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.

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.

Association between sarcopenia and nutritional status in hospitalized patients aged 80 years and over / 中华老年医学杂志

Objective To investigate the association between sarcopenia and nutritional status among inpatients aged 80 years and over.Methods A total of 120 patients aged ≥80 years admitted into geriatrics department of a third-grade first-class hospital in Shandong province who met inclusion and exclusion criteria were enrolled from March 2017 to March 2018 in this cross-sectional study.According to diagnostic criteria of Asian Working Group for Sarcopenia,patients were divided into the sarcopenia group and the non-sarcopenia group.General clinical data were collected.Nutritional assessment was validated by using Mini Nutritional Assessment(MNA)and the determined nutritional indexes of serum levels of hemoglobin and albumin.Univariate and multivariate analysis were used to analyze the association between sarcopenia and nutritional status.Results Of 120 inpatients aged ≥ 80,28 cases(23.3％)had sarcopenia,including 20 men(71.4％)and 8 women(28.6％).The incidences of sarcomenia were 1.4％ (1 case)in patients with normal nutritional status and 100％ (6 cases)in patients with malnutrition.Compared with the non-sarcopenia group,the sarcopenia group had lower levels of body mass index,serum hemoglobin,serum albumin and MNA scores[(20.0 ± 2.2) kg/m2 vs.(25.4±3.0)kg/m2,(34.5±3.4)g/L vs.(38.6±3.5)g/L,(114.4± 14.0)g/L vs.(127.3± 14.8) g/L,(8.8 ± 1.9) score vs.(12.7 ± 1.4) score,P ＜ 0.05].After adjustment for all covariates,multivariate Logistic regression analysis showed that MNA score was an independent risk factor for sarcopenia(OR =0.118,95％CI:0.026-0.530).Conclusions The incidence of sarcopenia is high in hospitalized patients aged 80 years and older.MNA score is an independent risk factor for sarcopenia.

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.

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.

Expression and significance of neutrophil surface adhesion molecules CD11b in type 2 diabetes mellitus patients with cytomegalovirus infection / 中国基层医药

Objective To study diagnosis significance of neutrophil surface adhesion molecules including CD11b,in type 2 diabetes mellitus patients with cytomegalovirus (CMV)infection.Methods Blood samples from 139 cases of type 2 diabetes mellitus patients were collected including 99 male and 40 female cases between Septem-ber 2011 and January 2015.Healthy male 20 cases and female 13 cases were collected as healthy control group from outpatients in the same period.Type 2 diabetes mellitus patients were divided into high active CMV infection group, CMV infection group and the negative control group,and healthy group as normal control group according to CMV -pp65 antigen detection.Neutrophil surface adhesion molecule CD11b was analyzed by flow cytometry and compared respectively.ROC curve of CD11b in 2 diabetes mellitus patients was made.Results The expression ratio of CD11b in high active CMV infection group and CMV infection group in type 2 diabetes mellitus patients was (41.25 ± 5.33)%.There was significant difference (P =0.019)compared with negative control group (61.13 ±5.28)% and there was significant difference (P =0.009)compared with negative control group (64.21 ±6.02)%;optimal cut -off value of CD11b in high active CMV infection group was 45.65%,the sensitivity was 100.00%,the specificity in high active CMV infection group was 60.12%,and the area under the receiver -operating curve(ROC)was 0.628;optimal cut -off value of CD11b in CMV infection group was 70.21%,the sensitivity of CD11b was 87.69%,the specificity of CD11b was 99.22%,and the area under of ROC of CD11b was 0.991.Conclusion The neutrophils CD11b expression in type 2 diabetes mellitus patients with CMV infection is down regulation.CD11b expression can be used as a laboratory diagnosis basis of CMV infection.

Structural basis of Zika virus helicase in recognizing its substrates

The recent explosive outbreak of Zika virus (ZIKV) infection has been reported in South and Central America and the Caribbean. Neonatal microcephaly associated with ZIKV infection has already caused a public health emergency of international concern. No specific vaccines or drugs are currently available to treat ZIKV infection. The ZIKV helicase, which plays a pivotal role in viral RNA replication, is an attractive target for therapy. We determined the crystal structures of ZIKV helicase-ATP-Mn(2+) and ZIKV helicase-RNA. This is the first structure of any flavivirus helicase bound to ATP. Comparisons with related flavivirus helicases have shown that although the critical P-loop in the active site has variable conformations among different species, it adopts an identical mode to recognize ATP/Mn(2+). The structure of ZIKV helicase-RNA has revealed that upon RNA binding, rotations of the motor domains can cause significant conformational changes. Strikingly, although ZIKV and dengue virus (DENV) apo-helicases share conserved residues for RNA binding, their different manners of motor domain rotations result in distinct individual modes for RNA recognition. It suggests that flavivirus helicases could have evolved a conserved engine to convert chemical energy from nucleoside triphosphate to mechanical energy for RNA unwinding, but different motor domain rotations result in variable RNA recognition modes to adapt to individual viral replication.

ClinicaI significance of T follicuLar helper cells in rheumatoid arthritis / 国际检验医学杂志

Objective To investigate the percentages of T follicuLar helper cells (Tfh)and interleukin-21(IL-21)in the plasma of patients with rheumatoid arthritis,and the immunological mechanism of Tfh cells in the development of rheumatoid arthritis. Methods According to ACR and DAS28,patients with rheumatoid arthritis were divided into low,moderate and high activity group.The percentages of CD3 + CD4 + CXCR+ 、CD3 + CD4 + ICOS+ and CD3 + CD4 + CXCR+ ICOS+ Tfh cells were detected by Flow Cytometry.While the levels of IL-21 、RF-IgM and anti-CCP in plasma were measured by ELlSA test.The analysis was performed by t-test and Spearman′s correlation analysis.Results The expression of CD3 + CD4 + CXCR+ ICOS+ Tfh cells in PBMCs of rheu-matoid arthritis was significantly higher than that in the normal controls(P <0.05).Meanwhile the results of the three rheumatoid arthritis groups(low,moderate and high activity groups)showed that the expression of Tfh increased accordingly(P <0.05).The expression of Tfh in rheumatoid arthritis was positively related with the levels of IL-21 ,ESR,CRP,RF and anti-CCP respectively. Conclusion The expression of Tfh and IL-21 increases significantly and is closely related to the disease activity in rheumatoid ar-thritis.The results indicate that the abnormality of Tfh may play an important role in the pathogenesis of rheumatoid arthritis.

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>

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>

Epidemiological study of the genes conferring aminoglycoside resistance in 36 strains of multidrug-resistant Acinetobacter baumannii / 中国感染与化疗杂志

Objective To investigate the prevalence of genes conferring aminoglycoside resistance in multidrug-resistant strains of Acinetobacter baumannii (MDR-ABA).Methods Multidrug-resistant A.baumannii strains were isolated during the period from August to November 2012 from patients in the affiliated hospital of Jiangsu University and the First Hospital of Zhen-jiang.Kirby-Bauer diffusion method was used to determine the susceptibility of these strains to antimicrobial agents.PCR was performed to detect the aminoglycoside resistance genes.Results The 36 MDR-ABA strains showed high resistance rates to most antimicrobial agents except cefoperazone-sulbactam.The prevalence of the genes conferring aminoglycoside resistance, aac (3)-I,aac (6’)-Ib,aph (3’)-I and armA,was 72.2% (26/36),72.2% (26/36),80.6% (29/36)and 80.6% (29/36), respectively.Conclusions The MDR-ABA strains in this study are highly resistant to antimicrobial agents,which is closely as-sociated with the genes conferring aminoglycoside resistance.