcer (DFU).Methods A total of 186 patients with type Ⅱ DFU from a single diabetic foot center was included in this prospective study.Follow-up of the final outcome (healing,major amputation or death) was made in 6 months.Influence of patient demographics and clinical data on outcome was detected using multivariate Logistic regression analysis.Results Follow-up was performed in 172 patients,of whom 147 were cured (55 cases cured after minor amputations),3 underwent major amputations,6 died,and 16 were not yet cured at the final follow-up.In multivariate Logistic regression analysis,the outcome was independently correlated with ischemia (P ＜0.01),infection (P ＜ 0.05),ulcer number (P ＜ 0.01) and peripheral neuropathy (P ＜ 0.05) ; the risk of poor outcome increased with ischemia [odds ratio (OR) =10.8],infection (OR =211.4),ulcer number (OR =39.5),and peripheral neuropathy (OR =181.1).Conclusion Prognosis of DFU is associated with ischemia,infection,ulcer number,and peripheral neuropathy.

Mechanism of the skin lesions in diabeitic rats / 中华内分泌代谢杂志

Four weeks after SD diabetic rats were induced by streptozotocin,skin thickness was obviously reduced with obscure multilayer epithelium features.Moreover,the thickness of epidermic layers in diabetic rat skin was significantly thinner than that ofnornlal rat skin at the eighth week[(0.016±0.006 vs 0.041±0.007)mm,P<0.01].The percentage of G2/M phase cells in epidermic layers of diabetic group was significantly lower than that in the normal group.At the twelfth week,skin microangiopathy was easily detected in the diabetic group.The blood levels of advanced glycation end products(AGEs)and malonialdehyde were significantly increased and glutathione decreased in diabetic rats compared with control rats(aU P<0.01),along with the increased contents of local glucose and AGEs in the skin of diabetic rats.These results suggest that the local accumulation of glucose and AGEs seems to be one of the important mechanisms in the pathogenesis of diabetic skin lesions.

Reseach on epidermal keratinocyte function impairing in rats with diabetes mellitus / 中华老年医学杂志

Objective To explore the effect of diabetes mellitus (DM) on biological behavior of epidermal keratinocyte in rats. Methods A total of 40 Sprague-Dawley rats were randomized into control group and streptozotocin (STZ) -induced diabetes group. Of each group, 10 rats were implemented with deep partial-thickness scalding. The re-epithelialization rate was observed at the 3rd, 7th, 14th and 21th post-burn day. Histological characteristics and thickness of epidermal tissue in both groups were observed. The adhesion rate, cell cycles, apoptosis rate and migration ability of keratinocyte were measured. The accumulation of advanced glycosylation end products (AGEs) of epidermal tissue was observed. Results The percentages of re-epithelialized area at the 7th, 14th and 21th post-burn day were much lower in DM group than in control group (P<0.05). In DM group, the epidermal thickness was reduced obviously with obscure multilayered epithelium and less amount of prickle cells; The adhesion rates of 12, 24 h after culturing keratinocyte and the percentage of G2/M phase cells were lower in DM group than in control group (P<0.05). However, apoptosis rate of keratinocyte was higher, the amount of migration cell was significantly less in DM group than in control group (both P<0.05). There were lots of AGEs accumulated in epidermal tissue in DM group, while there were hardly AGEs in control group. Conclusions Re-epithelization blocked exists on non-healing wound in DM rats, which is related with the impaired keratinocyte biological behavior. A large of AGEs accumulate in the epidermal tissue of DM rats, which may be a important reason to inhibit keratinocyte function in diabetic environment.

Clincal study of treatment for refractory diabetic wound / 中华创伤杂志

Objective To explore the repair method for refractory diabetic wound. Methods A total of 206 patients with refractory diabetic foot ulcers were treated with proper surgical treatments.Results Of all, 106 patients were treated by skin flap (51.5 % ), with one stage wound healing rate of 85.8%; 122 patients were repaired with split-thickness skin graft ( 59.2% ), with survival rate of the graft for 79.5%. Simple toe amputation was made in 34 patients (46 toes). The high level amputation was performed in 56 patients (27.2%). Of all, 132 patients were followed up for 6-18 months, which showed that ulcer recurred in 12 patients (9.1%). Conclusion Timely and effective treatment as well as flap and skin graft repair could reduce high level amputation rate of diabetic foot ulcer and promote the quality of life.

Effect of tension on collagen arrangement / 中华创伤杂志

Objective To study the effect of mechanical tension on collagen arrangement and illustrate the relationship between tissue architecture and tension properties. Methods Cell morphologies, orientation and collagen arrangement of fibroblasts cultured in three different types of collagen gels with variation of mechanical tension were observed by phase contrast photomicrographs, light microscopy and transmission electron microscopy. Expression and distribution of a-smooth muscle actin (α-SMA) were investigated by immunohistochemistry. Results Phase contrast photomicrographs, light microscopy and transmission electron microscopy showed high level of tension distributed anisotropically in the monolayer gels and the anchored collagen gels, with bipolar shape of the fibroblasts, obvious polarity, arrangement of exogenous collagen fibres parallel to the long axis of the fibroblasts, especially prominent in monolayer gels. Low level of tension distributed isotropically was observed in floating collagen gels, with stellate morphology and arrangement of exogenous collagen fibres in a reticular array. Immunofluorescence showed that fibroblasts expressed high level of α-SMA protein distributed along the long axis of fibroblasts in the monolayer gels and the anchored collagen gels, especially in former ones. In contrast, few expression of α-SMA protein was found in floating collagen gels. Cell morphologies and orientation, expression and distribution of α-SMA as well as collagen arrangement of fibroblasts in the monolayer gels and the anchored collagen gels were similar to those in granulation tissue, whereas floating collagen gels resembled normal dermis or remodelled tissues. Conclusions Tissue architecture or morphology of the dermis are corresponding to tension proporties. Different tissue architectures are closely correlated with particular tension proporties.

Role of myofibroblasts in formation of hypertrophic scar / 中华创伤杂志

Objective To explore the role of myofibroblasts expressing α-smooth muscle actin (a-SMA) in hyperplastic scar formation.Methods Expression of α-SMA in normal skin and scar was examined by means of immunohistochemistry.The contents of myofibroblasts were measured and com-pared with that of hydroxyproline through cell culture.The contents of precollagen (pc β) , transforming growth factor β (TGF-β) and fibronectin in fibroblasts and myofibroblasts were assayed by ELISA.Results Vascular smooth muscle cells rather than other hypodermal cells expressed α-SMA in normal skin (P<0.01).The expression ofa-SMA was markedly increased up to 96.89% in hyperplastic scar tissues, with statistical difference compared with normal skin (P < 0.01).The contents of hydroxyproline (P <0.01) , pc (P <0.05) , TGF-β (P <0.01) and fibronectin (P <0.05) in myofibroblasts were significantly higher than those in fibroblasts.Conclusion Myofibroblasts play a key role in formation of hypertrophic scar.